Cold plasma from flexible and conformable paper-based electrodes for fresh produce sanitation: Evaluation of microbial inactivation and quality changes
}, volume={137}, ISSN={["1873-7129"]}, url={https://doi.org/10.1016/j.foodcont.2022.108915}, DOI={10.1016/j.foodcont.2022.108915}, abstractNote={Two types of cold plasma generating paper-based electrodes (CPPE) made with flexible metallized paper were developed to decontaminate fresh produce. As opposed to conventional rigid volume dielectric barrier discharge electrodes currently used for in-package plasma generation for which voltage increases as a function of thickness, two flexible CPPE configurations based on surface dielectric barrier discharge provided high local concentrations of plasma with less voltage which was independent of the thickness of the package. For decontaminating E. coli and Listeria innocua, a circular design for spinach and a kirigami and origami based two-cone design for tomato were used. Generation of ozone and other reactive oxygen and nitrogen species by both CPPE were identified. Activation of the circular CPPE for 10 min reduced E. coli by 4.6 ± 0.6 log CFU per spinach leaf and 4.6 ± 0.5 log CFU per tomato, whereas for Listeria innocua the reductions were 4.8 ± 1.7 log CFU per spinach leaf and 2.0 ± 0.4 log CFU per tomato, respectively. No changes in quality attributes were observed in the post-treated tomatoes, while surface browning was observed on spinach leaves. The results demonstrated the effectiveness of the innovative CPPE for in-package sanitation of fresh produce and its impact on quality. Package conformability, surface properties, and bacterial characteristics played important role in overall inactivation efficacy.}, journal={FOOD CONTROL}, publisher={Elsevier BV}, author={Wang, Qingyang and Pal, Ramendra K. and Yen, Hao-Wei and Naik, Siddhant P. and Orzeszko, Mark K. and Mazzeo, Aaron and Salvi, Deepti}, year={2022}, month={Jul} } @article{wang_lavoine_salvi_2023, title={Cold atmospheric pressure plasma for the sanitation of conveyor belt materials: Decontamination efficacy against adherent bacteria and biofilms of Escherichia coli and effect on surface properties}, volume={84}, ISSN={["1878-5522"]}, DOI={10.1016/j.ifset.2022.103260}, abstractNote={The inactivation efficacy of a cold atmospheric pressure plasma jet against Escherichia coli DH5α adherent cells and biofilms on two conveyor belt materials was evaluated. A 120 s treatment time with a 3 cm treatment distance from the surface reduced both adherent cells (initial 5.6 ± 0.2 log CFU/coupon) and 24 h biofilms (initial 5.8 ± 0.4 log CFU/coupon) on stainless steel (SS) by >4.6 log CFU. While the same treatment reduced adherent cells (initial 5.7 ± 0.5 log CFU/coupon) and 24 h biofilms (initial 6.9 ± 0.5 log CFU/coupon) on polyvinyl chloride (PVC) by 3.8 ± 0.9 and 3.5 ± 0.5 log CFU, respectively. Mature biofilms (72 h grown) were more resistant than 24 h grown biofilms. Lower microbial reductions were observed on scratched surfaces compared to intact ones. No changes were observed in SS and PVC surfaces in terms of chemical properties and visual topography. CAPP is a promising waterless technique for the sanitation of metallic and polymeric conveyor belt surfaces. Cold atmospheric pressure plasma (CAPP) has the potential as waterless technology to inactivate bacteria and their biofilms on food contact surfaces without affecting the material properties and the visual topography. CAPP can be integrated for industrial operation by mounting a CAPP jet on a robotic arm or moving a conveyor belt under a stationary CAPP jet for surface sanitation. This environmental-friendly and residue-free nature technology can be useful in the food industry.}, journal={INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES}, author={Wang, Qingyang and Lavoine, Nathalie and Salvi, Deepti}, year={2023}, month={Mar} } @article{cui_wang_rai_salvi_nitin_2023, title={DNA-based surrogates for the validation of microbial inactivation using cold atmospheric pressure plasma and plasma-activated water processing}, url={https://doi.org/10.1016/j.jfoodeng.2022.111267}, DOI={10.1016/j.jfoodeng.2022.111267}, abstractNote={Cold atmospheric pressure plasma (CAPP) and plasma-activated water (PAW) are emerging nonthermal technologies. Due to the complexity of plasma-generated species as a function of plasma generation conditions, there is a need to develop process validation. This study aims to evaluate plasma interactions with DNA-based surrogates using infrared spectroscopy and gradient boosting decision tree, a machine learning algorithm, for data analysis to validate the decontamination effectiveness of CAPP and PAW. Chitosan-DNA films were developed and treated with CAPP or PAW. Changes in the spectral properties of DNA were characterized with Fourier-transform infrared spectroscopy (FTIR) and correlated to the dosage levels of CAPP and PAW and decontamination efficacy. Using the LightGBM algorithm, both plasma dosage and the inactivation efficacy against bacteria and biofilms were predicted with high accuracy (>89%) based on the spectral features of DNA. In summary, this study illustrates a novel approach for validating the decontamination efficacy of plasma processing.