TY - JOUR TI - Characterization of Polyphenolics in the Seed Coat of Black Jamapa Bean (Phaseolus vulgarisL.) AU - Aparicio-Fernandez, Xochitl AU - Yousef, Gad G. AU - Loarca-Pina, Guadalupe AU - de Mejia, Elvira AU - Lila, Mary Ann T2 - Journal of Agricultural and Food Chemistry AB - The common bean contains phytochemicals, including phenolic compounds, which can provide health benefits to the consumer. Our objective was to characterize the polyphenolic compounds present in the seed coat of Black Jamapa bean and to test fractionation methods that permit the recovery of polyphenolics in their naturally occurring forms. A 100% methanol extract from seed coats was subjected to different chromatographic fractionation methods. Analysis by HPLC-MS revealed that a better separation of phytochemicals was achieved using direct silica gel fractionation, which allowed more accurate identification of compounds, especially of the flavonols. Anthocyanins, flavanol monomers, and heterogeneous flavanol oligomers up to hexamers were detected. To our knowledge, this is the first time that myricetin glycoside and proanthocyanidin oligomers containing (epi)-gallocatechin have been reported in the black bean. The fractionation methods used in this study produced large quantities of natural mixtures of flavonoids suitable for testing bioactivity and phytochemical interactions. DA - 2005/6// PY - 2005/6// DO - 10.1021/jf047802o VL - 53 IS - 11 SP - 4615-4622 J2 - J. Agric. Food Chem. LA - en OP - SN - 0021-8561 1520-5118 UR - http://dx.doi.org/10.1021/jf047802o DB - Crossref ER - TY - JOUR TI - Screening Growth and Root Formation in Cadmium-Treated Turfgrass Using a Whole-Plant Microculture System AU - Kuo, Yu-Jen AU - Chang, Yu-Sen AU - Lila, M. A. AU - Chiu, Hsin-Yi T2 - Journal of Plant Nutrition AB - Abstract Pollution of water and soil by heavy-metal byproducts of mining and industrial operations is an environmental problem in many parts of Taiwan. Bermudagrass (Cynodon dactylon) and seashore paspalum (Paspalum vaginatum Swartz) are two of the most saline-tolerant warm-season turfgrasses. A whole-plant microculture (WPMC) system has been developed that permits intact-root growth observation through a gelrite-solidified culture medium. To screen efficiently for potential whole-plant-level salt tolerance in these turfgrasses, root morphology was studied using scanning electron microscopy. Nodal explants at the same developmental stage as the plants were sterilized, and each explant was placed in a Pyrex test tube containing 25 mL of 1/2 Murashige and Skoog (MS) media with 30 g L− 1 sucrose, 1 mg L− 1 IBA, 0.1 mg 2ip, 2.5 g L− 1gelrite, and either 0, 1, or 100 ppm of CdCl2 stress media for five months. The experimental results demonstrated significant differences among stress media in terms of root number, root length, shoot length, nodal number, and ratio of root length to shoot length of plants. Moreover, scanning electron microscopy (SEM) examination of regenerated WPMC roots under cadmium (Cd)-free, 1, and 100 ppm of CdCl2 stress media revealed obvious morphological and adaptational differences. In this investigation, microculture at the whole-plant level in vitro enables intact root growth observations through the culture medium and vessel, and offers a potential pre-screening method for putative heavy-metal-tolerant turfgrasses before commercialization and use in phytoremediation to clean up contaminated soils. DA - 2005/6// PY - 2005/6// DO - 10.1081/PLN-200058903 VL - 28 IS - 6 SP - 1041-1048 J2 - Journal of Plant Nutrition LA - en OP - SN - 0190-4167 1532-4087 UR - http://dx.doi.org/10.1081/PLN-200058903 DB - Crossref KW - bermudagrass KW - seashore paspalum KW - whole-plant microculture KW - phytoremediation ER - TY - JOUR TI - Effects of Grape Cell Culture Extracts on Human Topoisomerase II Catalytic Activity and Characterization of Active Fractions AU - Jo, Jeong-Youn AU - Gonzalez de Mejia, Elvira AU - Lila, Mary Ann T2 - Journal of Agricultural and Food Chemistry AB - Grape and its cell culture extracts are rich in flavonoids and stilbenes that are biologically active. The objective of this study was to evaluate possible inhibitory effects of grape (a Vitis hybrid Bailey Alicant A) cell culture extract and subfractions on human DNA topoisomerase II catalytic activity and to characterize constituents in the most potent fractions. At 5 μg/mL, grape cell crude extract and Toyopearl (TP) fractions 2−6 provided significantly greater inhibition of topoisomerase II catalytic activity than quercetin, a chemopreventive agent previously known as a topoisomerase catalytic inhibitor. The most potent topoisomerase II catalytic inhibitors from grape cell culture extracts in descending order of potency were TP fractions 4 and 6 (IC50 = 0.28−0.29 μg/mL), TP-3 (IC50 = 0.74 μg/mL), and crude extract (IC50 = 1.02 μg/mL); each was significantly more potent than resveratrol (IC50 = 18.0 μg/mL), another well-known chemopreventive topoisomerase II catalytic inhibitor. Using both high-performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry, constituents in TP-4 and TP-6 were characterized. These constituents included cyanidin-3,5-diglucoside, malvidin-3-acetylglucoside, peonidin-3-coumaryl-5-diglucoside, procyanidin B1, procyanidin B2, procyanidin B5, procyanidin dimer digallate, procyanidin C1, myricetin, and rutin, none of which have been previously characterized from grape cell cultures. The significant potency especially of TP-4 and TP-6 from grape cell cultures suggests that these fractions may have potential as chemopreventive agents. Keywords: Human topoisomerase II; catalytic inhibitor; antitopoisomerase II activity; Vitis; grape cell culture; chemopreventive agents DA - 2005/4// PY - 2005/4// DO - 10.1021/jf048524w VL - 53 IS - 7 SP - 2489-2498 J2 - J. Agric. Food Chem. LA - en OP - SN - 0021-8561 1520-5118 UR - http://dx.doi.org/10.1021/jf048524w DB - Crossref KW - human topoisomerase II KW - catalytic inhibitor KW - antitopoisomerase II activity KW - Vitis KW - grape cell culture KW - chemopreventive agents ER - TY - JOUR TI - Thermal Degradation of Commercial Grade Sodium Copper Chlorophyllin AU - Ferruzzi, Mario G. AU - Schwartz, Steven J. T2 - Journal of Agricultural and Food Chemistry AB - Sodium copper chlorophyllin (SCC), a water-soluble commercial derivative of chlorophyll, has gained importance as a food colorant and dietary supplement with apparent chemopreventive activities. The thermal stability of SCC was studied to assess the potential application of this chlorophyll derivative for use in thermally processed foods and supplements. Thermal degradation of an aqueous 500 ppm SCC solution was monitored between 25 and 100 degrees C by a loss of absorbance at 627 nm. Decomposition was also followed by reversed phase C18 HPLC with photodiode array detection to monitor the loss of Cu(II)Chlorin e4, the major component of commercial grade SCC. The rate of thermal degradation of SCC was found to follow first-order reaction kinetics. HPLC analysis confirmed the ultraviolet and visible absorbance data and also demonstrated loss of the major SCC component, Cu(II)Chlorin e4, at a rate faster than that of overall SCC. The activation energy was estimated using the Arrhenius equation and found to be 13.3 +/- 0.8 and 16.0 +/- 2.1 kcal/mol for the thermal degradation of SCC and Cu(II)Chlorin e4, respectively. The observed temperature sensitivity of SCC was determined to be similar to that of natural chlorophyll and raises the possibility of color deterioration when used in food products where mild to severe thermal treatment is applied. Furthermore, the implication of rapid loss of Cu(II)Chlorin e4, a reported bioactive component of SCC, upon heating may result in alteration of potential dietary benefits such as antimutagenic and antioxidant activity. DA - 2005/9// PY - 2005/9// DO - 10.1021/jf051010s VL - 53 IS - 18 SP - 7098-7102 J2 - J. Agric. Food Chem. LA - en OP - SN - 0021-8561 1520-5118 UR - http://dx.doi.org/10.1021/jf051010s DB - Crossref KW - sodium copper chlorophyllin KW - Cu(II)chlorin e(4) KW - thermal degradation KW - UV-vis spectrophotometry KW - HPLC ER - TY - JOUR TI - Genomic features of lactic acid bacteria effecting bioprocessing and health AU - Klaenhammer, Todd R. AU - Barrangou, Rodolphe AU - Buck, B. Logan AU - Azcarate-Peril, M. Andrea AU - Altermann, Eric T2 - FEMS Microbiology Reviews AB - The lactic acid bacteria are a functionally related group of organisms known primarily for their bioprocessing roles in food and beverages. More recently, selected members of the lactic acid bacteria have been implicated in a number of probiotic roles that impact general health and well-being. Genomic analyses of multiple members of the lactic acid bacteria, at the genus, species, and strain level, have now elucidated many genetic features that direct their fermentative and probiotic roles. This information is providing an important platform for understanding core mechanisms that control and regulate bacterial growth, survival, signaling, and fermentative processes and, in some cases, potentially underlying probiotic activities within complex microbial and host ecosystems. DA - 2005/8// PY - 2005/8// DO - 10.1016/j.fmrre.2005.04.007 VL - 29 IS - 3 SP - 393-409 ER - TY - CHAP TI - Anthocyanins and Cancer Prevention AU - Holub, Bruce AU - Kay, Colin T2 - Nutrition and Cancer Prevention PY - 2005/9/19/ DO - 10.1201/9781420026399.ch20 OP - PB - CRC Press SN - 9780849339455 9781420026399 UR - http://dx.doi.org/10.1201/9781420026399.ch20 DB - Crossref ER - TY - JOUR TI - Anthocyanins exist in the circulation primarily as metabolites in adult men AU - Kay, Colin D AU - Mazza, Giuseppe AU - Holub, Bruce J T2 - The Journal of nutrition DA - 2005/// PY - 2005/// VL - 135 IS - 11 SP - 2582-2588 ER - TY - JOUR TI - Microbial Quality of Cool Water Washed Shell Eggs AU - Jones, D.R. AU - Musgrove, M.T. AU - Caudill, A.B. AU - Curtis, P.A. AU - Northcutt, J.K. T2 - International Journal of Poultry Science AB - 3 Abstract: A study was conducted to examine the effects of cool water washing on the microbial quality of shell eggs. Six dual tank wash water temperature schemes were examined for their ability to reduce naturally occurring aerobic bacteria and inoculated Salmonella Enteritidis (SE). The wash water schemes were: T1= 48.9 C; T2 = 48.9 C, 23.9 C; T3 = 48.9 C, 15.6 C; T4 = 23.9 C; T5 = 15.6 C; and T6 = 23.9 C, 15.6 C. All wash o o o o o o o o o water tanks were maintained from 10.5-11.5 pH throughout the study. Eggs were exposed to the wash water temperature schemes in a pilot egg washer with recirculating wash water tanks. The total amount of time eggs were exposed to the wash water combinations was 60 s. Following washing, all eggs were sprayed with a 48.9 C, 200 ppm chlorine rinse solution. Eggs were stored and sampled for 9 wks. External aerobic o populations were lowest for T1 (typical U.S. wash water configuration), followed by T2 and T3. Aerobic surface contamination was greatest in T5 eggs. All treatments reduced SE levels in a similar manner as detected by shell and membrane emulsion and egg contents pools after enrichment. Commercial application of cool water shell egg processing will be investigated to determine the potential of thi s technology to enhance the safety and quality of shell eggs. DA - 2005/// PY - 2005/// DO - 10.3923/ijps.2005.938.943 VL - 4 IS - 12 SP - 938--943 ER - TY - JOUR TI - Genomic Perspectives on Probiotic Lactic Acid Bacteria AU - Klaenhammer, Todd R. AU - Peril, Andrea Azcarate AU - Barrangou, Rodolphe AU - Duong, Tri AU - Altermann, Eric T2 - Bioscience and Microflora AB - The lactic acid bacteria are Gram-positive fermentative microorganisms known primarily for their roles as starter cultures and probiotics. The food industry represents one of the largest manufacturing industries in the world and recent trends are rapidly expanding the use of probiotic cultures within functional foods. Understanding and control of lactic acid bacteria is now being revolutionized by genomic sciences and the appearance of the complete genome sequences for Bifidobacterium longum, Lactobacillus johnsonii, Lactobacillus plantarum, and draft sequences for Lactobacillus gasseri and Lactobacillus casei. This explosion of DNA sequence information, accompanied by the development of bioinformatic tools for nucleic acid and protein analysis, now allows rapid characterization of the lactic acid bacteria for their genomic content and expression profiles across the entire genome. Comparative genomics has already revealed important similarities and differences in strains, species, and genera and will likely identify key genetic features responsible for the beneficial properties ascribed to probiotic lactic acid bacteria. Practical genomics for the lactic acid bacteria promises to establish the genetic landscape, correlate genotypes with desirable phenotypes, establish genetic criteria for strain selection, improve culture stability by stress preconditioning, provide opportunities for metabolic engineering, and uncover a mechanistic basis for the beneficial activities of probiotics when delivered in various foods. This presentation will examine the genomic content of probiotic Lactobacillus cultures, compared to those lactic acid bacterial genomes that have appeared recently. In addition, expression profiling by whole genome microarrays will be used to illustrate how environmental conditions encountered during biomanufacturing, fermentation, and the gastrointestinal tract can impact gene expression and culture functionality. DA - 2005/// PY - 2005/// DO - 10.12938/bifidus.24.31 VL - 24 IS - 2 SP - 31-33 ER - TY - JOUR TI - Adapting a core service-learning model for wide-ranging implementation: An institutional case study AU - Clayton, P. H. AU - Ash, S. L. AU - Bullard, L. G. T2 - Creative College Teaching Journal DA - 2005/// PY - 2005/// VL - 2 IS - 1 SP - 10-26 ER - TY - JOUR TI - Molecular