@article{steed_truong_simunovic_sandeep_kumar_cartwright_swartzel_2008, title={Continuous Flow Microwave-Assisted Processing and Aseptic Packaging of Purple-Fleshed Sweetpotato Purees}, volume={73}, ISSN={["1750-3841"]}, DOI={10.1111/j.1750-3841.2008.00950.x}, abstractNote={ABSTRACT:  Pumpable purees from purple‐flesh sweetpotatoes (PFSP) were subjected to microwave heating using a 60 kW, 915 MHz continuous flow system, followed by aseptic packaging in flexible containers to obtain a shelf‐stable product. Initial test runs were conducted using a 5 kW 915 MHz microwave system to measure dielectric in‐line properties and examine the puree temperature profiles. The results demonstrated uniformity in heating of the puree at sterilization temperatures (>121 °C), and the dielectric constants and loss factors were within the range of published values for orange‐fleshed sweetpotato purees. The pilot‐scale test runs in a 60 kW microwave unit produced shelf‐stable puree packages stable at room temperature. Polyphenolic content of the PFSP purees were evaluated and the results showed that while total phenolics increased (5.9%) and total monomeric anthocyanins slightly decreased (14.5%) with microwave application, antioxidant activity determined by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) assays did not significantly change as a result of microwave processing. Color values showed that microwave‐processed samples differed from fresh puree in saturation and hue angle, but not in overall color change. PFSP purees increased in gel strength when microwave processed, packaged, and stored, but the gel could be easily disrupted into flowable purees. Overall, high‐quality retention can be obtained by microwave processing and aseptic packaging of PFSP purees so that they can be used as functional food ingredients.}, number={9}, journal={JOURNAL OF FOOD SCIENCE}, author={Steed, L. E. and Truong, V. -D. and Simunovic, J. and Sandeep, K. P. and Kumar, P. and Cartwright, G. D. and Swartzel, K. R.}, year={2008}, pages={E455–E462} } @article{coronel_simunovic_sandeep_cartwright_kumar_2008, title={Sterilization solutions for aseptic processing using a continuous flow microwave system}, volume={85}, ISSN={["0260-8774"]}, DOI={10.1016/j.jfoodeng.2007.08.016}, abstractNote={The conventional method of sterilization of an aseptic processing system by recirculating hot water cannot be applied to a continuous flow microwave heating system. Therefore, a model solution with dielectric and flow properties similar to that of the food product is required as a sterilization solution. Dielectric properties of solutions of table salt, sugar, CMC, and mixtures of these solutes were measured and correlations for the dependence of dielectric properties on concentration of solute and temperature were developed. Sterilization solutions were prepared by matching the dielectric and rheological properties of solutions prepared from table salt, sugar, and CMC to those of the food product to be processed. Dielectric properties of milk and sweet potato puree were compared to those of salt–sugar–CMC mixtures and a model solution that closely matched the properties of each product was prepared and experimentally tested in a 5 kW continuous flow microwave system operating at 915 MHz. The temperature profile at the exit of the heating section during heating of the sterilization solution was compared to the temperature profile during heating of the product. It was observed that the temperatures during transition from sterilization solution to the product did not change appreciably. Thus, these model solutions can be used as sterilization solutions for aseptic processing using a continuous flow microwave system.}, number={4}, journal={JOURNAL OF FOOD ENGINEERING}, author={Coronel, P. and Simunovic, J. and Sandeep, K. P. and Cartwright, G. D. and Kumar, P.}, year={2008}, month={Apr}, pages={528–536} } @article{brinley_stam_truong_coronel_kumar_simunovic_sandeep_cartwright_swartzel_jaykus_et al._2007, title={Feasibility of utilizing bioindicators for testing microbial inactivation in sweetpotato purees processed with a continuous-flow microwave system}, volume={72}, ISSN={["0022-1147"]}, DOI={10.1111/j.1750-3841.2007.00371.x}, abstractNote={ABSTRACT:  Continuous‐flow microwave heating has potential in aseptic processing of various food products, including purees from sweetpotatoes and other vegetables. Establishing the feasibility of a new processing technology for achieving commercial sterility requires evaluating microbial inactivation. This study aimed to assess the feasibility of using commercially available plastic pouches of bioindicators containing spores of Geobacillius stearothermophilus ATCC 7953 and Bacillus subtilis ATCC 35021 for evaluating the degree of microbial inactivation achieved in vegetable purees processed in a continuous‐flow microwave heating unit. Sweetpotato puree seeded with the bioindicators was subjected to 3 levels of processing based on the fastest particles: undertarget process (F0 approximately 0.65), target process (F0 approximately 2.8), and overtarget process (F0 approximately 10.10). After initial experiments, we found it was necessary to engineer a setup with 2 removable tubes connected to the continuous‐flow microwave system to facilitate the injection of indicators into the unit without interrupting the puree flow. Using this approach, 60% of the indicators injected into the system could be recovered postprocess. Spore survival after processing, as evaluated by use of growth indicator dyes and standard plating methods, verified inactivation of the spores in sweetpotato puree. The log reduction results for B. subtilis were equivalent to the predesigned degrees of sterilization (F0). This study presents the first report suggesting that bioindicators such as the flexible, food‐grade plastic pouches can be used for microbial validation of commercial sterilization in aseptic processing of foods using a continuous‐flow microwave system.}, number={5}, journal={JOURNAL OF FOOD SCIENCE}, author={Brinley, T. A. and Stam, C. N. and Truong, V. D. and Coronel, P. and Kumar, P. and Simunovic, J. and Sandeep, K. P. and Cartwright, G. D. and Swartzel, K. R. and Jaykus, L. A. and et al.