}, journal={Journal of Food Engineering}, author={Cui, Hemiao and Wang, Qingyang and Rai, Rewa and Salvi, Deepti and Nitin, Nitin}, year={2023}, month={Feb} } @article{rivero_wang_salvi_2022, title={Impact of plasma-activated water washing on the microbial inactivation, color, and electrolyte leakage of alfalfa sprouts, broccoli sprouts, and clover sprouts}, volume={81}, ISSN={["1878-5522"]}, url={http://dx.doi.org/10.1016/j.ifset.2022.103123}, DOI={10.1016/j.ifset.2022.103123}, abstractNote={This study investigated plasma-activated water (PAW) as a sanitizer for the washing of sprouts. Alfalfa sprouts, broccoli sprouts, and clover sprouts were washed with PAW, chlorine (Cl, 200 ppm), or deionized water. The inactivation of aerobic mesophilic microorganisms and inoculated Escherichia coli DH5α was evaluated. The quality of sprouts was assessed based on visual color change ( ΔE ) and plant tissue damage (measured by electrolyte leakage). Significant reductions of 1–2 log CFU/g in aerobic mesophilic microorganisms were achieved by PAW and Cl on clover sprouts and alfalfa sprouts. Reductions of E. coli ranging between 1.4 ± 0.4 log CFU/g and 3.5 ± 0.9 log CFU/g were achieved by PAW on the sprouts (original counts: 6.4 to 8.1 CFU/g), which were comparable to Cl except for the case of alfalfa sprouts where Cl achieved the highest inactivation. No significant quality difference in terms of visual color change or electrolyte leakage was observed in sprouts washed by PAW and Cl. • Plasma-activated water (PAW) was evaluated as a novel sanitizer on 3 sprouts. • PAW (5 min) reduced E. coli DH5α from 8.1 to 3.5 log CFU/g in alfalfa sprouts. • PAW and chlorine had comparable reductions of total plate counts and E. coli. • Reductions varied (1.4–7.1 log CFU/g) depending on the types of sprout and washing. • PAW and Cl had similar impacts on the quality of sprouts (color and tissue damage).}, journal={INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES}, publisher={Elsevier BV}, author={Rivero, W. C. and Wang, Qingyang and Salvi, Deepti}, year={2022}, month={Oct} } @article{shah_wang_kathariou_salvi_2023, title={Optimization of Plasma-activated Water and Validation of a Potential Surrogate for Salmonella for Future Egg Washing Processes}, volume={86}, ISSN={["1944-9097"]}, DOI={10.1016/j.jfp.2022.100029}, abstractNote={Plasma-activated water (PAW) is considered a novel sanitizer for the food industry due to the antimicrobial mechanisms exhibited by reactive oxygen and nitrogen species. The plasma operation parameters can affect the chemistry of PAW and can therefore influence its microbial inactivation efficacy. This study statistically optimized the operating conditions of PAW (activation time, distance from nozzle, and volume of water) using response surface methodology. Two optimized conditions of PAW were identified for the inactivation of planktonic cells of the avirulent strain of Salmonella Typhimurium MHM112 providing a minimum reduction of 6.3 log. All three operating parameters significantly affected the physicochemical characteristics (pH, ORP, EC, nitrite, and nitrate) and microbial inactivation efficacy of PAW. Mixing of small batches using the two optimized conditions to obtain larger volumes did not significantly change the microbial inactivation. However, there were significant reductions in nitrite and nitrate concentrations in PAW due to the mixing of batches while the pH and ORP values remained unaffected. The storage of large volumes of PAW for 25 min at 40-46°C, which is the commercial egg washing temperature in the United States, did not significantly impact S. Typhimurium MHM112 inactivation or the physicochemical characteristics of PAW. A validation study using a cocktail of six pathogenic strains of Salmonella revealed no significant differences in inactivation between the avirulent S. Typhimurium MHM112 and the pathogenic strains, suggesting that the avirulent S. Typhimurium MHM112 may serve as a surrogate for sanitation of S. enterica at the optimized conditions of PAW. The results obtained from this study are useful for our long-term goal of evaluating PAW efficacy in surface egg washing to inactivate Salmonella.