characterization of Listeria monocytogenes of the serotype 4b complex (4b, 4d, 4e) from two turkey processing plants AU - Eifert, J. D. AU - Curtis, P. A. AU - Bazaco, M. C. AU - Meinersmann, R. J. AU - Berrang, M. E. AU - Kernodle, S. AU - Stam, C. AU - Jaykus, L. -A. AU - Kathariou, S. T2 - FOODBORNE PATHOGENS AND DISEASE AB - Most foodborne outbreaks of listeriosis have been found to involve a small number of closely related strains of Listeria monocytogenes serotype 4b. The ecology of these organisms and their reservoirs in nature or in the processing plant environment, however, remain poorly understood. Surveys of environmental samples from two turkey processing plants in the United States indicated presence of L. monocytogenes of the serotype 4b complex (serotype 4b and the closely related serotypes 4d and 4e). In addition, environmental and raw product samples from one plant repeatedly yielded isolates with genetic markers typical of two major serotype 4b epidemic clonal groups, ECI and ECII. The pulsed field gel electrophoresis (PFGE) profiles of these isolates, however, were clearly distinct from those of confirmed epidemic-associated strains. Furthermore, we observed minor but consistent differences in PFGE profiles of isolates that harbored ECI- or ECII-specific genetic markers, and that were obtained at different sampling times from the same plant. The findings suggest processing plant persistence (or repeated introductions) and genomic diversification of L. monocytogenes serotype 4b isolates that harbor ECI- or ECII-specific genetic markers. Such diversification would need to be taken into consideration in further efforts to elucidate the evolution and epidemiology of these organisms. DA - 2005/// PY - 2005/// DO - 10.1089/fpd.2005.2.192 VL - 2 IS - 3 SP - 192-200 SN - 1556-7125 ER - TY - PAT TI - Apparatus and method for controlling flow of process materials AU - Cartwright, G. D. C2 - 2005/// DA - 2005/// PY - 2005/// ER - TY - JOUR TI - Strain persistence and fluctuation of multiple-antibiotic resistant Campylobacter coli colonizing turkeys over successive production cycles AU - Lee, Bong Choon AU - Reimers, Nancy AU - Barnes, H. John AU - D'Lima, Carol AU - Carver, Donna AU - Kathariou, Sophia T2 - FOODBORNE PATHOGENS AND DISEASE AB - The dynamics of colonization of turkeys by thermophilic campylobacters that are resistant to multiple antibiotics is poorly understood. In this study, we monitored cecal colonization of turkeys by Campylobacter over three successive production cycles at the same farm. Campylobacter isolated from the ceca was predominantly C. coli in all three flocks. Isolates with two distinct fla types that represented a single clonal group based on pulsed-field gel electrophoresis and that were resistant to multiple antibiotics (tetracycline, streptomycin, ampicillin, erythromycin, kanamycin, nalidixic acid, and ciprofloxacin) predominated throughout the three production cycles. The relative prevalence of each fla type, however, varied significantly from one flock to the next. The repeated isolation of these multiresistant C. coli from successive flocks likely reflected persistence of the organisms in currently unknown reservoirs in the production environment or, alternatively, repeated introduction events followed by establishment of these bacteria in each successive flock. DA - 2005/// PY - 2005/// DO - 10.1089/fpd.2005.2.103 VL - 2 IS - 1 SP - 103-110 SN - 1556-7125 ER - TY - JOUR TI - The influence of aminoethoxyvinylglycine and ethephon on objective and sensory quality of 'Delicious' apples and apple juice at harvest and after storage AU - Drake, S. R. AU - Eisele, T. A. AU - Drake, M. A. AU - Elfving, D. C. AU - Drake, S. L. AU - Visser, D. B. T2 - HortScience DA - 2005/// PY - 2005/// VL - 40 IS - 7 SP - 2102-2108 ER - TY - JOUR TI - Microarray analysis of a two-component regulatory system involved in acid resistance and proteolytic activity in Lactobacillus acidophilus AU - Azcarate-Peril, MA AU - McAuliffe, O AU - Altermann, E AU - Lick, S AU - Russell, WM AU - Klaenhammer, TR T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - Two-component regulatory systems are one primary mechanism for environmental sensing and signal transduction. Annotation of the complete genome sequence of the probiotic bacterium Lactobacillus acidophilus NCFM revealed nine two-component regulatory systems. In this study, the histidine protein kinase of a two-component regulatory system (LBA1524HPK-LBA1525RR), similar to the acid-related system lisRK from Listeria monocytogenes (P. D. Cotter et al., J. Bacteriol. 181:6840-6843, 1999), was insertionally inactivated. A whole-genome microarray containing 97.4% of the annotated genes of L. acidophilus was used to compare genome-wide patterns of transcription at various pHs between the control and the histidine protein kinase mutant. The expression pattern of approximately 80 genes was affected by the LBA1524HPK mutation. Putative LBA1525RR target loci included two oligopeptide-transport systems present in the L. acidophilus genome, other components of the proteolytic system, and a LuxS homolog, suspected of participating in synthesis of the AI-2 signaling compound. The mutant exhibited lower tolerance to acid and ethanol in logarithmic-phase cells and poor acidification rates in milk. Supplementation of milk with Casamino Acids essentially restored the acid-producing ability of the mutant, providing additional evidence for a role of this two component system in regulating proteolytic activity in L. acidophilus. DA - 2005/10// PY - 2005/10// DO - 10.1128/AEM.71.10.5794-5804.2005 VL - 71 IS - 10 SP - 5794-5804 SN - 1098-5336 ER - TY - JOUR TI - Mechanical properties of foods used in experimental studies of primate masticatory function AU - Williams, SH AU - Wright, BW AU - Den Truong, V AU - Daubert, CR AU - Vinyard, CJ T2 - AMERICAN JOURNAL OF PRIMATOLOGY AB - In vivo studies of jaw-muscle behavior have been integral factors in the development of our current understanding of the primate masticatory apparatus. However, even though it has been shown that food textures and mechanical properties influence jaw-muscle activity during mastication, very little effort has been made to quantify the relationship between the elicited masticatory responses of the subject and the mechanical properties of the foods that are eaten. Recent work on human mastication highlights the importance of two mechanical properties-toughness and elastic modulus (i.e., stiffness)-for food breakdown during mastication. Here we provide data on the toughness and elastic modulus of the majority of foods used in experimental studies of the nonhuman primate masticatory apparatus. Food toughness ranges from approximately 56.97 Jm(-2) (apple pulp) to 4355.45 Jm(-2) (prune pit). The elastic modulus of the experimental foods ranges from 0.07 MPa for gummy bears to 346 MPa for popcorn kernels. These data can help researchers studying primate mastication select among several potential foods with broadly similar mechanical properties. Moreover, they provide a framework for understanding how jaw-muscle activity varies with food mechanical properties in these studies. DA - 2005/11// PY - 2005/11// DO - 10.1002/ajp.20189 VL - 67 IS - 3 SP - 329-346 SN - 1098-2345 KW - mechanical properties KW - fracture toughness KW - elastic modulus KW - etectromyography ER - TY - JOUR TI - Denaturation and aggregation of three alpha-lactalbumin preparations at neutral pH AU - McGuffey, MK AU - Epting, KL AU - Kelly, RM AU - Foegeding, EA T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - The denaturation and aggregation of reagent-grade (Σα-La), ion-exchange chromatography purified (IEXα-La), and a commercial-grade (Cα-La) α-lactalbumin were studied with differential scanning calorimetry (DSC), polyacrylamide gel electrophoresis, and turbidity measurement. All three preparations had similar thermal denaturation temperatures with an average of 63.7 °C. Heating pure preparations of α-lactalbumin produced three non-native monomer species and three distinct dimer species. This phenomenon was not observed in Cα-La. Turbidity development at 95 °C (τ95°C) indicated that pure preparations rapidly aggregate at pH 7.0, and evidence suggests that hydrophobic interactions drove this phenomenon. The Cα-La required 4 times the phosphate or excess Ca2+ concentrations to develop a similar τ95°C to the pure preparations and displayed a complex pH-dependent τ95°C behavior. Turbidity development dramatically decreased when the heating temperature was below 95 °C. A mechanism is provided, and the interrelationship between specific electrostatic interactions and hydrophobic attraction, in relation to the formation of disulfide-bonded products, is discussed. Keywords: α-Lactalbumin; whey proteins; denaturation and aggregation DA - 2005/4/20/ PY - 2005/4/20/ DO - 10.1021/jf048863p VL - 53 IS - 8 SP - 3182-3190 SN - 1520-5118 KW - alpha-lactalbumin KW - whey proteins KW - denaturation and aggregation ER - TY - JOUR TI - Characterization of aroma compounds responsible for the rosy/floral flavor in cheddar cheese AU - Whetstine, MEC AU - Cadwallader, KR AU - Drake, MA T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - The aroma-active compounds that contribute to the rosy/floral flavor in Cheddar cheese were characterized using both instrumental and sensory techniques. Two cheeses (>12 months old) with rosy/floral flavor and two Cheddar cheeses of similar ages without rosy/floral flavors were selected. After direct solvent extraction/solvent-assisted flavor evaporation and separation into neutral/basic and acidic fractions, samples were analyzed by gas chromatography−olfactometry with aroma extract dilution analysis. Selected compounds were quantified using internal standard methodology. Some of the intense aroma-active compounds in the neutral basic fraction of the rosy/floral cheeses included 2-phenethanol (rosy), phenylethyl acetate (rosy), and phenylacetaldehyde (rosy/floral). Quantification, threshold analysis, and sensory analysis of model cheeses confirmed that increased concentrations of phenylacetaldehyde and phenylacetic acid caused rosy/floral flavor when spiked into Cheddar cheese. Keywords: Cheddar cheese flavor; GC-O; sensory analysis; threshold determination; model systems DA - 2005/4/20/ PY - 2005/4/20/ DO - 10.1021/jf048278o VL - 53 IS - 8 SP - 3126-3132 SN - 1520-5118 KW - cheddar cheese flavor KW - GC-O KW - sensory analysis KW - threshold determination KW - model systems ER - TY - JOUR TI - The screening of chemicals for juvenoid-related endocrine activity using the water flea Daphnia magna AU - Wang, HY AU - Olmstead, AW AU - Li, H AU - LeBlanc, GA T2 - AQUATIC TOXICOLOGY AB - U.S. Environmental Protection Agency is charged with developing a screening and testing paradigm for detecting endocrine toxicity of chemicals that are subject to regulation under the Food Quality Protection and the Safe Drinking Water Acts. In this study, we developed and evaluated a screening assay that could be employed to detect juvenoid-related endocrine-modulating activity in an invertebrate species. Juvenoid activity, anti-juvenoid activity, and juvenoid potentiator activity of chemicals was assessed using the water flea Daphnia magna. Male sex determination is under the regulatory control of juvenoid hormone, presumably methyl farnesoate, and this endpoint was used to detect juvenoid modulating activity of chemicals. Eighteen chemicals were evaluated for juvenoid agonist activity. Positive responses were detected with the juvenoid hormones methyl farnesoate and juvenile hormone III along with the insect growth regulating insecticides pyriproxyfen, fenoxycarb, and methoprene. Weak juvenoid activity also was detected with the cyclodiene insecticide dieldrin. Assays performed repetitively with compounds that gave either strong positive, weak positive, or negative response were 100% consistent indicating that the assay is not prone to false positive or negative responses. Five candidate chemicals were evaluated for anti-juvenoid activity and none registered positive. Four chemicals (all trans-retinoic acid, methoprene, kinoprene, bisphenol A) also were evaluated for their ability to potentiate the activity of methyl farnesoate. All registered positive. Results demonstrate that an in vivo assay with a crustacean species customarily employed in toxicity testing can be used to effectively screen chemicals for juvenoid-modulating activity. DA - 2005/9/10/ PY - 2005/9/10/ DO - 10.1016/j.aquatox.2005.05.010 VL - 74 IS - 3 SP - 193-204 SN - 1879-1514 KW - endocrine disruptors KW - screening KW - juvenoids KW - sex determination ER - TY - JOUR TI - Putative transposases conserved in Exiguobacterium isolates from ancient Siberian permafrost and from contemporary surface habitats AU - Vishnivetskaya, TA AU - Kathariou, S T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - ABSTRACT Gram-positive bacteria of the genus Exiguobacterium have been repeatedly isolated from Siberian permafrost ranging in age from 20,000 to 2 to 3 million years and have been sporadically recovered from markedly diverse habitats, including microbial mats in Lake Fryxell (Antarctic), surface water, and food-processing environments. However, there is currently no information on genomic diversity of this microorganism or on the physiological strategies that have allowed its survival under prolonged freezing in the permafrost. Analysis of the genome sequence of the most ancient available Exiguobacterium isolate ( Exiguobacterium sp. strain 255-15, from 2 to 3 million-year-old Siberian permafrost) revealed numerous putative transposase sequences, primarily of the IS 200 /IS 605 , IS 30 , and IS 3 families, with four transposase families identified. Several of the transposase genes appeared to be part of insertion sequences. Southern blots with different transposase probes yielded high-resolution genomic fingerprints which differentiated