Progress 10/01/10 to 09/30/15
Outputs
Target Audience:Food Scientists, Food Processors, Regulating Agencies Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?PI of the project provided training of graduate students and one-on-one mentoring. Graduate students and post-doc attended various national and international conferences which provided them the opportunitiesfor professional development. How have the results been disseminated to communities of interest?The results were published in peer reviewed journals as well as presented at various national and international conferences. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 1. B - (Develop new and improved processing technologies) Project Title: High hydrostatic pressure (HPP) assisted infusion of phytochemical antioxidants into fruits and vegetables This study investigated, as a model system, HPP infusion of quercetin into cranberries. The objective of the study was to test whether enhanced infusion of quercetin can be achieved using HPP and to test whether the commonly accepted mechanism of cell permeabilization is operative in this model system. Two systems were used in this study - fresh cranberries, cells of which are intact and frozen-thawed cranberries, cells of which are already permeabilized during freeze-thawing process. Infusion was enhanced under HPP (up to 550 MPa), when compared to infusion at ambient conditions (control), in both fresh and frozen-thawed cranberries. While the amount of quercetin infused under pressure was 3-5 times that in control, it was independent of the applied pressure in the range (100 MPa - 550 MPa)investigated. Low pressure of 5 MPa was sufficient to cause enhanced infusion in frozen-thawed cranberries. Furthermore, pressure cycling treatment (1, 2 and 5 cycles) significantly increased quercetin infused. Unlike other studies, we did not find additional cell permeabilization in frozen-thawed cranberries after HPP, although amount infused was more under HPP. This result suggested that the commonly accepted mechanism may not be the only cause of enhanced infusion. In addition, while both fresh and frozen-thawed cranberries showed no difference in their cell-membrane permeability after HPP, the amount of quercetin infused in fresh cranberries under high pressure was 2 times greater than that infused into frozen-thawed cranberries under similar conditions. If cell-membrane rupture were the only cause of infusion, then the amount infused into both, fresh and frozen-thawed cranberries, should have been equal. Our results show that pressure-enhanced infusion process is much more involved than previously postulated permeabilization-based mechanisms and is perhaps caused by both pressure-enhanced mass transport and cell-permeabilization assisted mass transport. Understanding the actual mechanisms of transport under pressure may enable to develop process guidelines that will help the food industry to develop value-added foods. In another project, weinvestigated the effectiveness of High Pressure Processing (HPP) as an infusion technique for calcium infusion in enzyme treated baby carrots. It was found that the amount of calcium infused with HPP was significantly higher than that infused by vacuum infusion and osmotic infusion.We were able to achieve infusion of calcium up to 150 mg/serving of carrots (equivalent to 15 % RDI) without significantly affecting their texture and color. Project Title: Process non-uniformity during high hydrostatic pressure processing of heterogeneous foods The purpose of this project was to determine if a pressure profile would develop inside a heterogeneous food system, such as a soft food with hard inclusions, during high pressure processing (HPP) that could lead to non-uniformity in microbial inactivation. Model systems consisting of a gel with a wood rod inclusion, embedded glass wool, or plaster of Paris (POP) particles were inoculated with Listeria innocua or Saccharomyces cerevisiae and subjected to HPP. Real-time measurements of the response of bacteria to HPP were also studied to elucidate the mechanisms of microbial inactivation. It was found that in a model systemconsisting of 2% glass wool in gel there was 1 log cfu/g less inactivation of Listeria innocua compared to pure gel. No differences were found in the inactivation of bacteria at different positions in the model system consisting of gel with wood inclusion. The inactivation of yeast was 1 log cfu/g less in gel containing 2% POP particles compared to pure gel. Using rigorous mathematical modeling it was determined that von Mises stresses and pressure gradients formed very close to the inclusions, indicating pressure non-uniformity. In a related study that focused onreal-time inactivation measurements due to HPP, cell membrane damage was detected using propidium iodide during pressurization and holding time, but not