}, number={1}, journal={JOURNAL OF FOOD PROTECTION}, author={Shah, Urvi and Wang, Qingyang and Kathariou, Sophia and Salvi, Deepti}, year={2023}, month={Jan} } @article{campbell_wang_hall_salvi_2022, title={Physicochemical properties and antimicrobial impacts of plasma‐activated simulated seawater on Escherichia coli}, volume={5}, url={https://doi.org/10.1002/jsf2.46}, DOI={10.1002/jsf2.46}, abstractNote={AbstractBackgroundSome filter‐feeding molluscan shellfish can concentrate harmful bacteria in their intestines during feeding, thus posing a potential food safety risk to human consumers. Plasma‐activated simulated seawater (PASW) generated from non‐thermal plasma may help reduce bacteria in live, molluscan shellfish when used as a disinfectant in depuration systems. This study determined the physicochemical properties of PASW and its antimicrobial efficacy againstEscherichia coliDH5α. These results were then compared to similar data from a plasma‐activated water (PAW) study.ResultsPASW yielded temperatures ranging from 31.0 ± 0.2 to 49.7 1.0°C, pH from 7.21 0.0 to 2.70 0.0, oxidation–reduction potential (ORP) from −15.7 1.0 to 246.0 0.9 mV, and electrical conductivity from 35.4 0.3 to 48.1 1.5 μS/cm after activation by plasma for 1–10 min. Temperature, ORP, electrical conductivity, nitrate (NO3−), and nitrite (NO2−) concentrations of PASW increased while pH decreased with increased plasma activation time. After 2‐ and 5‐min incubations,E.colitreated with PASW5 and PASW10 both resulted in the highest reductions (~3 log CFU/ml). Further, while NO3−and NO2−concentrations in PASW were higher than in PAW of the same plasma exposure time, PAW yielded higherE.colireduction values across treatments.ConclusionResults from this study demonstrate the potential of PASW as a disinfectant for live, molluscan shellfish depuration to provide a microbiologically safer seafood product for human consumers.}, journal={JSFA reports}, publisher={Wiley}, author={Campbell, Vashti M. and Wang, Qingyang and Hall, Steven G. and Salvi, Deepti}, year={2022}, month={May} } @article{wang_salvi_2021, title={Evaluation of plasma-activated water (PAW) as a novel disinfectant: Effectiveness on Escherichia coli and Listeria innocua, physicochemical properties, and storage stability}, volume={149}, ISSN={["1096-1127"]}, url={https://doi.org/10.1016/j.lwt.2021.111847}, DOI={10.1016/j.lwt.2021.111847}, abstractNote={Plasma-activated water (PAW) is an emerging disinfectant with high antimicrobial activity due to a variety of reactive oxygen and nitrogen species. This study evaluated the inactivation efficacy of PAW against planktonic Escherichia coli and Listeria innocua as representatives of gram-negative and gram-positive bacteria, characterized the physicochemical properties of PAW, and investigated the storage stability of PAW. The effectiveness of PAW increased by extending the plasma activation time over water during PAW preparation or the incubation time of bacteria in PAW. PAW also showed higher effectiveness against E. coli than L. innocua: PAW5 (PAW prepared by plasma activation of water for 5 min) reduced E. coli by > 5 log CFU/mL and L. innocua by 1.8 ± 0.5 log CFU/mL within 5 min of bacterial incubation time, while PAW15 (PAW prepared by plasma activation of water for 15 min) reduced E. coli by > 5 log CFU/mL and L. innocua by 3.5 ± 0.6 log CFU/mL within 5 min of bacterial incubation time. Acidic pH and nitrogen species such as NO2− synergistically contributed to the inactivation efficacy of PAW. Fresh PAW showed the highest inactivation efficacy while refrigerated PAW maintained the inactivation efficacy compared to PAW stored at room temperature due to delayed dissipation of reactive species.}, journal={LWT-FOOD SCIENCE AND TECHNOLOGY}, publisher={Elsevier BV}, author={Wang, Qingyang and Salvi, Deepti}, year={2021}, month={Sep} } @article{wang_salvi_2021, title={Recent progress in the application of plasma-activated water (PAW) for food decontamination}, volume={42}, ISSN={["2214-8000"]}, DOI={10.1016/j.cofs.2021.04.012}, abstractNote={Plasma-activated water (PAW) is a novel and promising alternative to traditional food sanitizers. Recently, the inactivation efficacy of PAW has been demonstrated on a wide range of food products against foodborne pathogens, spoilage microorganisms, and harmful chemicals. The effectiveness of PAW relies on various factors related to the plasma generation mechanisms, the target microorganisms, and the food matrix. The inactivation mechanisms of PAW are attributed to the damage of cell integrity and intracellular components by various reactive oxygen and nitrogen species (RONS). Utilization of plasma-activated liquids and hurdle technologies can enhance the inactivation efficacy and diversify the application of this technology. Scaling-up of PAW is still at the very beginning stage and needs further studies before industrial application.