the different permafrost isolates from each other and from the Exiguobacterium spp. type strains which have been derived from diverse surface habitats. Each of the Exiguobacterium sp. strain 255-15 transposases that were used as probes had highly conserved homologs in the genome of other Exiguobacterium strains, both from permafrost and from modern sites. These findings suggest that, prior to their entrapment in permafrost, Exiguobacterium isolates had acquired transposases and that conserved transposases are present in Exiguobacterium spp., which now can be isolated from various modern surface habitats. DA - 2005/11// PY - 2005/11// DO - 10.1128/AEM.71.11.6954-6962.2005 VL - 71 IS - 11 SP - 6954-6962 SN - 1098-5336 ER - TY - JOUR TI - Physical, chemical and microbial changes in shredded sweet potatoes AU - McConnell, R AU - Truong, VD AU - Walter, WM AU - McFeeters, RF T2 - JOURNAL OF FOOD PROCESSING AND PRESERVATION AB - With the increasing demand for freshly cut vegetables, a substantial potential exists in developing minimally processed sweet potato products. This study was undertaken to determine the effects of semipermeable polymeric materials and modified atmosphere packaging (MAP) on quality changes and microbial growth in shredded sweet potatoes under refrigerated storage. Shredded sweet potatoes from two major commercial cultivars (Beauregard and Hernandez) were packed in low and medium O 2 permeability bags and flushed with gas composed of 5% O 2 , 4% CO 2 and 91% N 2 . Quality changes and microbial growth were monitored in comparison to the samples packed in air using high-O 2 permeable films. The quality of shredded sweet potatoes could be maintained for 7 days at 4C in air, but extended up to 14 days in MAP. Considering the parameters measured in this investigation, the best results were obtained by MAP using moderately O 2 -permeable film (7000 cm 3 /atm/m 2 /24 h). Shredded sweet potatoes stored in MAP showed less changes in tissue firmness, dry matter, ascorbic acid and starch than shredded sweet potatoes stored in air. The MAP-stored shredded sweet potatoes consistently exhibited fewer total aerobic bacteria and enteric bacteria compared to the shredded sweet potatoes stored in air. Yeasts, molds, lactic acid bacteria, color, beta-carotene and sugars of all stored shredded sweet potatoes did not significantly change, regardless of treatments. Higher ethanol levels were generated in the MAP-stored shredded sweet potatoes after 10 days, but off-odors were not detected in any of the MAP-stored shredded sweet potatoes. DA - 2005/// PY - 2005/// DO - 10.1111/j.1745-4549.2005.00026.x VL - 29 IS - 3-4 SP - 246-267 SN - 1745-4549 ER - TY - JOUR TI - Inhibition of protease in intact fish fillets by soaking in or injection of recombinant soy cystatin or bovine plasma AU - Kang, I AU - Lanier, TC T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - Arrowtooth flounder (AF) fillets are known to contain a heat-activated cysteine protease similar to that found in Pacific whiting, which results in soft texture upon cooking. A crude recombinant soy cystatin (CRSC) produced by Escherichia coli, which has been shown to inhibit the protease(s) in Pacific whiting, was introduced into AF fillets by immersion or injection at one of three levels of inhibitory activity: 10 times less than, equal to, or 10 times greater than that of a 20% bovine plasma protein (BPP) solution, a known inhibitor of AF protease(s). Fillets treated with CRSC or BPP at equal inhibitory strength subsequently exhibited the same degree of protection against textural degradation during cooking. Fillets treated with CRSC at lesser or greater levels of inhibitory activity than those of BPP exhibited lesser or higher protection, accordingly. As revealed by SDS−PAGE, the outer portion of fillets soaked with inhibitory solutions was more effectively protected than the inner portion. Such differences between the outer and inner portions of the fillets were not evident when inhibitory solutions were injected into the fillets. Keywords: Protease inhibitor; arrowtooth flounder; immersion; injection; cystatin; recombinant; bovine plasma protein DA - 2005/12/14/ PY - 2005/12/14/ DO - 10.1021/jf051231y VL - 53 IS - 25 SP - 9795-9799 SN - 0021-8561 KW - protease inhibitor KW - arrowtooth flounder KW - immersion KW - injection KW - cystatin KW - recombinant KW - bovine plasma protein ER - TY - JOUR TI - Aseptic processing of sweetpotato purees using a continuous flow microwave system AU - Coronel, P. AU - Truong, Simunovic J. Van-Den AU - Sandeep, KP AU - Cartwright, G. D. T2 - Journal of Food Science AB - ABSTRACT: Sweetpotato purees (SPP) were aseptically processed using a continuous flow microwave system to obtain a shelf-stable product. The dielectric properties of SPP were measured, and the dielectric constant and loss factor were within the range of the published values for fruits and vegetables. Small-scale tests were conducted in a 5-kW microwave unit to determine changes in color and viscosity with different thermal treatments. The results of these tests showed that color values (L*, a*) and viscosity did not change significantly compared with the untreated control. Pilot-scale tests were then conducted in a 60-kW microwave unit where the product was heated to 135 °C and held at that temperature for 30 s. The pilot-scale test produced a shelf-stable product with no detectable microbial count during a 90-d storage period at room temperature. This is the 1st report of aseptically packaged vegetable puree processed by a continuous flow microwave heating system. DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb08315.x VL - 70 IS - 9 SP - E531–536 ER - TY - JOUR TI - A field study of the microbiological quality of fresh produce AU - Johnston, LM AU - Jaykus, LA AU - Moll, D AU - Martinez, MC AU - Anciso, J AU - Mora, B AU - Moe, CL T2 - JOURNAL OF FOOD PROTECTION AB - The Centers for Disease Control and Prevention has reported that foodborne disease outbreaks associated with fruits and vegetables increased during the past decade. This study was conducted to characterize the routes of microbial contamination in produce and to identify areas of potential contamination from production through postharvest handling. We report here the levels of bacterial indicator organisms and the prevalence of selected pathogens in produce samples collected from the southern United States. A total of 398 produce samples (leafy greens, herbs, and cantaloupe) were collected through production and the packing shed and assayed by enumerative tests for total aerobic bacteria, total coliforms, total Enterococcus, and Escherichia coli. These samples also were analyzed for Salmonella, Listeria monocytogenes, and E. coli O157:H7. Microbiological methods were based on methods recommended by the U.S. Food and Drug Administration. For all leafy greens and herbs, geometric mean indicator levels ranged from 4.5 to 6.2 log CFU/g (aerobic plate count); less than 1 to 4.3 log CFU/g (coliforms and Enterococcus); and less than 1 to 1.5 log CFU/g (E. coli). In many cases, indicator levels remained relatively constant throughout the packing shed, particularly for mustard greens. However, for cilantro and parsley, total coliform levels increased during the packing process. For cantaloupe, microbial levels significantly increased from field through packing, with ranges of 6.4 to 7.0 log CFU/g (aerobic plate count); 2.1 to 4.3 log CFU/g (coliforms); 3.5 to 5.2 log CFU/g (Enterococcus); and less than 1 to 2.5 log CFU/g (E. coli). The prevalence of pathogens for all samples was 0, 0, and 0.7% (3 of 398) for L. monocytogenes, E. coli O157:H7, and Salmonella, respectively. This study demonstrates that each step from production to consumption may affect the microbial load of produce and reinforces government recommendations for ensuring a high-quality product. DA - 2005/9// PY - 2005/9// DO - 10.4315/0362-028X-68.9.1840 VL - 68 IS - 9 SP - 1840-1847 SN - 1944-9097 ER - TY - JOUR TI - Functional analysis of putative adhesion factors in Lactobacillus acidophilus NCFM AU - Buck, BL AU - Altermann, E AU - Svingerud, T AU - Klaenhammer, TR T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - ABSTRACT Lactobacilli are major inhabitants of the normal microflora of the gastrointestinal tract, and some select species have been used extensively as probiotic cultures. One potentially important property of these organisms is their ability to interact with epithelial cells in the intestinal tract, which may promote retention and host-bacterial communication. However, the mechanisms by which they attach to intestinal epithelial cells are unknown. The objective of this study was to investigate cell surface proteins in Lactobacillus acidophilus that may promote attachment to intestinal tissues. Using genome sequence data, predicted open reading frames were searched against known protein and protein motif databases to identify four proteins potentially involved in adhesion to epithelial cells. Homologous recombination was used to construct isogenic mutations in genes encoding a mucin-binding protein, a fibronectin-binding protein, a surface layer protein, and two streptococcal R28 homologs. The abilities of the mutants to adhere to intestinal epithelial cells were then evaluated in vitro. Each strain was screened on Caco-2 cells, which differentiate and express markers characteristic of normal small-intestine cells. A significant decrease in adhesion was observed in the fibronectin-binding protein mutant (76%) and the mucin-binding protein mutant (65%). A surface layer protein mutant also showed reduction in adhesion ability (84%), but the effect of this mutation is likely due to the loss of multiple surface proteins that may be embedded in the S-layer. This study demonstrated that multiple cell surface proteins in L. acidophilus NCFM can individually contribute to the organism's ability to attach to intestinal cells in vitro. DA - 2005/12// PY - 2005/12// DO - 10.1128/AEM.71.12.8344-8351.2005 VL - 71 IS - 12 SP - 8344-8351 SN - 1098-5336 ER - TY - JOUR TI - Comparison of sensory, microbiological, and biochemical parameters of microwave versus indirect UHT fluid skim milk during storage AU - Clare, DA AU - Bang, WS AU - Cartwright, G AU - Drake, MA AU - Coronel, P AU - Simunovic, J T2 - JOURNAL OF DAIRY SCIENCE AB - Shelf-stable milk could benefit from sensory quality improvement. Current methods of heating cause flavor and nutrient degradation through exposure to overheated thermal exchange surfaces. Rapid heating with microwaves followed by sudden cooling could reduce or eliminate this problem. The objectives for this study were focused on designing and implementing continuous microwave thermal processing of skim fluid milks (white and chocolate) to compare sensory, microbiological, and biochemical parameters with conventionally prepared, indirect UHT milks. All test products were aseptically packaged and stored at ambient temperature for 12 mo. Every 3 mo, samples were taken for microbiological testing, reactive sulfhydryl determinations, active enzyme analysis, instrumental viscosity readings, color measurements, and descriptive sensory evaluation. Microbiological plate counts were negative on all milks at each time point. Enzymatic assays showed that plasmin was inactivated by both heat treatments. 5,5'-dithio-bis(2-nitrobenzoic acid) analysis, a measure of reactive sulfhydryl (-SH-) groups, showed that the initial thiol content was not significantly different between the microwave-processed and UHT-treated milks. However, both heating methods resulted in an increased thiol level compared with conventionally pasteurized milk samples due to the higher temperatures attained. Sulfhydryl oxidase, a milk enzyme that catalyzes disulfide bond formation using a variety of protein substrates, retained activity following microwave processing, and decreased during storage. Viscosity values were essentially equivalent in microwave- and UHT-heated white skim milks. Sensory analyses established that UHT-treated milks were visibly darker, and exhibited higher caramelized and stale/fatty flavors with increased astringency compared with the microwave samples. Sweet aromatic flavor and sweet taste decreased during storage in both UHT and microwave milk products, whereas stale/fatty flavors increased over time. Sensory effects were more apparent in white milks than in chocolate varieties. These studies suggest that microwave technology may provide a useful alternative processing method for delivery of aseptic milk products that retain a long shelf life. DA - 2005/12// PY - 2005/12// DO - 10.3168/jds.S0022-0302(05)73103-9 VL - 88 IS - 12 SP - 4172-4182 SN - 1525-3198 KW - ultra-high temperature KW - microwave KW - sulfhydryl oxidase KW - sensory ER - TY - JOUR TI - Characterization of dried whey protein concentrate and isolate flavor AU - Whetstine, MEC AU - Croissant, AE AU - Drake, MA T2 - JOURNAL OF DAIRY SCIENCE AB - The flavor of whey protein concentrates (WPC 80) and whey protein isolates (WPI) was studied using instrumental and sensory techniques. Four WPC 80 and 4 WPI, less than 3 mo old, were collected in duplicate from 6 manufacturers in the United States. Samples were rehydrated and evaluated in duplicate by descriptive sensory analysis. Duplicate samples with internal standards were extracted with diethyl ether. Extracts were then distilled to remove nonvolatile material using high vacuum distillation. Volatile extracts were analyzed using gas chromatography/olfactometry with post peak intensity analysis and aroma extract dilution analysis. Compounds were identified by comparison of retention indices, odor properties, and gas chromatography/mass spectrometry against reference standards. Whey proteins exhibited sweet aromatic, cardboard/wet paper, animal/wet dog, soapy, brothy, cucumber, and cooked/milky flavors, along with the basic taste bitter, and the feeling factor astringency. Key