}, year={2007}, pages={E235–E242} } @article{kumar_coronel_truong_simunovic_swartzel_sandeep_cartwright_2008, title={Overcoming issues associated with the scale-up of a continuous flow microwave system for aseptic processing of vegetable purees}, volume={41}, ISSN={["1873-7145"]}, DOI={10.1016/j.foodres.2007.11.004}, abstractNote={Continuous flow microwave heating is a promising alternative to conventional heating for aseptic processing of low-acid vegetable purees. However, non-uniform temperature distribution and control of processing parameters are the major hurdles in the implementation of continuous flow microwave heating. This study was undertaken to overcome issues associated with the scale-up of a continuous flow microwave system from pilot plant scale to industrial scale and to conduct extended run times of 8 h based on the procedure developed. Dielectric properties and cross-sectional temperature profiles were measured during processing of green pea puree and carrot puree from 20 to 130 °C in a 5-kW continuous flow microwave system. During processing of green peas, cross-sectional temperature differences of 8.6 and 5 °C were observed at the outlet for center temperatures of 50 and 130 °C respectively. These temperature differences were 32.9 and 3.6 °C for carrot puree. For process scale-up, green pea puree and carrot puree were processed in a 60-kW microwave system with the objective of successful operation for at least 8 h. Static mixers, installed at the exit of each of the microwave applicators, improved temperature uniformity for both purees. Successful completion of processing the purees for 8 h in the 60-kW microwave system showed the potential for the scale-up of a continuous flow microwave system from pilot plant scale to industrial scale.}, number={5}, journal={FOOD RESEARCH INTERNATIONAL}, author={Kumar, P. and Coronel, P. and Truong, V. D. and Simunovic, J. and Swartzel, K. R. and Sandeep, K. P. and Cartwright, G.}, year={2008}, pages={454–461} } @article{coronel_truong_sandeep_cartwright_2005, title={Aseptic processing of sweetpotato purees using a continuous flow microwave system}, volume={70}, DOI={10.1111/j.1365-2621.2005.tb08315.x}, abstractNote={obtain a shelf-stable product. The dielectric properties of SPP were measured, and the dielectric constant and loss obtain a shelf-stable product. The dielectric properties of SPP were measured, and the dielectric constant and loss obtain a shelf-stable product. The dielectric properties of SPP were measured, and the dielectric constant and loss 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 factor were within the range of the published values for fruits and vegetables. Small-scale tests were conducted in a factor were within the range of the published values for fruits and vegetables. Small-scale tests were conducted in a factor were within the range of the published values for fruits and vegetables. Small-scale tests were conducted in a 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 5-kW microwave unit to determine changes in color and viscosity with different thermal treatments. The results of 5-kW microwave unit to determine changes in color and viscosity with different thermal treatments. The results of 5-kW microwave unit to determine changes in color and viscosity with different thermal treatments. The results of 5-kW microwave unit to determine changes in color and viscosity with different thermal treatments. The results of these tests showed that color values ( these tests showed that color values ( these tests showed that color values ( these tests showed that color values ( these tests showed that color values (L*, *, *, *, a a a a a*) and viscosity did not change significantly compared with the untreated *) and viscosity did not change significantly compared with the untreated *) and viscosity did not change significantly compared with the untreated *) and viscosity did not change significantly compared with the untreated *) 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 control. Pilot-scale tests were then conducted in a 60-kW microwave unit where the product was heated to 135 °C control. Pilot-scale tests were then conducted in a 60-kW microwave unit where the product was heated to 135 °C control. Pilot-scale tests were then conducted in a 60-kW microwave unit where the product was heated to 135 °C 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 and held at that temperature for 30 s. The pilot-scale test produced a shelf-stable product with no detectable and held at that temperature for 30 s. The pilot-scale test produced a shelf-stable product with no detectable and held at that temperature for 30 s. The pilot-scale test produced a shelf-stable product with no detectable 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 microbial count during a 90-d storage period at room temperature. This is the 1st report of aseptically packaged microbial count during a 90-d storage period at room temperature. This is the 1st report of aseptically packaged microbial count during a 90-d storage period at room temperature. This is the 1st report of aseptically packaged 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. vegetable puree processed by a continuous flow microwave heating system. vegetable puree processed by a continuous flow microwave heating system. vegetable puree processed by a continuous flow microwave heating system. vegetable puree processed by a continuous flow microwave heating system.}, number={9}, journal={Journal of Food Science}, author={Coronel, P. and Truong, Simunovic J. Van-Den and Sandeep, KP and Cartwright, G. D.}, year={2005}, pages={E531–536} } @misc{cartwright_2006, title={Method for controlling flow of process materials}, volume={7,144,213}, number={2006 Dec. 5}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cartwright, G. D.}, year={2006} } @misc{cartwright_2005, title={Apparatus and method for controlling flow of process materials}, volume={6,953,315}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cartwright, G. D.}, year={2005} } @article{clare_bang_cartwright_drake_coronel_simunovic_2005, title={Comparison of sensory, microbiological, and biochemical parameters of microwave versus indirect UHT fluid skim milk during storage}, volume={88}, ISSN={["1525-3198"]}, DOI={10.3168/jds.S0022-0302(05)73103-9}, abstractNote={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.}, number={12}, journal={JOURNAL OF DAIRY SCIENCE}, author={Clare, DA and Bang, WS and Cartwright, G and Drake, MA and Coronel, P and Simunovic, J}, year={2005}, month={Dec}, pages={4172–4182} } @article{cartwright_mcmanus_leffler_moser_2005, title={Rapid determination of moisture/solids and fat in dairy products by microwave and nuclear magnetic resonance analysis}, volume={88}, number={1}, journal={Journal of AOAC International}, author={Cartwright, G. and Mcmanus, B. H. and Leffler, T. P. and Moser, C. R.}, year={2005}, pages={107–120} }