}, journal={CURRENT OPINION IN FOOD SCIENCE}, author={Wang, Qingyang and Salvi, Deepti}, year={2021}, month={Dec}, pages={51–60} } @article{karthikeyan_salvi_karwe_2021, title={Modeling of fluid flow, carbohydrate digestion, and glucose absorption in human small intestine}, volume={292}, ISSN={["1873-5770"]}, DOI={10.1016/j.jfoodeng.2020.110339}, abstractNote={The aim of this study was to develop a numerical model for simulating fluid flow, carbohydrate digestion, and glucose absorption in human small intestine. COMSOL Multiphysics® software was used to develop the numerical model. The intestinal geometry parameters, motility parameters, intestinal content properties, and digestion kinetics were obtained from the literature. The glucose absorption process was simulated by assuming that the intestinal tube is enclosed in an outer cylindrical tube with an intermediate diffusion wall. The properties of the intermediate diffusion wall were estimated by comparing numerical predictions with experimental results of in vitro digestion of 5 g glucose and 5 g maltodextrin in water-based food solutions. The jejunum numerical model with the intermediate diffusion wall of 2 mm thickness and the glucose diffusivity value of 5.25 × 10−9 m2/s, predicted the experimental cumulative jejunal glucose absorption values of 3.67 g (glucose feed) and 3.74 g (maltodextrin feed) with an average error of 0.07 g and 0.2 g, respectively.}, journal={JOURNAL OF FOOD ENGINEERING}, author={Karthikeyan, J. S. and Salvi, Deepti and Karwe, Mukund V}, year={2021}, month={Mar} } @article{huang_tian_tan_salvi_karwe_nitin_2020, title={Role of contaminated organic particles in cross-contamination of fresh produce during washing and sanitation}, volume={168}, ISBN={1873-2356}, DOI={10.1016/j.postharvbio.2020.111283}, abstractNote={Outbreaks of foodborne illnesses from fresh produce in recent years have prompted industrial community to consider new practices aimed at reducing the risks of pathogenic microbial contamination on the produce. The presence of organic matter in wash water not only decreases the efficacy of sanitizers to inactivate microorganisms, but also has the potential to transfer microbial contamination to fresh produce. This study aims to comprehensively evaluate the transfer of pathogens from inoculated organic matter to uninoculated fresh produce leaves during washing, as well as determination of the adequate active free chlorine concentration needed to prevent the potential risk of cross-contamination during produce washing process. In addition, the study also characterized the role of particles in increasing the mechanical shear at the leaf surface using numerical simulation. The results showed that cross-contamination of fresh produce occurred significantly in a short time (< 2 min) if the wash water was contaminated. The presence of contaminated organic matter (COD = 0.05 g/L) in wash water enhanced the transfer of bacteria to the fresh produce surface by approximately 1 log unit when compared to planktonic bacterial cells in the wash water. In addition, the presence of organic matter also significantly increased the shear stress at the leaf surface. The adequate active free chlorine (0.005 g/L) in wash water was able to prevent the cross-contamination of fresh produce and inactivate bacteria inoculated on organic contaminants in wash water during washing process. In summary, this study will contribute to guidelines for the design of fresh produce washing process.}, journal={POSTHARVEST BIOLOGY AND TECHNOLOGY}, author={Huang, Kang and Tian, Yuyang and Tan, Juzhong and Salvi, Deepti and Karwe, Mukund and Nitin, Nitin}, year={2020}, month={Oct} } @article{karthikeyan_salvi_corradini_ludescher_karwe_2019, title={Effect of bolus viscosity on carbohydrate digestion and glucose absorption processes: An in vitro study}, volume={31}, ISSN={["1089-7666"]}, DOI={10.1063/1.5126277}, abstractNote={Digestion is the process of breaking down food into smaller nutrient components which can be easily absorbed in the intestinal tract. The aim of this study was to experimentally investigate the influence of bolus (gastric content) viscosity on digestion and nutrient absorption processes, using an in vitro gastrointestinal model, the TIM-1 system. Two types of simple carbohydrates, namely, glucose and maltodextrin, were used as model foods. The initial bolus viscosity was varied (∼1 mPa·s, ∼15 mPa·s, and ∼100 mPa·s) using different glycerol-water proportions. A fluorescent molecular rotor compound (Fast Green For Coloring Food) was used to monitor viscosity changing patterns of the gastrointestinal content during digestion in the in vitro stomach and small intestinal sections. The digested-nutrient absorption data indicated that the initial bolus viscosity did not significantly affect the glucose absorption process in the small intestine. However, an increase in the initial bolus viscosity from ∼1 mPa·s to ∼15 mPa·s reduced the maltodextrin to glucose conversion by 35%. A further increase in the initial bolus viscosity from ∼15 mPa·s to ∼100 mPa·s did not significantly reduce the maltodextrin to glucose conversion.}, number={11}, journal={PHYSICS OF FLUIDS}, author={Karthikeyan, J. S. and Salvi, Deepti and Corradini, Maria G. and Ludescher, Richard D. and Karwe, Mukund V.