during depressurization. Project Title: Effect of Surface Roughness in Model and Fresh Fruit Systems on Microbial Inactivation Efficacy of Cold Atmospheric Pressure Plasma Suitability of Cold Atmospheric Pressure Plasma (CAPP) for fresh produce decontamination, as affected by surface roughness, was studied using a model system. Experiments were carried to relatively quantify active plasma species in CAPP. Experiments using a model system (closed coat sandpapers with roughness- 6 µm to 16 µm) showed a 0.52 log higher inactivation of E. aerogenes on the smoothest sandpaper (2.08 log inactivation) and the difference was statistically significant from the roughest sandpaper. Fruit surfaces results showed 1.25 log higher inactivation on apples (1.86 log inactivation) which were the smoothest and the difference was statistically significant from the roughest fruit which were cantaloupes.Emission spectrum from OES indicated the presence of reactive oxygen and nitrogen species with potential to cause microbial inactivation. Objective 1.C - (Develop mathematical models to enhance understanding of, and optimize food processes) Project Title: Temperature distribution in high pressure vessels during high pressure high temperature process and its impact on safety Numerical simulation results obtained so far show significant non-uniformity in temperature in high pressure vessels (vertical and horizontal) during HPP due to water addition, adiabatic compression heating, conduction heat loss, and natural convection cooling at the vessel wall. The temperature of water added for compression was found to have a major impact on the temperature distribution as well as onthe inactivation of Clostridium botulinum. Coefficient of variance COV, which is an indicator of non-uniformity was found to be higher for a vertical vessel as compared to a horizontal vessel of similar scale and dimensions. The experimental quantification of temperature non-uniformity using ALP (alkaline phosphates) present in milk showed significant difference in inactivation of enzyme at different locations in the vertical vessel. It was found that the non-uniformity in inactivation was dominated in the axial direction compared to the radial direction and a maximum difference of approximately 8-10% was found in the residual enzyme activity, within the vessel. The inactivation shown by the experiments followed the same trend as predicted by the numerical simulation. Project Title: Effect of temperature fluctuations on freeze-thaw characteristics and quality of frozen army rations Our model incorporated phase change behavior, complex 3D geometry, natural convective airflow in the headspace of the box, and coupling the model with microbial kinetics was also successful. Two possible temperature fluctuation scenarios during cold chain transportation that were evaluated were (a) exposed to high ambient temperature while shifting between two cold systems for prolonged time and (b) freezer breakdown. A correlation that relatedmaximum allowed exposure time at different high ambient temperatures (20, 25, 30, 35, 40 °C) was deveoped. The maximum allowable time for the freezer breakdown, before microbial spoilage of the food in the ration occurred,was around 186 hours.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
M. Khurana and M.V. Karwe, 2013. Parameters Affecting the Accuracy of Temperature Measurements during High Hydrostatic Pressure Processing, Journal of Food Process Engineering, 36(1), pp.50-57.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2011
Citation:
L. Zhang and M.V. Karwe, Effect of Food Product Properties and Package Dimensions on Non-uniformity of Microbial Inactivation during High-Pressure High-Temperature Process, IFT Annual Meeting, New Orleans, USA (2011).
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2011
Citation:
Swetha Mahadevan and Mukund.V. Karwe. High Pressure Enhanced Infusion in Frozen-Thawed Cranberries Without Additional Cell-Membrane Permeabilization, IFT Annual Meeting, New Orleans, USA (2011).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2011
Citation:
Swetha Mahadevan and Mukund.V. Karwe. Enhanced infusion under high pressure: New Insights, 11th International Congress on Engineering and Food, Athens, Greece (2011).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Swetha Mahadevan and Mukund V. Karwe. Pressure Enhanced Infusion Beyond Cell Permeabilization Based Mechanisms, IFT AMFE, Las Vegas, NV, June 2012.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Swetha Mahadevan and Mukund V. Karwe. Enhanced Infusion Under Pressure With and Without Induced Cell-Membrane Permeabilization Conference of Food Engineers (CoFE), Leesburg, VA, (April 2012).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
