@article{clare_gharst_maleki_sanders_2008, title={Effects of Transglutaminase Catalysis on the Functional and Immunoglobulin Binding Properties of Peanut Flour Dispersions Containing Casein}, volume={56}, ISSN={["1520-5118"]}, DOI={10.1021/jf801641d}, abstractNote={The functionality of light roasted peanut flour (PF) dispersions containing supplemental casein (CN) was altered after polymerization with microbial transglutaminase (TGase). The formation of high molecular weight covalent cross-links was observed with likely development of PF-PF, PF-CN, and CN-CN polymers based on Western blotting patterns visualized using antiserum directed against Ara h 1, Ara h 2, Ara h 3, or casein. The gelling temperature of TGase-treated PF dispersions containing 2.5% CN was significantly raised compared to the nontreated PF-CN control solutions. Furthermore, the gel strength and water holding capacity of cross-linked PF-CN test samples containing 5% CN was increased, while the yield stress and apparent viscosity were lowered compared to control dispersions. The immunological staining patterns were also changed where, in some cases, IgE binding to TGase-treated PF-CN fractions appeared less reactive compared to equivalent polymeric PF dispersions lacking supplemental CN and non-cross-linked PF-CN samples. Perhaps, covalent modification masked IgE peanut protein binding epitopes, at least to some degree, on an individual patient basis. Casein proved to be an effective cosubstrate with PF for creating Tgase modified PF-CN dispersions for use as a novel high protein food ingredient.}, number={22}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Clare, Debra A. and Gharst, Greg and Maleki, Sohelia J. and Sanders, Timothy H.}, year={2008}, month={Nov}, pages={10913–10921} }
 @article{davis_gharst_sanders_2007, title={Some rheological properties of aqueous peanut flour dispersions}, volume={38}, ISSN={["0022-4901"]}, DOI={10.1111/j.1745-4603.2007.00097.x}, abstractNote={The rheological behaviors of aqueous peanut flour dispersions were characterized across a range of conditions, including controlled heating and cooling rates under both large- and small-strain deformations. Fat content of the dry flours influenced rheological changes, as dispersions of higher-fat flours were less viscous than lower-fat flours on an equal weight basis. A roast effect was also apparent, especially for dispersions of the higher-fat flours in which light roast flours were more viscous than dark roast flours. Dispersions of toasted soy flour were more viscous at lower temperatures (<75C), but at higher temperatures, low-fat peanut flour dispersions were more viscous than soy. Centrifugal separation revealed that the insoluble material of all dispersions primarily contributed to the observed rheological responses. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to characterize the soluble and insoluble proteins making up the various dispersions, and these results are discussed in terms of observed rheological phenomena. 
 
 
 