}, year={2019}, month={Nov} } @article{hemker_nguyen_karwe_salvi_2020, title={Effects of pressure-assisted enzymatic hydrolysis on functional and bioactive properties of tilapia (Oreochroniis niloticus) by-product protein hydrolysates}, volume={122}, ISSN={["1096-1127"]}, DOI={10.1016/j.lwt.2019.109003}, abstractNote={Fish by-product protein can be converted into valuable food and nutraceutical ingredients via proteolysis. The existing process suffers from many limitations such as extended reaction time and nonselective hydrolysis. In this study, protein from tilapia fish by-products was transformed into functional peptides using pressure-assisted enzymatic hydrolysis. Proteins were extracted from the tilapia by-products by isoelectric solubilization and precipitation method. The effects of pressure (38–462 MPa) and hydrolysis time (6–35 min) on the properties of the hydrolysates were investigated using a central composite design. Pressure enhanced protein hydrolysis with a maximum trichloroacetic acid-solubility index (TCA-SI) of 23% obtained at 250 MPa for 35 min. Pressure and time were also vital in improving soluble protein content (5.7 mg/mL), reducing power (44 μg AAE/g), and solubility (71%) of the hydrolyzed products. Improved antioxidant activity, indicated by a significant decrease in IC50 values from 653 μg/mL to 304 μg/mL, was recorded. The combined process facilitated the release of low-molecular-weight peptides and essential amino acids. However, water and oil holding capacities were found to be decreased. Pressure-assisted enzymatic hydrolysis could provide an effective approach for recovering bioactive peptides from fish by-products for industrial applications.}, journal={LWT-FOOD SCIENCE AND TECHNOLOGY}, author={Hemker, Ashutosh Kumar and Nguyen, Loc Thai and Karwe, Mukund and Salvi, Deepti}, year={2020}, month={Mar} } @article{gosavi_salvi_karwe_2019, title={High Pressure-Assisted Infusion of Calcium into Baby Carrots Part II: Influence of Process Variables on beta-carotene Extraction and Color of the Baby Carrots}, volume={12}, ISSN={["1935-5149"]}, DOI={10.1007/s11947-019-2236-4}, number={4}, journal={FOOD AND BIOPROCESS TECHNOLOGY}, author={Gosavi, N. S. and Salvi, D. and Karwe, M. V.}, year={2019}, month={Apr}, pages={613–624} } @article{gosavi_salvi_karwe_2019, title={High Pressure-Assisted Infusion of Calcium into Baby Carrots Part I: Influence of Process Variables on Calcium Infusion and Hardness of the Baby Carrots}, volume={12}, ISSN={["1935-5149"]}, DOI={10.1007/s11947-018-2203-5}, number={2}, journal={FOOD AND BIOPROCESS TECHNOLOGY}, author={Gosavi, Noopur S. and Salvi, Deepti and Karwe, Mukund V.}, year={2019}, month={Feb}, pages={255–266} } @article{karthikeyan_desai_salvi_bruins_karwe_2015, title={Effect of temperature abuse on frozen army rations. Part 1: Developing a heat transfer numerical model based on thermo-physical properties of food}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937676028&partnerID=MN8TOARS}, DOI={10.1016/j.foodres.2015.07.007}, abstractNote={Numerical simulation was carried out to predict the effect of external temperature conditions on thermal behavior of frozen US military rations, during storage and transportation. An army breakfast menu box containing beefsteaks, concentrated orange juice, peppers & onions, French toast, and Danishes, was selected for conducting this study. Thermo-physical properties of each food item were characterized using their composition and differential scanning calorimeter (DSC). Apparent heat capacity method was used to account for the latent heat of phase change during simulation of thawing and freezing. Numerically simulated results were experimentally validated using a gel-based model food system and the food items in the menu box. The average deviation between numerically predicted temperature and experimentally measured temperature for the model food system was approximately 1°C and for the targeted food items the deviation ranged from 2°C to 5°C, depending on the food item.}, journal={Food Research International}, author={Karthikeyan, J.S. and Desai, K.M. and Salvi, D. and Bruins, R. and Karwe, M.V.}, year={2015} } @article{karthikeyan_desai_salvi_bruins_schaffner_karwe_2015, title={Effect of temperature abuse on frozen army rations. Part 2: Predicting microbial spoilage}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937468736&partnerID=MN8TOARS}, DOI={10.1016/j.foodres.2015.07.012}, abstractNote={Numerically simulated heat transfer model of frozen US military rations was combined with microbial kinetics to predict the microbial spoilage of the food products, during two possible temperature abuse scenarios. An army breakfast menu box containing five different food items was selected for conducting this research. One of the food item in the menu box, beefsteak, was chosen for detailed microbial study. A microbial predictive tool was used to identify and evaluate the kinetics of the most prone microorganism that can grow in a beefsteak. Numerical predictions suggested that the food items exposed to external temperatures ranging from 20 °C to 40 °C can be allowed to stay at those temperatures for maximum times of 28.7 h to 11.9 h, respectively. The food items can be allowed to stay inside the broken freezer for a maximum time of 186 h, to ensure microbial safety in the case of freezer failure.