volatile flavor compounds in WPC 80 and WPI were butanoic acid (cheesy), 2-acetyl-1-pyrroline (popcorn), 2-methyl-3-furanthiol (brothy/burnt), 2,5-dimethyl-4-hydroxy-3-(2H)-furanone (maple/spicy), 2-nonenal (fatty/old books), (E,Z)-2,6-nonadienal (cucumber), and (E,Z)-2,4-decadienal (fatty/oxidized). This baseline data on flavor and flavor sources in whey proteins will aid ongoing and future research and will help to identify the most appropriate whey ingredients to use to control or minimize flavor variability in whey enhanced products. DA - 2005/11// PY - 2005/11// DO - 10.3168/jds.S0022-0302(05)73068-X VL - 88 IS - 11 SP - 3826-3839 SN - 1525-3198 KW - whey protein concentrate KW - whey protein isolate KW - flavor ER - TY - JOUR TI - Thermal resistance of Salmonella enterica serotypes, Listeria monocytogenes, and Staphylococcus aureus in high solids liquid egg mixes AU - Li, X AU - Sheldon, BW AU - Ball, HR T2 - JOURNAL OF FOOD PROTECTION AB - Decimal reduction times (D-values) were determined for Salmonella enterica serotypes, Listeria monocytogenes, and Staphylococcus aureus in two high solids egg mixes designated A and B (water activity [a(w)] = 0.76 and 0.82; solids = 53.12 and 52.63%; pH = 5.09 and 5.29; viscosity = 183 and 119 centipoise/s, respectively) using a low-volume (0.06 ml) sealed glass capillary tube procedure. For Salmonella, D-values ranged from 0.035 (70 degrees C) to 0.193 min (64 degrees C) in product A and from 0.048 to 0.193 min in product B. For Listeria, D-values ranged from 0.133 (70 degrees C) to 0.440 min (64 degrees C) in product A and from 0.074 to 0.364 min in product B. For Staphylococcus, D-values ranged from 0.332 (70 degrees C) to 1.304 min (64 degrees C) in product A and from 0.428 to 1.768 min in product B. For Listeria, the D-values of all heating temperatures were significantly higher (P < 0.01) in product A than in product B. The similar trend was also observed for Salmonella and Staphylococcus but only at 66 degrees C for Salmonella and 64 degrees C for Staphylococcus. Greater temperature dependence was observed for Salmonella inactivation in the low a(w) and low pH product (A), while the product (B) with the higher a(w) and pH had greater temperature dependence for Listeria. Compared across both egg mixes and all heating temperatures, the Staphylococcus strains were from 6.2 to 11.7 times more heat resistant than S. enterica serotypes and from 2.2 to 7.5 times more heat resistant than L. monocytogenes. DA - 2005/4// PY - 2005/4// DO - 10.4315/0362-028X-68.4.703 VL - 68 IS - 4 SP - 703-710 SN - 1944-9097 ER - TY - JOUR TI - Estimation of most probable number Salmonella populations on commercial North Carolina turkey farms AU - Santos, FBO AU - Li, X AU - Payne, JB AU - Sheldon, BW T2 - JOURNAL OF APPLIED POULTRY RESEARCH AB - Salmonellae are one of the primary causes of human gastroenteritis in the United States. Although there are many foods that may be contaminated with Salmonella, poultry products are one of the major vehicles for transmitting this organism to humans. However, the national incidence of poultry product contamination with Salmonella has declined since adoption of the Hazard Analysis and Critical Control Point (HACCP) food safety program. Further reductions in carcass contamination may require other approaches such as the adoption of on-farm pathogen reduction strategies. In this study Salmonella prevalence and populations from fresh excreta and litter composite samples taken from 12 commercial turkey farms were enumerated using the most probable number (MPN) method and compared as a function of farm, season (summer and winter), and bird age (3 vs. 19 wk). Moreover, litter pH, temperature, moisture content, water activity, and ammonia levels were monitored. All farms were Salmonella positive for at least one season, and populations ranged from <1 log MPN/g to >5.3 log MPN/g. Of the 48 separate fecal and litter composite samples analyzed, 70 and 79% were Salmonella-positive, respectively. Although the MPN enumeration method is much more labor intensive and costly than the prevalence method, it yields estimates of Salmonella populations instead of merely indications of presence or absence of the organism. Moreover, our findings demonstrated that the MPN method is significantly more sensitive compared with the prevalence procedure (for fecal samples). This study also demonstrated that Salmonella can be present at high populations during turkey production and that their populations and prevalence were significantly impacted by flock age (litter) and season by farm interactions (fecal). Furthermore, litter Salmonella populations appear to be associated with the interrelated parameters of litter pH, ammonia and moisture content. DA - 2005/// PY - 2005/// DO - 10.1093/japr/14.4.700 VL - 14 IS - 4 SP - 700-708 SN - 1537-0437 KW - turkey KW - farm KW - Salmonella population KW - litter KW - feces ER - TY - JOUR TI - Enzymatic and microbiological inhibitory activity in eggshell membranes as influenced by layer strains and age and storage variables AU - Ahlborn, G AU - Sheldon, BW T2 - POULTRY SCIENCE AB - Eggshell membranes (ESM) have been shown to exhibit antibacterial activity. The purpose of this study was to evaluate the enzymatic and biological [decimal reduction times (D-values)] activities of ESM as a function of bird breed, age, and ESM stabilization treatments. Younger White Leghorn (WL) hens produced ESM with 28% higher lysozyme activity than Rhode Island Red (RIR) layers. In contrast, older WL layers produced ESM with 17% less lysozyme activity than ESM from RIR layers. Similarly, beta-N-acetylglucosaminidase (beta-NAGase) ESM activities differed by hen age within breeds with younger hens yielding 14 to 16% more enzyme activity. D54 degrees C-values of Salmonella Typhimurium cells preexposed to WL ESM did not differ as a function of bird age (33, 50, and 81 wk). The ESM Lysozyme and beta-NAGase activities varied somewhat over a 6-mo storage study after treatment with 1 of 5 stabilization methods [i.e., storage at 4 degrees C, -20 degrees C, or ambient air storage after freeze drying, air drying (23 degrees C), or forced-air drying (50 degrees C)]. Both air and forced-air drying yielded significant reductions in beta-NAGase and lysozyme ESM activity (ca 12 to 30%) after the initial 24 h and then remained fairly stable during the extended storage. Freeze-dried samples retained the most enzymatic activity (95%) throughout the 6-mo trial, whereas refrigerated ESM lost 20 and 18% of the beta-NAGase and lysozyme activities, respectively. Frozen ESM lost 22% of the beta-NAGase activity, whereas lysozyme was nearly unaffected after 6 mo. The ESM biological activities against S. Typhimurium were not adversely impacted by layer breed or age. No significant loss in biological activity of ESM was detected 24 h after processing or after 6 mo of storage for refrigerated, frozen, and freeze-dried membranes, whereas significant reductions were observed for air- and heat-dried ESM. These findings demonstrate that ESM enzyme and biological activities are relatively constant across layer breeds and over extended storage. Based on these and other findings, ESM may have potential commercial value as a processing adjuvant in food and pharmaceutical product applications. DA - 2005/12// PY - 2005/12// DO - 10.1093/ps/84.12.1935 VL - 84 IS - 12 SP - 1935-1941 SN - 1525-3171 KW - eggshell membrane KW - beta-N-acetylglucosaminidase KW - lysozyme KW - stability KW - inhibitory activity ER - TY - JOUR TI - Effects of the bioregulators aminoethoxyvinylglycine and ethephon on brix, carbohydrate, acid, and mineral concentrations in 'Scarletspur Delicious' apple juice AU - Drake, S. R. AU - Eisele, T. A. AU - Elfving, D. C. AU - Drake, M. A. AU - Drake, S. L. AU - Visser, D. B. T2 - HortScience DA - 2005/// PY - 2005/// VL - 40 IS - 5 SP - 1421-1424 ER - TY - JOUR TI - Effect of 3 months frozen-storage on organic acid contents and sensory properties, and their correlations in soft goat milk cheese AU - Park, YW AU - Drake, MA T2 - SMALL RUMINANT RESEARCH AB - Organic acid concentrations and sensory properties, and correlations between the two parameters for soft goat milk cheeses were evaluated throughout 3 months of frozen-storage. Three different lots of commercial soft goat cheeses were purchased, and subdivided into three equal portions. One portion was stored at 4 °C as the non-frozen control and the other two were immediately frozen (−20 °C) for 0 and 3 months, then subsequently thawed the next day at 4 °C and stored at 4 °C for 0, 14 and 28 days. Organic acids were analyzed using a HPLC (Hewlett Packard; LC-1100 Series). Descriptive sensory properties were evaluated by a trained panel, and flavors and tastes were scored on a 10-point Spectrum™ intensity scale. Results showed that tartaric, citric, uric and propionic acids in the soft goat cheese tended to increase after 3 months frozen-storage, while formic and malic acids decreased, and pyruvic acid was absent. Initial sensory properties of goat cheeses through 3 months frozen-storage were not changed in comparison of non-frozen fresh cheeses. However, cooked/milky, whey, milkfat, diacetyl and sweet, sour, and salty tastes diminished with prolonged refrigerated aging time for all frozen-storage regimes, while brothy, yeasty, and oxidized flavors increased. Some correlations (r) between organic acids and sensory properties were observed, including r-values between tartaric acid and goaty/waxy flavor, formic acid and sour taste, malic acid and cooked milky flavor, acetic acid and saltiness, citric acid and whey flavor, propionic and brothy or oxidized flavor, and some unknown acids with milk fat lactone flavor. DA - 2005/6// PY - 2005/6// DO - 10.1016/j.smallrumres.2004.12.001 VL - 58 IS - 3 SP - 291-298 SN - 0921-4488 KW - goat cheese KW - organic acids KW - sensory score KW - correlations ER - TY - JOUR TI - The effects of acidulant type on the rheological properties of beta-lactoglobulin gels and powders derived from these gels AU - Resch, JJ AU - Daubert, CR AU - Foegeding, EA T2 - FOOD HYDROCOLLOIDS AB - Heat-induced beta-lactoglobulin (β-Lg) gels and instantly-thickening protein powders derived from these gels were rheologically characterized to identify how acid selection and pH adjustment impact whey protein gelation and derived powder properties. An established procedure for the production of an instant-thickening whey protein ingredient, consisting of protein hydration, pH adjustment to 3.35, thermal gelation at 80 °C, and drying, was applied to β-Lg. Hydrochloric, lactic, citric, and phosphoric acids were evaluated in the critical pH adjustment step. Acidulant selection clearly impacted β-Lg gelation and derived powder properties. Ion specific effects were in general agreement with classical Hofmeister series behavior. Maximum viscosity and water holding were observed in the ingredients derived from the strong, translucent gels created in systems utilizing lactic and hydrochloric acids. Use of citric acid resulted in a brittle, opaque coagulum which created an ingredient with very poor thickening functionality. Protein solutions treated with phosphoric acid were most resistant to gelation at 80 °C and led to limited thickening ability of the derived powder. Acidulant selection is an important processing parameter that may be manipulated to modify β-Lg gelation and the functional properties of derived thickening ingredients. DA - 2005/9// PY - 2005/9// DO - 10.1016/j.foodhyd.2004.10.034 VL - 19 IS - 5 SP - 851-860 SN - 1873-7137 KW - beta-lactoglobulin KW - gelation KW - acidulants KW - rheology KW - denaturation KW - Hofmeister series ER - TY - JOUR TI - Sequence analysis of the Lactobacillus plantarum bacteriophage Phi JL-1 AU - Lu, Z AU - Altermann, E AU - Breidt, F AU - Predki, P AU - Fleming, HP AU - Klaenhammer, TR T2 - GENE AB - The complete genomic sequence of a Lactobacillus plantarum virulent phage PhiJL-1 was determined. The phage possesses a linear, double-stranded, DNA genome consisting of 36,677 bp with a G+C content of 39.36%. A total of 52 possible open reading frames (ORFs) were identified. According to N-terminal amino acid sequencing and bioinformatic analyses, proven or putative functions were assigned to 21 ORFs (41%), including 5 structural protein genes. The PhiJL-1 genome shows functionally related genes clustered together in a genome structure composed of modules for DNA replication, DNA packaging, head and tail morphogenesis, and lysis. This type of modular genomic organization was similar to several other phages infecting lactic acid bacteria. The structural gene maps revealed that the order of the head and tail genes is highly conserved among the genomes of several Siphoviridae phages, allowing the assignment of probable functions to certain uncharacterized ORFs from phage PhiJL-1 and other Siphoviridae phages. DA - 2005/3/28/ PY - 2005/3/28/ DO - 10.1016/j.gene.2004.12.052 VL - 348 SP - 45-54 SN - 1879-0038 KW - bacteriophage KW - Phi JL-1 KW - sequence analysis KW - structural proteins KW - Lactobacillus plantarum ER - TY - JOUR TI - Securing the food chain: The 2000-04 southeastern US fresh produce food safety train-the-trainer program AU - Osborne, D. J. AU - Sanders, D. C. AU - Ward, D. R. AU - Rushing, J. W. T2 - HortTechnology DA - 2005/// PY - 2005/// VL - 15 IS - 4 SP - 875-879 ER - TY - JOUR TI - PathwayVoyager: pathway mapping using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database AU - Altermann, E. AU - Klaenhammer, T. R. T2 - BMC Genomics DA - 2005/// PY - 2005/// VL - 6 ER - TY - JOUR TI - Marker-free chromosomal integration of the manganese superoxide dismutase gene (sodA) from Streptococcus thermophilus into Lactobacillus gasseri AU - Bruno-Barcena, JM AU - Azcarate-Peril, MA AU - Klaenhammer, TR AU - Hassan, HM T2 - FEMS MICROBIOLOGY LETTERS AB - A strategy for functional gene replacement in the chromosome of Lactobacillus gasseri is described. The phospho-β-galactosidase II gene (lacII) was functionally replaced by the manganese superoxide dismutase (MnSOD) gene (sodA) from Streptococcus thermophilus, by adapting the insertional inactivation method described for lactobacilli [Russell, W.M. and Klaenhammer, T.R. 2001 Efficient system for directed integration into the Lactobacillus acidophilus and Lactobacillus gasseri chromosomes via homologous recombination. Appl. Environ. Microbiol. 