PRACTICAL APPLICATIONS 
 
Peanut flour is a dry powder prepared after partial extraction of peanut oil from roasted peanut seed. This flour, as compared to peanut butter or whole peanut seed, has numerous functional advantages in formulated foods, including improved stability to lipid oxidation, an enriched protein content and the handling ease of a powder. However, there is no published fundamental rheological data pertaining to these ingredients. Accordingly, commercially available peanut flours with varying roast intensities and fat contents were rheologically characterized in aqueous dispersions, both in the absence and presence of heat. Residual fat content in the flours primarily affected rheological behaviors, with high-fat flours being less viscous under equivalent conditions. A yield stress was observed in all dispersions held at 40C, which correlated with stability of the dispersion to particle settling. This data could ultimately aid texture optimization of products containing such flours.}, number={2}, journal={JOURNAL OF TEXTURE STUDIES}, author={Davis, J. P. and Gharst, G. and Sanders, T. H.}, year={2007}, month={Apr}, pages={253–272} }
 @article{gharst_clare_davis_sanders_2007, title={The effect of transglutaminase crosslinking on the rheological characteristics of heated peanut flour dispersions}, volume={72}, ISSN={["0022-1147"]}, DOI={10.1111/j.1750-3841.2007.00442.x}, abstractNote={Peanut flour (PF) is a high-protein ingredient prepared after the partial extraction of oil from roasted peanut seed. Microbial transglutaminase (TGase) catalyzes protein crosslinking via acyl-transfer reactions, resulting in the modification of functional properties such as viscosity, gelation, solubility, and water holding capacity. This work was conducted to observe changes in rheological properties of PF dispersions in the presence and the absence of TGase and amidated pectin (AP). Dispersions were characterized across a range of conditions, including controlled heating and cooling rates under both large- and small-strain deformations. Gelation occurred at temperatures above 78 degrees C using PF dispersions treated with TGase compared to untreated dispersions devoid of the enzyme (about 68 degrees C). The addition of AP (0.5%) resulted in a general increase in viscoelasticity for all dispersions. AP addition also minimized the shift in gel point temperature caused by TGase polymerization reactions. High-molecular-weight polymers were formed in TGase-treated PF dispersions in both the presence and the absence of AP; however, polymer formation was more rapid in PF dispersions without AP. Ortho-phthaldialdehyde assays indicated about 40% protein coupling in PF dispersions treated with TGase compared to about 20% in those containing both AP and TGase. Collectively, these data suggest potential applications of TGase-treated PF dispersions, both in the presence and the absence of AP, for use in peanut-base food products, including protein bars, shakes, and value-added baked goods.}, number={7}, journal={JOURNAL OF FOOD SCIENCE}, author={Gharst, G. and Clare, D. A. and Davis, J. P. and Sanders, T. H.}, year={2007}, month={Sep}, pages={C369–C375} }
 @article{clare_gharst_sanders_2007, title={Transglutaminase polymerization of peanut proteins}, volume={55}, ISSN={["1520-5118"]}, DOI={10.1021/jf062309t}, abstractNote={Transglutaminase promotes protein cross-linking reactions through an acyl transferase mechanism involving protein-bound glutaminyl residues and primary amines including the epsilon-amino group of lysine residues in soy, myosin, gluten, oat globulin, casein, and whey. Herein, we present a first report of exogenous transglutaminase catalysis of several peanut protein fractions, including purified Ara h 1. In most cases, SDS-PAGE banding patterns revealed the formation of high molecular weight polymers while catalysis of Ara h 1 resulted in distinct dimer formation. Cross-linking effects were accomplished in the presence and absence of the reducing reagent, dithiothreitol. Ortho-phthaldialdehyde assays, used to quantify the degree of polymerization, indicated approximately 21% and approximately 30% coupling over a similar time interval, using either cold hexane extracted peanut protein fractions or lightly roasted flour dispersions, respectively. Rheological measurements established that transglutaminase-modified peanut extracts exhibited lowered viscosity readings compared to nontreated dispersions. Peanut protein polymers and glycoprotein conjugates, created by covalent linkage between protein substrates and monosaccharide amino sugars, exhibited similar IgE binding activity, compared to control solutions. These results suggested that potential allergic responses were not enhanced after enzymatic modification. Ultimately, these approaches may provide novel peanut-based food ingredients with unique functional characteristics for expanded applications within the world marketplace.}, number={2}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Clare, D. A. and Gharst, G. and Sanders, T. H.}, year={2007}, month={Jan}, pages={432–438} }
 @article{gharst_hanson_kathariou_2006, title={Effect of direct culture versus selective enrichment on the isolation of thermophilic Campylobacter from feces of mature cattle at harvest}, volume={69}, ISSN={["1944-9097"]}, DOI={10.4315/0362-028X-69.5.1024}, abstractNote={Campylobacterjejuni and Campylobacter coli are leading bacterial causes of human gastroenteritis in the United States and other industrialized nations. These organisms frequently colonize avian hosts, including commercial poultry, but are also found in the gastrointestinal tract of other warm-blooded animals, including swine, sheep, and cattle. This study investigated the effect of direct culture versus selective enrichment on the isolation of thermophilic Campylobacter from the colon of 610 cattle. Fecal samples were taken from the colon of mature cattle (older than 30 months of age) immediately after slaughter in a commercial abattoir over a period of 17 months. Campylobacter was isolated from 23.4% of the animals. Most (93%) of the culture-confirmed Campylobacter isolates were C. jejuni, with the remaining 7% being C. coli. Additionally, of the 143 samples from which pure cultures of Campylobacter could be isolated, 72 (50.3%) were positive only with selective enrichment, 18 (12.6%) were positive only with direct plating, and 53 (37.1%) were positive by both methods. The data suggest that, even though selective enrichment was more effective than direct plating, both direct plating and selective enrichment protocols might need to be employed for optimal surveillance of C. jejuni in fecal material from cattle.}, number={5}, journal={JOURNAL OF FOOD PROTECTION}, author={Gharst, G and Hanson, D and Kathariou, S}, year={2006}, month={May}, pages={1024–1027} }