}, journal={Food Research International}, author={Karthikeyan, J.S. and Desai, K.M. and Salvi, D. and Bruins, R. and Schaffner, D.W. and Karwe, M.V.}, year={2015} } @article{mahadevan_salvi_karwe_2015, title={High pressure-enhanced infusion in fresh and frozen-thawed cranberries: A comparative study}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84922880226&partnerID=MN8TOARS}, DOI={10.1111/jfpe.12198}, abstractNote={AbstractHigh‐pressure processing (HPP) has been shown to enhance and accelerate infusion of molecules compared with osmosis‐driven diffusion. The primary cause for enhanced HPP infusion is attributed to cell membrane permeabilization. This study tests the validity of this commonly accepted mechanism by conducting HPP (100 MPa–551 MPa) infusion of quercetin into cranberries. Two systems used in this study were fresh cranberries, cells of which are intact, and frozen‐thawed cranberries, cells of which are permeabilized during freeze‐thaw process. Results showed that while fresh and frozen‐thawed cranberries had similar cell membrane permeability after HPP, twice as much quercetin was infused into fresh cranberries as compared with frozen‐thawed cranberries. If cell membrane permeability were the only cause of infusion, the amount of quercetin infused into cranberries in both systems should have been same. These results suggest that enhanced infusion caused by HPP is not just caused by cell permeabilization alone.Practical ApplicationsConventional diffusion based mass transport methods, currently used in the food industry for infusion, are slow processes. In order to accelerate the mass transport, this research investigated the potential of HPP to enhance and accelerate infusion in cranberries. The present study was focused on the comparison of infusion during HPP using fresh cranberries, cells of which were intact and frozen‐thawed cranberries, cells of which were permeabilized (with ruptured cell membranes) by freeze‐thaw process. Results showing increased infusion in fresh cranberries and similar cell permeability in both fresh and frozen‐thawed cranberries suggested that enhanced infusion during HPP was not caused only by cell permeabilization. This research opens new avenues for investigating additional mass transport mechanisms occurring during HPP, which will help develop accurate predictive mass transport models for HPP infusion processes.}, journal={Journal of Food Process Engineering}, author={Mahadevan, S. and Salvi, D. and Karwe, M.V.}, year={2015} } @article{mahadevan_nitin_salvi_karwe_2015, title={High-Pressure Enhanced Infusion: Influence of Process Parameters}, volume={38}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84944169510&partnerID=MN8TOARS}, DOI={10.1111/jfpe.12190}, abstractNote={AbstractHigh‐pressure processing (HPP) has been shown to enhance infusion of small‐size molecules into foods primarily because of cell membrane rupture. The enhanced infusion has been previously explained using increased effective diffusivity, which does not elucidate the actual mass transport mechanisms. This study evaluates and explains the role of transport processes and the influence of process parameters on enhanced infusion of antioxidants by HPP. Frozen‐thawed cranberries were infused with quercetin. A greater amount of quercetin (three times) was infused faster (18 times) in cranberries after HPP (100 MPa–551 MPa at 22C) compared with those infused at ambient conditions. While freeze‐thawing process ruptured cell membranes in cranberries, measured as cell permeability, there was no additional cell rupture after HPP. A similar degree of measured cell permeability before (0.48 ± 0.01) and after HPP (0.48 ± 0.04), and observed enhanced infusion under high‐pressure suggest that cell membrane permeabilization may not be the only cause for high–pressure‐assisted infusion.Practical ApplicationsConventional diffusion‐based mass transport methods currently used in the food industry are slow processes. In order to accelerate the process, this research investigates (1) the potential of high‐pressure processing (HPP) to enhance and accelerate infusion in cranberries and (2) the mechanisms operative during high–pressure‐assisted infusion. The present study was focused on understanding influence of process variables on extent of infusion and cell permeability. HPP significantly enhanced and accelerated infusion of quercetin in cranberries. Additionally, the commonly accepted explanation of cell permeabilization being the only cause for enhanced infusion under high pressure was not found to be operative in the current system of study. The success of this research can highlight the potential of HPP as an alternative technology that will be useful to the food industry to develop a broad class of nutrient infused food products.}, number={6}, journal={Journal of Food Process Engineering}, author={Mahadevan, S. and Nitin, N. and Salvi, D. and Karwe, M.V.