67, 4361–4364]. L. gasseri carrying the heterologous sodA gene grew on lactose as efficiently as the wild-type parent. An active MnSOD was expressed in the transgenic strain, and the enzyme migrated on PAGE-SOD activity gels to the same position as that of MnSOD from S. thermophilus. The expression of MnSOD from a single copy of sodA integrated in the chromosome of L. gasseri provided enhanced tolerance to hydrogen peroxide, and extended the viability of carbon/energy starved cultures stored at 25 °C. This is the first report showing the successful utilization of the pORI plasmids system to generate marker-free gene integration in L. gasseri strains. DA - 2005/5/1/ PY - 2005/5/1/ DO - 10.1016/j.femsle.2005.03.044 VL - 246 IS - 1 SP - 91-101 SN - 1574-6968 KW - functional gene replacement KW - manganese superoxide dismutase KW - oxidative stress KW - Lactobacillus gasseri KW - lactic acid bacteria KW - probiotics ER - TY - JOUR TI - Influence of flavor variability in skim milk powder on consumer acceptability of ingredient applications AU - Caudle, AD AU - Yoon, Y AU - Drake, M T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT Flavor variability in skim milk powder (SMP) has been documented by descriptive sensory analysis and instrumental analysis. However, research has not addressed how or if SMP flavor variability impacts consumer acceptance of ingredient applications. Twenty reconstituted low‐heat SMPs were screened using a previously established defined sensory language. Two SMPs free of off‐flavors (flavor similar to fresh fluid skim milk) and 2 SMPs exhibiting off‐flavors (exhibiting flavors not found in fluid skim milk) were selected for further study. Volatile compounds were determined using solid phase microextraction (SPME) with gas chromatography‐mass spectrometry (GC‐MS). Each SMP was subsequently directly reconstituted or incorporated into standard formulas for vanilla ice cream, strawberry yogurt, hot cocoa mix, and white chocolate bars. Consumer acceptance testing was conducted. Descriptive panelists documented sweet aromatic and cooked flavors in the fresh‐flavored SMP and these flavors as well as fatty/fryer oil and animal‐like flavors in the off‐flavored SMP. Concurrently, instrumental volatile analysis revealed higher relative abundances of lipid oxidation compounds in the off‐flavored SMP. Consumer acceptance scores were lower for the off‐flavored SMP than for the fresh‐flavored SMP when evaluated directly reconstituted ( P < 0.05) and for ingredient applications made using off‐flavored SMP ( P < 0.05). Off‐flavors in SMP documented by descriptive analysis and trained panelists can carry through into ingredient applications with SMP and negatively affect consumer acceptability. DA - 2005/9// PY - 2005/9// DO - 10.1111/j.1365-2621.2005.tb11487.x VL - 70 IS - 7 SP - S427-S431 SN - 1750-3841 KW - skim milkpowder KW - flavor KW - ingredient applications ER - TY - JOUR TI - Fractionation and characterization of cysteine proteinase inhibitor from chicken plasma AU - Rawdkuen, S AU - Benjakul, S AU - Visessanguan, W AU - Lanier, TC T2 - JOURNAL OF FOOD BIOCHEMISTRY AB - The fractionation of cysteine proteinase inhibitor (CPI) from chicken blood plasma was carried out using polyethylene glycol-4000 or ammonium sulfate (AS) precipitation. The addition of PEG at the level of 400 g/L, on the basis of the original volume of plasma protein, was more effective to fractionate CPI than using AS. CPI in the PEG fraction had a molecular weight of about 46 kDa with intramolecular disulfide bond. CPI containing fraction was colorless and had no absorbance in the range of 700–360 nm. The fraction was stable in the temperature range of 40–90C for 10 min and still retained high inhibitory activity toward papain after incubation at 90C for 60 min. NaCl, at 0–3.0% concentration, did not affect the inhibitory activity of the CPI containing fraction. The fraction was stable at pH 8.0, and the minimal inhibitory activity against papain was found at pH 5–6. Therefore, PEG fractionation effectively isolated the CPI from chicken plasma. DA - 2005/10// PY - 2005/10// DO - 10.1111/j.1745-4514.2005.00027.x VL - 29 IS - 5 SP - 486-503 SN - 1745-4514 ER - TY - JOUR TI - A model for temperature and moisture distribution during continuous microwave drying AU - Boldor, D. AU - Sanders, T. H. AU - Swartzel, K. R. AU - Farkas, B. E. T2 - Journal of Food Process Engineering AB - ABSTRACT A heat and mass transfer model of continuous drying of farmer stock (in‐shell, uncured) peanuts ( Arachis hypogaea L.) in a planar microwave applicator was developed and investigated. Transport phenomena equations previously developed for batch‐type microwave drying were successfully adapted to account for the spatial variation of the electric field inside the applicator. The theoretical equations developed, together with experimental methods, were used to determine the effect of microwave power level and dielectric properties on the temperature profiles and reduction in peanuts’ moisture content (mc). The temperature profiles from the solution of these equations matched the experimental ones determined using fiber optic temperature probes inserted into drying peanut pods. An exact theoretical determination of mc reduction during microwave drying was not possible due to the dependence of dielectric properties on mc. The surface temperature distribution of the peanut bed measured using infrared pyrometry was well correlated with internal temperature profiles. DA - 2005/// PY - 2005/// DO - 10.1111/j.1745-4530.2005.00387.x VL - 28 IS - 1 SP - 68-87 ER - TY - JOUR TI - Production and sensory characterization of a bitter peptide from beta-casein AU - Singh, TK AU - Young, ND AU - Drake, M AU - Cadwallader, KR T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - Peptide β-casein fragment 193-209 (β-CN f193-209) was isolated and purified for detailed sensory analysis in different matrices. The purity of the peptide was >98%. The mass of the peptide was 1882.51 Da, which coincided with the expected mass of β-CN f193-209. N-Terminal analysis confirmed that the peptide started at residue 193 on the published sequence of β-casein. Detection thresholds were 0.03, 0.06, and 0.63% (w/w) for water, milk, and cheese, respectively. Descriptive sensory analysis confirmed that the peptide exhibited a bitter taste, which increased with increasing concentrations, with minimal other flavors or tastes detected. The β-CN f193-209 can contribute to bitterness in cheeses. Keywords: Caseins; peptide; bitter taste; caffeine; quinine sulfate; sensory threshold analysis; descriptive sensory analysis DA - 2005/2/23/ PY - 2005/2/23/ DO - 10.1021/jf049058d VL - 53 IS - 4 SP - 1185-1189 SN - 1520-5118 KW - caseins KW - peptide KW - bitter taste KW - caffeine KW - quinine sulfate KW - sensory threshold analysis KW - descriptive sensory analysis ER - TY - JOUR TI - Isolation and selection of lactic acid bacteria as biocontrol agents for nonacidified, refrigerated pickles AU - Reina, LD AU - Breidt, F AU - Fleming, HP AU - Kathariou, S T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: A nonacidified, deli-type pickle product was used as a model system to study the potential use of biocontrol as a means to prevent the growth of pathogens in minimally processed fruits and vegetables (MPFV). Fresh pickling cucumbers were blanched and brined with sterile spices and garlic oil. The product was stored at 5 °C for 3 wk and then transferred to various abuse temperatures (16 °C, 25 °C, 30 °C). Lactic acid bacteria (LAB) were isolated and characterized as potential biocontrol agents, and the isolates were tested for bacteriocin-like activity. A total of 118 LAB isolates were obtained. Among the LAB identified were species of Lactococcus, Leuconostoc, Lactobacillus, Weissella, and Enterococcus. Three isolates showed transient bacteriocin activity against—Listeria monocytogenes, and 7 isolates (Lactococcus) had bacteriocin-like activity against other LAB. Although it did not produce a bacteriocin, a Lactobacillus curvatus isolate (LR55) was found to have desirable characteristics for use as a biocontrol (competitive exclusion) culture to enhance the safety of nonacidified deli-type pickles. DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb09050.x VL - 70 IS - 1 SP - M7-M11 SN - 1750-3841 KW - lactic acid bacteria KW - minimally processed vegetables KW - bacteriocin KW - biocontrol ER - TY - JOUR TI - In-package pasteurization combined with biocide-impregnated films to inhibit Listeria monocytogenes and Salmonella typhimurium in Turkey bologna AU - McCormick, KE AU - Han, IY AU - Acton, JC AU - Sheldon, BW AU - Dawson, PL T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: The inhibitory effects of in-package pasteurization (3–5D, decimal reduction times) combined with a nisin (7%, w/w) containing wheat gluten film were tested over an 8-wk storage period against Listeria monocytogenes and Salmonella Typhimurium populations inoculated on refrigerated bologna. Bologna slices subjected to the in-package pasteurization process reducedL. monocytogenes populations 3.8- to 7.0-log colony-forming units (CFU)/g, and the remaining population fluctuated between 1.2- and 38-log CFU/g over the 2-mo storage period. S. Typhimurium was reduced 5.7- to 7.3-log CFU/g, and the remaining population progressively declined from 100 to <10 CFU/g over 2 mo of storage. The wheat gluten film containing nisin was effective in reducing the population of L. monocytogenes (2.75-log reduction with pasteurization; 1-log reduction without pasteurization), but was not effective against S. Typhimurium (<1-log reduction). Combining both treatments significantly reduced the L. monocytogenes populations and prevented outgrowth over the 2-mo storage period but provided no added inhibitory effect against S. Typhimurium compared with only pasteurization. DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb09046.x VL - 70 IS - 1 SP - M52-M57 SN - 1750-3841 KW - in-package pasteurization KW - antimicrobial films KW - bologna KW - Listeria monocytogenes KW - Salmonella Typhimurium ER - TY - JOUR TI - Detection and identification of histamine-producing bacteria associated with harvesting and processing mahimahi and yellowfin tuna AU - Allen, DG AU - Green, DP AU - Bolton, GE AU - Jaykus, LA AU - Cope, WG T2 - JOURNAL OF FOOD PROTECTION AB - Histamine poisoning is one of the most common chemically induced seafoodborne illnesses reported in the United States today. The causative agents are biogenic amines, commonly produced by gram-negative bacteria. The purpose of this study was to detect and identify histamine-producing bacteria associated with standard industry practices during the harvesting, receiving, and processing of mahimahi and yellowfin tuna in North Carolina. Twenty-nine composite samples were obtained from 18 mahimahi and 11 yellowfin tuna and analyzed for their histamine content. No sample analyzed exceeded 2 ppm histamine, the lower detection limit. Composite fish muscle and environmental samples were screened (n = 386) for the presence of histamine-producing bacteria. Twenty-six percent (145) of 549 isolates selected on the basis of their morphological characteristics tested positive on Niven's media. Sixty-three Niven-positive isolates were gram negative, and 58 were gram positive. Of the 43 isolates tested further, 5 were confirmed as histamine producers, and all 5 produced at low levels (< 250 ppm in 48 h at > 15 degrees C). Three gram-negative and two gram-positive isolates were identified as Enterobacter cloacae and Staphylococcus kloosii, respectively. This study revealed that gram-negative bacteria might not be solely responsible for histamine production in at-risk fish. The confirmation of histamine-producing bacteria demonstrates the potential risk for histamine production. However, no detectable levels were found in the composite fish muscle samples analyzed even though 60% of the yellowfin tuna harvested did not meet the U.S. Food and Drug Administration's regulatory hazard analysis critical control point guidelines for temperature reduction. Therefore, no seafood safety risks were found under the standard industry practices observed in this study. DA - 2005/8// PY - 2005/8// DO - 10.4315/0362-028X-68.8.1676 VL - 68 IS - 8 SP - 1676-1682 SN - 1944-9097 ER - TY - JOUR TI - Rapid determination of moisture/solids and fat in dairy products by microwave and nuclear magnetic resonance analysis AU - Cartwright, G. AU - Mcmanus, B. H. AU - Leffler, T. P. AU - Moser, C. R. T2 - Journal of AOAC International DA - 2005/// PY - 2005/// VL - 88 IS - 1 SP - 107-120 ER - TY - JOUR TI - Inactivation of penicillin G in milk using hydrogen peroxide AU - Hanway, WH AU - Hansen, AP AU - Anderson, KL AU - Lyman, RL AU - Rushing, JE T2 - JOURNAL OF DAIRY SCIENCE AB - Milk antibiotic residues have been a public concern in recent years. The Grade A Pasteurized Milk Ordinance mandates that raw Grade A milk will test negative for beta-lactam antibiotic residues before processing. The purpose of this research was to investigate the ability of various levels of peroxide and heat to inactivate penicillin G in raw milk. Whole milk spiked to a mean of 436 +/- 15.1 (standard error of the mean) ppb of potassium penicillin G was treated with hydrogen peroxide at levels of 0.0, 0.09, 0.17, and 0.34%. Samples at each peroxide level (n = 6 per treatment) were treated as follows: 1) incubated at 54.4 degrees C for 3 h, 2) pasteurized at 62.8 degrees C for 