}, year={2015}, pages={601–612} } @article{salvi_boldor_aita_sabliov_2011, title={COMSOL Multiphysics model for continuous flow microwave heating of liquids}, volume={104}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79952043055&partnerID=MN8TOARS}, DOI={10.1016/j.jfoodeng.2011.01.005}, abstractNote={A numerical model was developed to simulate temperature profiles in Newtonian as well as non-Newtonian fluids during continuous flow microwave heating by iterative coupling of electromagnetism, fluid flow and heat transport in COMSOL Multiphysics. The model was validated by using extensive experimental data for carboxymethyl cellulose solution and tap water flowing at two different flow rates (1 and 2 l/m) through a 915 MHz continuous flow microwave system at 4 kW of power. The electromagnetic power generation (18–20% error) and average numerical temperature were in fairly good agreement with the average experimental temperatures for carboxymethyl cellulose (R2 = 0.89 at 1 l/m and R2 = 0.91 at 2 l/m) and tap water (R2 = 0.90 at 1 l/m and R2 = 0.81 at 2 l/m).}, number={3}, journal={Journal of Food Engineering}, author={Salvi, D. and Boldor, D. and Aita, G.M. and Sabliov, C.M.}, year={2011}, pages={422–429} } @article{salvi_aita_robert_bazan_2010, title={Dilute ammonia pretreatment of sorghum and its effectiveness on enzyme hydrolysis and ethanol fermentation}, volume={161}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77949652814&partnerID=MN8TOARS}, DOI={10.1007/s12010-010-8932-1}, abstractNote={A new pretreatment technology using dilute ammonium hydroxide was evaluated for ethanol production on sorghum. Sorghum fibers, ammonia, and water at a ratio of 1:0.14:8 were heated to 160 degrees C and held for 1 h under 140-160 psi pressure. Approximately, 44% lignin and 35% hemicellulose were removed during the process. Hydrolysis of untreated and dilute ammonia pretreated fibers was carried out at 10% dry solids at an enzyme concentration of 60 FPU Spezyme CP and 64 CBU Novozyme 188/g glucan. Cellulose digestibility was higher (84%) for ammonia pretreated sorghum as compared to untreated sorghum (38%). Fermentations with Saccharomyces cerevisiae D(5)A resulted in 24 g ethanol /100 g dry biomass for dilute ammonia pretreated sorghum and 9 g ethanol /100 g dry biomass for untreated sorghum.}, number={1-8}, journal={Applied Biochemistry and Biotechnology}, author={Salvi, D.A. and Aita, G.M. and Robert, D. and Bazan, V.}, year={2010}, pages={67–74} } @article{aita_salvi_walker_2011, title={Enzyme hydrolysis and ethanol fermentation of dilute ammonia pretreated energy cane}, volume={102}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79551688625&partnerID=MN8TOARS}, DOI={10.1016/j.biortech.2010.12.095}, abstractNote={This study is the first one ever to report on the use of high fiber sugarcane (a.k.a. energy cane) bagasse as feedstock for the production of cellulosic ethanol. Energy cane bagasse was pretreated with ammonium hydroxide (28% v/v solution), and water at a ratio of 1:0.5:8 at 160 °C for 1 h under 0.9–1.1 MPa. Approximately, 55% lignin, 30% hemicellulose, 9% cellulose, and 6% other (e.g., ash, proteins) were removed during the process. The maximum glucan conversion of dilute ammonia treated energy cane bagasse by cellulases was 87% with an ethanol yield (glucose only) of 23 g ethanol/100 g dry biomass. The enzymatic digestibility was related to the removal of lignin and hemicellulose, perhaps due to increased surface area and porosity resulting in the deformation and swelling of exposed fibers as shown in the SEM pictures.}, number={6}, journal={Bioresource Technology}, author={Aita, G.A. and Salvi, D.A. and Walker, M.S.}, year={2011}, pages={4444–4448} } @article{salvi_boldor_ortego_aita_sabliov_2010, title={Numerical modeling of continuous flow microwave heating: A critical Comparison of COMSOL and ANSYS}, volume={44}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84863654404&partnerID=MN8TOARS}, number={4}, journal={Journal of Microwave Power and Electromagnetic Energy}, author={Salvi, D. and Boldor, D. and Ortego, J. and Aita, G.M. and Sabliov, C.M.}, year={2010}, pages={187–197} } @inproceedings{aita_salvi_2010, title={Technical developments in ethanol production from energy crops}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79951540701&partnerID=MN8TOARS}, booktitle={ACS National Meeting Book of Abstracts}, author={Aita, G.M. and Salvi, D.A.}, year={2010} } @article{salvi_aita_robert_bazan_2010, title={Ethanol production from sorghum by a dilute ammonia pretreatment}, volume={37}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-76949108963&partnerID=MN8TOARS}, DOI={10.1007/s10295-009-0645-5}, abstractNote={Sorghum fibers were pretreated with ammonium hydroxide and the effectiveness of the pretreatment evaluated by enzyme hydrolysis and ethanol production. The treatment was carried out by mixing sorghum fibers, ammonia, and water at a ratio of 1:0.14:8 at 160 degrees C for 1 h under 140-160 psi pressure. Approximately 44% lignin and 35% hemicellulose were removed during the process. Untreated and dilute-ammonia-treated fibers at 10% dry solids were hydrolyzed using combinations of commercially available enzymes, Spezyme CP and Novozyme 188. Enzyme combinations were tested at full strength (60 FPU Spezyme CP and 64 CBU Novozyme 188/g glucan) and at half strength (30 FPU Spezyme CP and 32 CBU Novozyme 188/g glucan). Biomass enzyme hydrolysis was conducted for 24 h. Saccharomyces cerevisiae D(5)A was added post hydrolysis for conversion of glucose to ethanol. Theoretical cellulose yields for treated biomass were 84% and 73%, and hemicellulose yields were 73% and 55% for full strength and half strength, respectively. Average cellulose yield was 38% and hemicellulose yield was 14.5% for untreated biomass. Ethanol yields were 25 g/100 g dry biomass and 21 g/100 g dry biomass for full strength and half strength enzyme concentrations, respectively. Controls averaged 10 g ethanol/100 g dry biomass.}, number={1}, journal={Journal of Industrial Microbiology and Biotechnology}, author={Salvi, D.A. and Aita, G.M. and Robert, D. and Bazan, V.}, year={2010}, pages={27–34} } @article{salvi_ortego_arauz_sabliov_boldor_2009, title={Experimental study of the effect of dielectric and physical properties on temperature distribution in fluids during continuous flow microwave heating}, volume={93}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-62849088751&partnerID=MN8TOARS}, DOI={10.1016/j.jfoodeng.2009.01.009}, abstractNote={Temperature data was collected at multiple locations in tap water, saltwater, and carboxymethylcellulose (CMC) solutions heated in a continuous flow microwave system by use of custom made temperature measurement system employing a single fiber optic probe. Tap water, 3% saltwater and 0.5% CMC solution were pumped through a 915 MHz continuous flow microwave system operating at 4 kW at three flow rates of 1 lit/m, 1.6 lit/m and 2 lit/m. Saltwater absorbed most power (3940 W) out of the 4000 W incident power, followed by CMC solutions (2690 W) and tap water (2626 W). Cross-sectional temperature distribution patterns showed that saltwater had the most uniform temperature distribution followed by tap water; CMC exhibited a non-uniform temperature distribution due to viscosity changes and thermal runaway effects. The study was very useful in enhancing the understanding of continuous flow microwave heating process for a variety of material properties and flow rates.}, number={2}, journal={Journal of Food Engineering}, author={Salvi, D. and Ortego, J. and Arauz, C. and Sabliov, C.M. and Boldor, D.}, year={2009}, pages={149–157} } @article{boldor_balasubramanian_purohit_salvi_gutierrez-wing_rusch_sabliov_2008, title={A continuous microwave system for prevention of invasive species during deballasting operation - Death kinetics}, volume={42}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-60349099310&partnerID=MN8TOARS}, number={3}, journal={Journal of Microwave Power and Electromagnetic Energy}, author={Boldor, D. and Balasubramanian, S. and Purohit, S. and Salvi, D. and Gutierrez-Wing, M.T. and Rusch, K.A. and Sabliov, C.M.}, year={2008}, pages={61–78} } @article{salvi_boldor_sabliov_rusch_2008, title={Numerical and experimental analysis of continuous microwave heating of ballast water as preventive treatment for introduction of invasive species}, volume={9}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-54749152207&partnerID=MN8TOARS}, number={1}, journal={Journal of Marine Environmental Engineering}, author={Salvi, D.A. and Boldor, D. and Sabliov, C.M. and Rusch, K.A.}, year={2008}, pages={45–64} } @inproceedings{ortego_boldor_salvi_rusch_sabliov_2008, title={Temperature profiling of fluids in a continuous flow microwave system using fiber-optic technology}, volume={7}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-63049085942&partnerID=MN8TOARS}, booktitle={American Society of Agricultural and Biological Engineers Annual International Meeting 2008, ASABE 2008}, author={Ortego, J. and Boldor, D. and Salvi, D. and Rusch, K.A. and Sabliov, C.}, year={2008}, pages={4133–4138} } @article{sabliov_salvi_boldor_2007, title={High frequency electromagnetism, heat transfer and fluid flow coupling in ANSYS multiphysics}, volume={41}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-45549094289&partnerID=MN8TOARS}, number={4}, journal={Journal of Microwave Power and Electromagnetic Energy}, author={Sabliov, C.M. and Salvi, D.A. and Boldor, D.}, year={2007}, pages={5–17} } @inproceedings{salvi_sabliov_boldor_2007, title={Numerical modeling and validation of heat transfer in flowing fluid in a focused microwave system}, volume={11 BOOK}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-35648991555&partnerID=MN8TOARS}, booktitle={2007 ASABE Annual International Meeting, Technical Papers}, author={Salvi, D. and Sabliov, C. and Boldor, D.}, year={2007} }