30 min, 3) incubated and pasteurized as in treatments 1 and 2, or 4) received no further treatment. A beta-lactam competitive microbial receptor assay was used for quantification of penicillin G. Concentrations of penicillin in selected samples were determined by HPLC for a comparison of test methods. Treatments were evaluated relative to their ability to reduce milk penicillin G levels to below the safe level of 5 ppb. The 0.09% hydrogen peroxide level was ineffective for all treatments. Hydrogen peroxide at 0.17% lowered the mean penicillin G (+/- SEM) from 436 +/- 15.1 to 6 +/- 1.49 ppb using the incubated and pasteurized heat treatment. The 0.34% concentration of hydrogen peroxide was the most effective, inactivating penicillin G to a level well below the safe level of 5 ppb with the pasteurized heat treatment, with or without incubation. DA - 2005/2// PY - 2005/2// DO - 10.3168/jds.S0022-0302(05)72707-7 VL - 88 IS - 2 SP - 466-469 SN - 1525-3198 KW - milk KW - penicillin KW - antibiotic KW - hydrogen peroxide ER - TY - JOUR TI - Genomic features of lactic acid bacteria effecting bioprocessing and health AU - Klaenhammer, TR AU - Barrangou, R AU - Buck, BL AU - Azcarate-Peril, MA AU - Altermann, E T2 - FEMS MICROBIOLOGY REVIEWS AB - The lactic acid bacteria are a functionally related group of organisms known primarily for their bioprocessing roles in food and beverages. More recently, selected members of the lactic acid bacteria have been implicated in a number of probiotic roles that impact general health and well-being. Genomic analyses of multiple members of the lactic acid bacteria, at the genus, species, and strain level, have now elucidated many genetic features that direct their fermentative and probiotic roles. This information is providing an important platform for understanding core mechanisms that control and regulate bacterial growth, survival, signaling, and fermentative processes and, in some cases, potentially underlying probiotic activities within complex microbial and host ecosystems. DA - 2005/8// PY - 2005/8// DO - 10.1016/j.femsre.2005.04.007 VL - 29 IS - 3 SP - 393-409 SN - 1574-6976 KW - lactic acid bacteria KW - genomics KW - bioprocessing KW - probiotics KW - comparative genomics KW - functional genomics ER - TY - JOUR TI - Foaming and interfacial properties of hydrolyzed beta-lactoglobulin AU - Davis, JP AU - Doucet, D AU - Foegeding, EA T2 - JOURNAL OF COLLOID AND INTERFACE SCIENCE AB - beta-lactoglobulin (beta-lg) was hydrolyzed with three different proteases and subsequently evaluated for its foaming potential. Foam yield stress (tau0) was the primary variable of interest. Two heat treatments designed to inactivate the enzymes, 75 degrees C/30 min and 90 degrees C/15 min, were also investigated for their effects on foam tau0. Adsorption rates and dilatational rheological tests at a model air/water interface aided data interpretation. All unheated hydrolysates improved foam tau0 as compared to unhydrolyzed beta-lg, with those of pepsin and Alcalase 2.4L(R) being superior to trypsin. Heat inactivation negatively impacted foam tau0, although heating at 75 degrees C/30 min better preserved this parameter than heating at 90 degrees C/15 min. All hydrolysates adsorbed more rapidly at the air/water interface than unhydrolyzed beta-lg, as evidenced by their capacity to lower the interfacial tension. A previously observed relationship between interfacial dilatational elasticity (E') and tau0 was generally confirmed for these hydrolysates. Additionally, the three hydrolysates imparting the highest tau0 not only had high values of E' (approximately twice that of unhydrolyzed beta-lg), they also had very low phase angles (essentially zero). This highly elastic interfacial state is presumed to improve foam tau0 indirectly by improving foam stability and directly by imparting resistance to interfacial deformation. DA - 2005/8/15/ PY - 2005/8/15/ DO - 10.1016/j.jcis.2005.03.002 VL - 288 IS - 2 SP - 412-422 SN - 1095-7103 KW - dilatational modulus KW - dilatational elasticity KW - adsorption KW - interfacial rheology KW - beta-lactoglobulin KW - peptide KW - hydrolysate KW - foam KW - yield stress KW - whey protein ER - TY - JOUR TI - Effect of food matrix and cell growth on PCR-based detection of Escherichia coli O157 : H7 in ground beef AU - Taylor, TM AU - Elhanafi, D AU - Drake, M AU - Jaykus, LA T2 - JOURNAL OF FOOD PROTECTION AB - The purpose of this work was (i) to investigate the feasibility of a previously reported upstream processing method for PCR template preparation to facilitate the detection of Escherichia coli O157:H7 from ground beef and (ii) to assess the impact of cell growth (no growth in the matrix versus growth in the matrix) on molecular detection limits. Two food matrices (autoclaved and raw ground beef) were evaluated in all studies. For no-growth experiments, 10-g meat samples were inoculated with 10(2) to 10(7) CFU/g E. coli O157:H7 and then homogenized. The homogenates were processed to remove large particulates and inhibitors using a two-phase upstream processing method consisting of two sequential centrifugation steps, the second of which used titanous hydroxide to facilitate bacterial immobilization. After upstream processing, sample concentrates were extracted for DNA isolation and amplified by PCR. For growth experiments, 10-g meat samples were inoculated at 1 CFU of E. coli O157:H7 per gram, allowed to grow to 10(2) to 10(7) CFU/g, and then processed for PCR assay. Cell recoveries after upstream processing ranged from 15.9 to 77.6% and were not facilitated by the use of titanous hydroxide, as compared with a saline control (P > 0.05). Bacterial cell recovery and PCR detection limits were similar when comparing autoclaved ground beef and raw ground beef, but cell recoveries were highly variable for raw ground beef samples in which E. coli O157:H7 cells were allowed to grow before processing for detection. Overall, PCR detection limits approximated 10(3) CFU/g of ground beef for all treatments. These results indicate that use of model food systems may not always provide an accurate replication of real-world conditions when evaluating PCR detection limits. DA - 2005/2// PY - 2005/2// DO - 10.4315/0362-028X-68.2.225 VL - 68 IS - 2 SP - 225-232 SN - 1944-9097 ER - TY - JOUR TI - Determination of 5-log pathogen reduction times for heat-processed, acidified vegetable brines AU - Breidt, F AU - Hayes, JS AU - Osborne, JA AU - McFeeters, RF T2 - JOURNAL OF FOOD PROTECTION AB - Recent outbreaks of acid-resistant food pathogens in acid foods, including apple cider and orange juice, have raised concerns about the safety of acidified vegetable products. We determined pasteurization times and temperatures needed to assure a 5-log reduction in the numbers of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella strains in acidified cucumber pickle brines. Cocktails of five strains of each pathogen were (separately) used for heat-inactivation studies between 50 and 60 degrees C in brines that had an equilibrated pH value of 4.1. Salmonella strains were found to be less heat resistant than E. coli O157:H7 or L. monocytogenes strains. The nonlinear killing curves generated during these studies were modeled using a Weibull function. We found no significant difference in the heat-killing data for E. coli O157:H7 and L. monocytogenes (P = 0.9709). The predicted 5-log reduction times for E. coli O157:H7 and L. monocytogenes were found to fit an exponential decay function. These data were used to estimate minimum pasteurization times and temperatures needed to ensure safe processing of acidified pickle products and show that current industry pasteurization practices offer a significant margin of safety. DA - 2005/2// PY - 2005/2// DO - 10.4315/0362-028X-68.2.305 VL - 68 IS - 2 SP - 305-310 SN - 0362-028X ER - TY - JOUR TI - Descriptive analysis and US consumer acceptability of peanuts from different origins AU - Young, ND AU - Sanders, TH AU - Drake, MA AU - Osborne, J AU - Civille, GV T2 - FOOD QUALITY AND PREFERENCE AB - The objective of this study was to evaluate descriptive and consumer flavor responses to peanuts (Arachis hypogaea, runner type) from different production origins: United States, China, and Argentina. Twenty, 25-lb samples from lots exported from each country (total=60) were randomly selected. After roasting, peanuts were evaluated using descriptive sensory analysis. Six samples from each origin, which covered the sensory space of all samples from that origin were selected for consumer testing in the United States. Consumers (n=100) evaluated peanuts for overall liking and the strength/intensity for liking of: color, flavor and texture attributes using a nine-point hedonic scale. Descriptive sensory profiles, specific for the different origins, were observed (p<0.05). Consumer scores for overall liking were United States>China>Argentina, respectively. Overall and flavor liking exhibited strong correlation with strength/intensity for liking characteristics of many of the attributes studied (p<0.05). This study demonstrated that production origin impacts descriptive sensory attribute intensity and consumer preference of roasted peanuts. DA - 2005/1// PY - 2005/1// DO - 10.1016/j.foodqual.2003.12.006 VL - 16 IS - 1 SP - 37-43 SN - 0950-3293 KW - peanut flavor KW - sensory analysis KW - descriptive analysis KW - consumer evaluation ER - TY - JOUR TI - A simple method for the direct detection of Salmonella and Escherichia coli O157 : H7 from raw alfalfa sprouts and spent irrigation water using PCR AU - Johnston, LM AU - Elhanafi, D AU - Drake, M AU - Jaykus, LA T2 - JOURNAL OF FOOD PROTECTION AB - The U.S. Food and Drug Administration recognizes that raw seed sprouts are an important cause of foodborne disease and is now recommending that either spent irrigation water or final product be screened for Salmonella and Escherichia coli O157:H7 as a means of assuring the safety of product intended for consumption. In an effort to streamline such testing efforts, a simple method to preconcentrate pathogens from sprouts and spent irrigation water was investigated to facilitate the direct (without prior cultural enrichment) detection of pathogens using the PCR technique. Alfalfa sprouts and spent irrigation water were seeded with Salmonella enterica serovar Typhimurium and E. coli O157:H7 at 10(-1) to 106 CFU/g or CFU/ml, respectively. Samples were blended (sprouts only) and then centrifuged at high speed to sediment the total bacterial population. The precipitate was processed for DNA isolation, PCR amplification, and amplicon confirmation by Southern hybridization. Mean pathogen recoveries after centrifugation ranged from 96 to 99% for both pathogens in both matrices. Using primers targeting the invA gene for Salmonella Typhimurium and the stx genes of E. coli O157:H7, it was possible to detect both pathogens in alfalfa sprouts at seeding concentrations as low as 10 CFU/g. PCR detection limits for both pathogens from spent irrigation water were 10(-1) CFU/ml, the equivalent of 100 CFU/liter of water. Because spent irrigation water is constitutionally simple, it is particularly well suited for bacterial concentration by simple centrifugation steps. In this study, progress was made toward development of a rapid, inexpensive, and sensitive method for the detection of sprout-associated pathogens that is relevant to current industrial practices and needs. DA - 2005/11// PY - 2005/11// DO - 10.4315/0362-028X-68.11.2256 VL - 68 IS - 11 SP - 2256-2263 SN - 1944-9097 ER - TY - JOUR TI - Modulation of the microbial ecology of the human colon by probiotics, prebiotics and synbiotics to enhance human health: An overview of enabling science and potential applications AU - Rastall, RA AU - Gibson, GR AU - Gill, HS AU - Guarner, F AU - Klaenhammer, TR AU - Pot, B AU - Reid, G AU - Rowland, IR AU - Sanders, ME T2 - FEMS MICROBIOLOGY ECOLOGY AB - The application of probiotics and prebiotics to the manipulation of the microbial ecology of the human colon has recently seen many scientific advances. The sequencing of probiotic genomes is providing a wealth of new information on the biology of these microorganisms. In addition, we are learning more about the interactions of probiotics with human cells and with pathogenic bacteria. An alternative means of modulating the colonic microbial community is by the use of prebiotic oligosaccharides. Increasing knowledge of the metabolism of prebiotics by probiotics is allowing us to consider specifically targeting such dietary intervention tools at specific population groups and specific disease states. DA - 2005/4/1/ PY - 2005/4/1/ DO - 10.1016/j.femsec.2005.01.003 VL - 52 IS - 2 SP - 145-152 SN - 1574-6941 KW - probiotics KW - prebiotics KW - synbiotics KW - colonic microbiota ER - TY - JOUR TI - Heat transfer and microbial kinetics modeling to determine the location of microorganisms within cucumber fruit AU - Mattos, FR AU - Fasina, OO AU - Reina, LD AU - Fleming, HP AU - Breidt, F AU - Damasceno, GS AU - Passos, FV T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: Microbiological and modeling (combined heat transfer and microbial kinetic equations [HTMK] model) approaches were used to determine the location of microorganisms within cucumber. The total number of aerobes found within/on cucumbers varied from 10 5 to 10 7 colony‐forming units (CFU) /g. The highest and the least amount of microbiota were respectively found at the blossom end and middle part of the cucumbers and were within the 1st 6 mm of the cucumber surface. A comparison of the calculated thermal death time from the HTMK model with the values obtained from experimental data showed that total aerobic microorganisms were located within 0.65 mm of the fruit surface. DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb09972.x VL - 70 IS - 5 SP - E324-E330 SN - 1750-3841 KW - heat transfer KW - thermal death kinetics KW - modeling KW - blanching ER - TY - JOUR TI - Comparison of differences between lexicons for descriptive analysis of Cheddar cheese flavour in Ireland, New Zealand, and the United States of America AU - Drake, MA AU - Yates, MD AU - Gerard, PD AU - Delahunty, CM AU - Sheehan, EM AU - Turnbull, RP AU - Dodds, TM T2 - INTERNATIONAL DAIRY JOURNAL AB - Flavour lexicons for cheese provide a way to document cheese flavour for both research and marketing. The objective of this study was to compare differences and similarities in three independently developed sensory languages for Cheddar cheese flavour at three different locations (Ireland, New Zealand, United States of America) using an international selection of Cheddar cheeses. Twelve Cheddar cheeses (four from each country) were evaluated by the three panels using the respective sensory languages. Sensory space patterns obtained by principal component analysis were consistent between the three sites indicating that the overall differentiation of the cheeses by each panel was similar. The key flavour characteristics among the cheeses were described by different attributes. Cheeses were grouped by each site by country of origin suggesting international differences in Cheddar cheese flavour. Cross-cultural differences can exist in sensory language and perception, but highly trained panels using standardized, representative languages can provide comparable results. DA - 2005/5// PY - 2005/5// DO - 10.1016/j.idairyj.2004.09.006 VL - 15 IS - 5 SP - 473-483 SN - 0958-6946 KW - sensory analysis KW - cheese flavour KW - international KW - cross-cultural ER - TY - JOUR TI - Chemical and sensory properties of sauerkraut produced with Leuconostoc mesenteroides starter cultures of differing malolactic phenotypes AU - Johanningsmeier, SD AU - Fleming, HP AU - Thompson, RL AU - McFeeters, RF T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: Research was conducted to determine whether Leuconostoc mesenteroides starter cultures with and without malolactic activity (MDC + and MDC ‐ , respectively) influenced sensory and chemical properties of sauerkraut. No sensory differences were found between MDC + and MDC− sauerkraut ( P ≥ 0.05). In addition, sulfur compound profiles of the resulting sauerkraut were nearly identical. Brining at lower NaCl (0.5%) with either inoculum changed both the microbiology and chemistry of the fermenting sauerkraut, leading to decreased sauerkraut sulfur flavor. Quantification of allyl isothiocyanate (AITC), dimethyl disulfide, dimethyl trisulfide (DMTS), methyl methanethiosulfinate, and methyl methanethiosulfonate (MMTSO 2 ) by gas chromatography‐mass spectrometry showed that sauerkraut sulfur flavor correlated linearly with DMTS and MMTSO 2 ( P ≤ 0.01). DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb09989.x VL - 70 IS - 5 SP - S343-S349 SN - 1750-3841 KW - malolactic activity KW - Leuconostoc mesenteroides KW - sauerkraut KW - sulfur compounds ER - TY - BOOK TI - Educating the Net generation AU - Oblinger, J. AU - Oblinger, D. G. CN - LB1027 .E383 2005 DA - 2005/// PY - 2005/// PB - Boulder, CO: EDUCAUSE SN - 0967285321 ER - TY - JOUR TI - Complete genome sequence of the probiotic lactic acid bacterium Lactobacillus acidophilus NCFM AU - Altermann, E AU - Russell, WM AU - Azcarate-Peril, MA AU - Barrangou, R AU - Buck, BL AU - McAuliffe, O AU - Souther, N AU - Dobson, A AU - Duong, T AU - Callanan, M AU - Lick, S AU - Hamrick, A AU - Cano, R AU - Klaenhammer, TR T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Lactobacillus acidophilus NCFM is a probiotic bacterium that has been produced commercially since 1972. The complete genome is 1,993,564 nt and devoid of plasmids. The average GC content is 34.71% with 1,864 predicted ORFs, of which 72.5% were functionally classified. Nine phage-related integrases were predicted, but no complete prophages were found. However, three unique regions designated as potential autonomous units (PAUs) were identified. These units resemble a unique structure and bear characteristics of both plasmids and phages. Analysis of the three PAUs revealed the presence of two R/M systems and a prophage maintenance system killer protein. A spacers interspersed direct repeat locus containing 32 nearly perfect 29-bp repeats was discovered and may provide a unique molecular signature for this organism. In silico analyses predicted 17 transposase genes and a chromosomal locus for lactacin B, a class II bacteriocin. Several mucus- and fibronectin-binding proteins, implicated in adhesion to human intestinal cells, were also identified. Gene clusters for transport of a diverse group of carbohydrates, including fructooligosaccharides and raffinose, were present and often accompanied by transcriptional regulators of the lacI family. For protein degradation and peptide utilization, the organism encoded 20 putative peptidases, homologs for PrtP and PrtM, and two complete oligopeptide transport systems. Nine two-component regulatory systems were predicted, some associated with determinants implicated in bacteriocin production and acid tolerance. Collectively, these features within the genome sequence of L. acidophilus are likely to contribute to the organisms' gastric survival and promote interactions with the intestinal mucosa and microbiota. DA - 2005/3/15/ PY - 2005/3/15/ DO - 10.1073/pnas.0409188102 VL - 102 IS - 11 SP - 3906-3912 SN - 0027-8424 KW - adhesion KW - stress response KW - proteolytic system KW - sugar metabolism KW - in silico analysis ER - TY - JOUR TI - Combination effects of chicken plasma protein and setting phenomenon on gel properties and cross-linking of bigeye snapper muscle proteins AU - Rawdkuen, S AU - Benjakul, S AU - Visessanguan, W AU - Lanier, TC T2 - LWT-FOOD SCIENCE AND TECHNOLOGY AB - Effects of chicken plasma protein (CPP) in combination with setting on surimi gel properties and protein cross-linking were investigated. Addition of CPP (0.5 g/100 g), CaCl2 (10 mmole/kg) and 200 units of thrombin/g CPP in combination with setting at 40 °C for 30 min prior to heating at 90 °C for 20 min resulted in the highest breaking force and deformation (P<0.05). Regardless of CPP addition, myosin heavy chain (MHC) in surimi proteins and natural actomyosin (NAM) underwent polymerization to some extent in the presence of CaCl2 and thrombin. The cross-linking of MHC in surimi proteins were markedly suppressed by the addition of EGTA and NH4Cl, transglutaminase (TGase) inhibitors. No cross-linking of myosin was observed when CPP, CaCl2 and thrombin were added, even with the prolonged incubation time. The result revealed that CPP showed no cross-linking activity and gel strengthening effect of CPP was attributed to its filler effect and proteolytic inhibitory activity. DA - 2005/// PY - 2005/// DO - 10.1016/j.lwt.2004.06.016 VL - 38 IS - 4 SP - 353-362 SN - 1096-1127 KW - myosin heavy chain KW - surimi KW - setting KW - cross-linking KW - chicken plasma ER - TY - JOUR TI - Lactobacilli activate human dendritic cells that skew T cells toward T helper 1 polarization AU - Mohamadzadeh, M AU - Olson, S AU - Kalina, WV AU - Ruthel, G AU - Demmin, GL AU - Warfield, KL AU - Bavari, S AU - Klaenhammer, TR T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Professional antigen-presenting dendritic cells (DCs) are critical in regulating T cell immune responses at both systemic and mucosal sites. Many Lactobacillus species are normal members of the human gut microflora and most are regarded as safe when administered as probiotics. Because DCs can naturally or therapeutically encounter lactobacilli, we investigated the effects of several well defined strains, representing three species of Lactobacillus on human myeloid DCs (MDCs) and found that they modulated the phenotype and functions of human MDCs. Lactobacillus-exposed MDCs up-regulated HLA-DR, CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18, but not IL-10. IL-12 was sustained in MDCs exposed to all three Lactobacillus species in the presence of LPS from Escherichia coli, whereas LPS-induced IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed CD4(+) and CD8(+) T cells to T helper 1 and Tc1 polarization, as evidenced by secretion of IFN-gamma, but not IL-4 or IL-13. These results emphasize a potentially important role for lactobacilli in modulating immunological functions of DCs and suggest that certain strains could be particularly advantageous as vaccine adjuvants, by promoting DCs to regulate T cell responses toward T helper 1 and Tc1 pathways. DA - 2005/2/22/ PY - 2005/2/22/ DO - 10.1073/pnas.0500098102 VL - 102 IS - 8 SP - 2880-2885 SN - 0027-8424 ER - TY - JOUR TI - Dynamic model for mass transfer of solutes in cucumber fermentation AU - Passos, FV AU - Felder, RM AU - Fleming, HP AU - McFeeters, RF AU - Ollis, DF T2 - JOURNAL OF FOOD ENGINEERING AB - A mathematical model for the mass transfer of solutes between whole cucumbers and brine in cucumber fermentation has been developed that takes into account permeation of solutes through stomata in the cucumber skin and through the epidermal cells in the skin, as well as film diffusion through the surrounding brine boundary layer. The model was used to fit experimental data for the time-dependent concentrations of solutes that permeate into the cucumbers (glucose and malate) and out of them (lactic acid, acetic acid, ethanol, and sodium chloride). The rate of lactic acid transport through the stomata was found to be three orders of magnitude greater than that through the epidermis, and the permeabilities of lactic and acetic acids were effectively independent of the brine circulation rate. These results indicate that the rate of permeation of solutes into and out of cucumbers was controlled by mass transfer through the stomata, with neither film diffusion nor epidermal diffusion having a significant effect. The model differential equation for solute transfer combined with a set of rate equations for microbial growth will provide a good basis to establish a complete mechanistic model for the cucumber fermentation process. DA - 2005/6// PY - 2005/6// DO - 10.1016/j.jfoodeng.2004.06.002 VL - 68 IS - 3 SP - 297-302 SN - 0260-8774 KW - diffusion KW - cucumber KW - modeling KW - acids KW - sugar ER - TY - JOUR TI - A hypothesis for the chemical basis for perception of sour taste AU - Johanningsmeier, SD AU - McFeeters, RF AU - Drake, M T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: Sour taste has been considered the simplest of the basic tastes because it is elicited only by hydrogen ions. However, there is not a sufficiently clear understanding of that relationship to allow sour taste intensity to be predicted and rationally modified in foods. On the basis of analysis of sensory data from our laboratory and reanalysis of previously published data, we propose a new hypothesis for the chemical basis for sour taste perception: The intensity of sour taste perception in acid solutions or acidified foods is linearly related to the molar concentration of all organic acid species with at least 1 protonated carboxyl group plus the molar concentration of free hydrogen ions. This hypothesis implies that, on a molar basis, different organic acids will be equally sour, provided at least 1 carboxyl group is protonated. The major effect of pH on sour taste will be to determine the degree of protonation of organic acids. If this hypothesis is confirmed, it will provide a new understanding of the chemical basis for this basic taste perception and have broad usefulness in the formulation of products in which sour taste is an important component of flavor. DA - 2005/3// PY - 2005/3// DO - 10.1111/j.1365-2621.2005.tb07111.x VL - 70 IS - 2 SP - R44-R48 SN - 1750-3841 KW - undissociated KW - organic KW - acids KW - protonated KW - sour taste ER - TY - JOUR TI - Calculation of overall heat transfer coefficients in a triple tube heat exchanger AU - Batmaz, E AU - Sandeep, KP T2 - HEAT AND MASS TRANSFER DA - 2005/1// PY - 2005/1// DO - 10.1007/s00231-004-0546-0 VL - 41 IS - 3 SP - 271-279 SN - 1432-1181 ER - TY - JOUR TI - Measures of human population structure show heterogeneity among genomic regions AU - Weir, BS AU - Cardon, LR AU - Anderson, AD AU - Nielsen, DM AU - Hill, WG T2 - GENOME RESEARCH AB - Estimates of genetic population structure (F(ST)) were constructed from all autosomes in two large SNP data sets. The Perlegen data set contains genotypes on approximately 1 million SNPs segregating in all three samples of Americans of African, Asian, and European descent; and the Phase I HapMap data set contains genotypes on approximately 0.6 million SNPs segregating in all four samples from specific Caucasian, Chinese, Japanese, and Yoruba populations. Substantial heterogeneity of F(ST) values was found between segments within chromosomes, although there was similarity between the two data sets. There was also substantial heterogeneity among population-specific F(ST) values, with the relative sizes of these values often changing along each chromosome. Population-structure estimates are often used as indicators of natural selection, but the analyses presented here show that individual-marker estimates are too variable to be useful. There is inherent variation in these statistics because of variation in genealogy even among neutral loci, and values at pairs of loci are correlated to an extent that reflects the linkage disequilibrium between them. Furthermore, it may be that the best indications of selection will come from population-specific F(ST) values rather than the usually reported population-average values. DA - 2005/11// PY - 2005/11// DO - 10.1101/gr.4398405 VL - 15 IS - 11 SP - 1468-1476 SN - 1549-5469 ER - TY - JOUR TI - Genetic analysis of two bile salt hydrolase activities in Lactobacillus acidophilus NCFM AU - McAuliffe, O AU - Cano, RJ AU - Klaenhammer, TR T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - Two genes, bshA and bshB, encoding bile salt hydrolase enzymes (EC 3.5.1.24) were identified in the genome sequence of Lactobacillus acidophilus NCFM. Targeted inactivation of these genes via chromosomal insertion of an integration vector demonstrated different substrate specificities for these two enzymes. DA - 2005/8// PY - 2005/8// DO - 10.1128/AEM.71.8.4925-4929.2005 VL - 71 IS - 8 SP - 4925-4929 SN - 1098-5336 ER - TY - JOUR TI - Fracture analysis of alginate gels AU - Zhang, JH AU - Daubert, CR AU - Foegeding, EA T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: The fracture properties of alginate gels were investigated using torsion and compression. The gel fracture stress correlated with Ca 2+ and alginate concentration, whereas the fracture strain was insensitive to composition. Considering the relationship of fracture stress with gel network crosslink density and the energy to break covalent and noncovalent bonds, the fracture of alginate gels is hypothesized to result from the disruption of junction zones. Consequently, the fracture stress was the stress required to overcome electrostatic forces that formed junction zones. The fracture stress‐strain relationship for alginate gels can be described by the Blatz, Sharda, adn Tschoegl (BST) equation, suggesting that for a given gel, the fracture strain can be predicted based on fracture stress, small‐strain shear modulus, and a fitted parameter describing nonlinearity of the gel. In addition, the fracture properties were affected by deformation rate. The influence of deformation rate on fracture was ascribed to structural changes among the alginate junction zones. DA - 2005/9// PY - 2005/9// DO - 10.1111/j.1365-2621.2005.tb11471.x VL - 70 IS - 7 SP - E425-E431 SN - 1750-3841 KW - food gels KW - rheology KW - fracture properties KW - large deformation ER - TY - JOUR TI - Finding future food scientists AU - Larick, D. K. T2 - Food Technology DA - 2005/// PY - 2005/// VL - 59 IS - 5 SP - 100 ER - TY - JOUR TI - Characterization of polyacrylamide gels as an elastic model for food gels AU - Zhang, JH AU - Daubert, CR AU - Foegeding, EA T2 - RHEOLOGICA ACTA DA - 2005/7// PY - 2005/7// DO - 10.1007/s00397-005-0444-5 VL - 44 IS - 6 SP - 622-630 SN - 1435-1528 KW - polyacrylamide gels KW - food gels KW - fracture property KW - large deformation ER - TY - JOUR TI - beta-lactoglobulin gelation and modification: Effect of selected acidulants and heating conditions AU - Resch, JJ AU - Daubert, CR AU - Foegeding, EA T2 - JOURNAL OF FOOD SCIENCE AB - ABSTRACT: The effect of acidulant selection, heating temperature, and heating rate on the properties of low-pH β-lactoglobulin (β-Lg) gels and powders derived from these gels was investigated by rheological and microscopic techniques. As isothermal gelation temperature was increased from 75 to 85 °C, gels made with hydrochloric and lactic acid showed more rapid gel formation and increased stress at gel fracture. Thickening and water-holding properties of powders derived from these gels also increased with temperature. Increases in gel strength and derivatized powder functionality appeared to plateau above 85 °C. Gels and derivatized powders prepared with phosphoric acid exhibited attributes similar to samples prepared with HCl and lactic acid at lower temperatures. The ion-specific ability of phosphate to increase denaturation temperature was responsible for the shift in properties of gels made with phosphoric acid. Microscopy revealed temperature effects on network building block size, but variations in rheological properties could not be linked to changes in gel micrographs. Alteration of heating rates from 2.0 to 0.2 °C/min during gelation affected the observed gelation temperature, but had little effect on final gel mechanical properties. Acid selection and gelation temperature offer alternatives to control β-Lg gel strength and the functional properties of instant thickening protein ingredients. DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb09025.x VL - 70 IS - 1 SP - C79-C86 SN - 1750-3841 KW - beta-lactoglobulin KW - gelation KW - derivatization KW - acidulants KW - rheology ER - TY - JOUR TI - The importance of disulfide bridging AU - Swaisgood, HE T2 - BIOTECHNOLOGY ADVANCES DA - 2005/1// PY - 2005/1// DO - 10.1016/j.biotechadv.2004.09.004 VL - 23 IS - 1 SP - 71-73 SN - 0734-9750 ER - TY - JOUR TI - Mathematical modelling of two-phase non-Newtonian flow in a helical pipe AU - Cheng, L AU - Kuznetsov, AV AU - Sandeep, KP T2 - INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS AB - Governing equations for a two-phase 3D helical pipe flow of a non-Newtonian fluid with large particles are derived in an orthogonal helical coordinate system. The Lagrangian approach is utilized to model solid particle trajectories. The interaction between solid particles and the fluid that carries them is accounted for by a source term in the momentum equation for the fluid. The force-coupling method (FCM), developed by M.R. Maxey and his group, is adopted; in this method the momentum source term is no longer a Dirac delta function but is spread on a numerical mesh by using a finite-sized envelop with a spherical Gaussian distribution. The influence of inter-particle and particle–wall collisions is also taken into account. Copyright © 2005 John Wiley & Sons, Ltd. DA - 2005/6/30/ PY - 2005/6/30/ DO - 10.1002/fld.950 VL - 48 IS - 6 SP - 649-670 SN - 1097-0363 KW - non-Newtonian fluid KW - two-phase flow KW - helical pipe KW - orthogonal helical coordinates KW - force-coupling method ER - TY - JOUR TI - Impact of serving temperature on trained panel perception of Cheddar cheese flavor attributes AU - Drake, MA AU - Yates, MD AU - Gerard, PD T2 - JOURNAL OF SENSORY STUDIES AB - ABSTRACT The impact of serving temperature on trained panel perception of Cheddar cheese flavor attributes was determined. Seven cheeses were selected to represent a range of age and flavor profiles. A descriptive sensory panel received 75 h training on 15 terms for cheese flavor attributes and basic tastes from a previously identified sensory lexicon for Cheddar cheese. Three serving temperatures were selected (5, 12, 21C). Cheeses were subsequently evaluated in quadruplicate by the panel at each serving temperature. Cheeses were differentiated on their flavor and taste attributes ( P < 0.0001). Perception of sour taste intensity increased with serving temperature ( P < 0.05). Other flavors and basic tastes did not exhibit a temperature effect or temperature by cheese interaction ( P > 0.05). Panelists noted that cheese was more difficult to evaluate at 21C compared with 12 or 5C. Cheddar cheese serving temperature should not pose an issue for comparing descriptive sensory results from multiple locations. DA - 2005/4// PY - 2005/4// DO - 10.1111/j.1745-459X.2005.00013.x VL - 20 IS - 2 SP - 147-155 SN - 1745-459X ER - TY - JOUR TI - Gel formation of peptides produced by extensive enzymatic hydrolysis of beta-lactoglobulin AU - Doucet, D AU - Foegeding, EA T2 - BIOMACROMOLECULES AB - The purpose of the present study was to identify which peptides were responsible for enzyme-induced gelation of extensively hydrolyzed beta-lactoglobulin with Alcalase in order to gain insight into the mechanism of gelation. Dynamic rheology, aggregation measurements, isoelectrofocusing as well as chromatography and mass spectrometry were used to understand the gel formation. A transparent gel was formed above a critical concentration of peptides while noncovalently linked aggregates appear with increasing time of hydrolysis. Extensive hydrolysis was needed for gelation to occur as indicated by the small size of the peptides. Isoelectrofocusing was successful at separating the complex mixture, and 19 main peptides were identified with molecular weight ranging from 265 to 1485 Da. Only one fragment came from a beta-sheet rich region of the beta-lactoglobulin molecule, and a high proportion of peptides had proline residues in their sequence. DA - 2005/// PY - 2005/// DO - 10.1021/bm0492273 VL - 6 IS - 2 SP - 1140-1148 SN - 1526-4602 ER - TY - JOUR TI - Emulsifying and foaming properties of a derivatized whey protein ingredient AU - Firebaugh, JD AU - Daubert, CR T2 - INTERNATIONAL JOURNAL OF FOOD PROPERTIES AB - A derivatization procedure for the production of a cold gelling whey protein isolate (WPI) has been identified. The cold gelling derivatized whey protein isolate (dWPI) imparted greater viscosity and water holding ability when rehydrated at room temperature than unmodified whey powders. The objective of this study was to further characterize the foaming and emulsifying functionality of the derivatized ingredient. Samples were prepared by hydrating dWPI and WPI in deionized water and, when needed, adjusting the sample pH from 3.4 to 6.8, with 6M NaOH. Yield stress, drainage, and overrun were measured for 6.5% WPI and dWPI foams. Emulsifying capacity and creaming stability were determined for various WPI and dWPI emulsions. The overrun of dWPI foams was approximately 50% lower than WPI foams at pH 3.4 and 6.8. Foams of the derivatized ingredient were significantly more stable than WPI foams. The derivatized ingredient displayed a similar emulsifying capacity to WPI at pH 3.4 and pH 7.0, and differences were not observed in creaming of dWPI and WPI emulsions. Information on foaming and emulsifying ability of derivatized protein ingredients will expedite the development of applications with the novel dairy ingredient, particularly in those foods desiring an all-natural, or all dairy, food label. DA - 2005/// PY - 2005/// DO - 10.1081/jfp-200060245 VL - 8 IS - 2 SP - 243-253 SN - 1532-2386 KW - whey protein KW - emulsifying capacity KW - protein foam KW - functionality ER - TY - JOUR TI - Design of a beverage from whey permeate AU - Beucler, J. AU - Drake, M. AU - Foegeding, E. A. T2 - Journal of Food Science AB - ABSTRACT: Wheypermeate (WP) is a byproduct ofwhey protein ingredient production, and primarily contains water, lactose, and minerals, with minimal fat and protein. The majority of the WP produced in the United States is disposed of via land-spreading or is used as a component in animal feed. However, WP could be utilized in the growing beverage industry. The objectives of this study were to conduct descriptive sensory analysis of a wide selection of commercial beverages and to design a beverage utilizing WP. The descriptive sensory properties (visual, flavor, and texture/mouth-feel) of fifteen commercial beverages were determined using a trained descriptive panel (n= 11).WP with and without hydrolysis of lactose was subsequently incorporated into a basic beverage formula, substituted for 0%, 25%, 50%, 75%, or 100% of water. Consumers (n = 100) evaluated beverages withWP and commercial beverages for overall acceptability, flavor liking, and thirst-quenching ability. Drinks made with lower levels (25% and 50%) of either hydrolyzed or unhydrolyzed WP were more similar to the commercial beverages in visual and flavor properties than beverages containing higher percentages (75% and 100%) ofWP. All drinks made withWP were higher in electrolyte (Na, K, Zn, Mg, P) content compared with a commercial sports beverage (P < 0.05). Beverage incorporation represents a value-added utilization for low levels ofWP DA - 2005/// PY - 2005/// DO - 10.1111/j.1365-2621.2005.tb07203.x VL - 70 IS - 4 SP - S277-285 ER - TY - JOUR TI - An analytical model for fluid flow and heat transfer in a micro-heat pipe of polygonal shape AU - Suman, B AU - Kumar, P T2 - INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER AB - An analytical model for fluid flow and heat transfer in a micro-heat pipe of polygonal shape is presented by utilizing a macroscopic approach. The coupled nonlinear governing equations for fluid flow, heat and mass transfer have been modified and have been solved analytically. The analytical model enables us to study the performance and the limitations of such a device and provides the analytical expressions for critical heat input, dry-out length and available capillary head for the flow of fluid. A dimensionless parameter, which plays an important role in predicting the performance of a micro-heat pipe, is obtained from the analytical model. The results predicted by the model compared with the published results in literature and good agreement has been obtained. The general and analytical nature of the simple model will have its applicability in the design of micro-heat pipes. DA - 2005/10// PY - 2005/10// DO - 10.1016/j.ijheatmasstransfer.2005.05.001 VL - 48 IS - 21-22 SP - 4498-4509 SN - 1879-2189 KW - micro-heat pipe KW - capillary forces KW - critical heat input KW - dry-out length KW - analytical model ER - TY - JOUR TI - Acid adaptation of Vibrio vulnificus and subsequent impact on stress tolerance AU - Bang, W AU - Drake, MA T2 - FOOD MICROBIOLOGY AB - Three strains of Vibrio vulnificus were evaluated for their potential to become acid adapted in tryptic soy broth with 2% NaCl acidified using hydrochloric (pH 5.0), citric or acetic acids (pH 5.5). Control and adapted cells were subsequently evaluated for acid tolerance (pH 3.5) in broths acidified with each acid, respectively. Other cross-protective effects: heat tolerance, cold storage survival, and freeze–thaw resistance were evaluated with cells exposed to broths acidified with hydrochloric acid. Acid adaptation was observed with hydrochloric and citric acids (P<0.05) and was dependent on strain, duration of adaptation time, and acid type. The most pronounced acid adaptation response was with hydrochloric acid, regardless of strain (P<0.05). Treatment with chloramphenicol eliminated the acid tolerance response. The three strains were inactivated within 12 min at 47 °C with or without acid adaptation. Acid adaptation increased freeze–thaw resistance and cold storage survival for one strain following 10 h acid adaptation (P<0.05). DA - 2005/8// PY - 2005/8// DO - 10.1016/j.fm.2004.09.006 VL - 22 IS - 4 SP - 301-309 SN - 1095-9998 KW - Vibrio vulnificus KW - stress KW - acid adaptation ER -