K. Desai, J.S. Karthikeyan, R. Bruins, and M.V. Karwe, "Effect of temperature fluctuations on microbial quality of frozen army rations," IFT AMFE, Las Vegas, NV, June 2012.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Jos� Antonio Maldonado, Abilash Nair, Mukund Karwe, Alberto Cuitino, and Donald Schaffner. Process Non-Uniformity during High Hydrostatic Pressure Processing of Heterogeneous Foods. IFT Annual Meeting, Chicago, IL, July 2013.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Maldonado, J.A.; Schaffner, D.W.; Cuitino, A.M.; Karwe, M.V. 2015. In-situ studies of microbial inactivation during high pressure processing. High Pressure Research. DOI:10.1080/08957959.2015.1111887
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Maldonado, J.A.; Nair, A.; Schaffner, D.W.; Cuitino, A.; Karwe, M.V. Pressure non-Uniformity during High Pressure Processing of Heterogeneous Foods. 12th International Congress on Engineering and Food, June 2015. Quebec City, Montreal, Canada.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
Maldonado, J.A. 2015. Pressure non-Uniformity in Heterogeneous Foods during High Pressure Processing. Ph.D. dissertation, Rutgers, the State University of New Jersey. New Brunswick, New Jersey, USA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Bhide, S., Karwe, M.V., Schaffner, D.W. 2015. Effect of surface roughness in model and fresh fruit systems on microbial inactivation efficacy of Cold Atmospheric Pressure Plasma. IFT Annual Meeting, Chicago.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Bhide, S., Karwe, M.V., Schaffner, D.W. 2015. Effect of surface roughness on microbial inactivation efficacy of Cold Atmospheric Pressure Plasma. NYIFT Poster Presentation Competition, New Brunswick, NJ.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Maldonado, J.A.; Schaffner, D.W.; Cuitino, A.; Karwe, M.V. Real-Time Measurements of Microbial Inactivation during High Pressure Processing of Bacteria Suspensions. IFT Annual Meeting, July 2015. Chicago, IL, USA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Gosavi, N.S., Salvi, D. A., Karwe, M. V. 2015. High Pressure Assisted Infusion of Calcium in PME Pre-treated Baby Carrots. 12th International Congress on Engineering and Food (ICEF12) Poster session, Quebec City, Quebec, Canada. June 14 18, 2015.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2012
Citation:
Khurana, M., 2012. TEMPERATURE DISTRIBUTION IN VERTICAL AND HORIZONTAL HIGH PRESSURE VESSELS AND ITS IMPACT ON FOOD SAFETY. Ph.D. dissertation, Rutgers, the State University of New Jersey. New Brunswick, New Jersey, USA.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2016
Citation:
Nair, A., Maldonado, J.A., Miyazawa, Y., Cuitino, A.M., Schaffner, D.W., Karwe, M.V. 2016. Numerical Simulation of Stress Distribution in Heterogeneous Solids During High Pressure Processing. Submitted to Food Research International
|
Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Audience attending professional meetings (IFT)and USDA-NIFA multi-state project (NC 1023)meetings. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? One Ph.D student and three M.S. students were trained on these projects. How have the results been disseminated to communities of interest? Results were presented at national (IFT) meeting in New Orleans and at an International Workshop in Columbus, Ohio. One peer reviewed article has been accepted for publication with minor revisions. What do you plan to do during the next reporting period to accomplish the goals? Perform CLSM on fruit surfaces to determine their surface roughness Verify whether the microbial inactivation trend achieved on the model system can be extended to fruit surfaces Quantify plasma species concentrations and distributions under the plasma jet by using Optical Emission Spectroscopy.
Impacts
What was accomplished under these goals?
Process non-uniformity during high hydrostatic pressure processing of heterogeneous foods Our experiments were done in three different model systems: 20% gelatin and 2% agar gel, which was formed in a 125 mL plastic bottle with a cylindrical wooden dowel of 1.1 cm diameter at the center. This would allow us to simulate a meat-bone system and maintain the mechanical properties and geometry constant throughout experiments. A similar gel as above but, instead of the wooden dowel, we embedded glass wool in the gel (2.5% and 6% v/v), to increase the interface between gel and hard inclusion (approximately 500 times more with 2.5% volume fraction). 3% agar gel, with plaster of Paris particles dispersed as hard inclusions. This allowed us to test much higher volume fractions, up to 27%. The polymer suspensions were heated to approximately 90 ºC. They were then left to cool down at room temperature. Once it reached 40 ºC it was inoculated with a suspension of Listeria innocua or saccharomyces cerevisiae cells at a rate of 1 mL of suspension per 100 mL of gel. The liquid gel was transferred to the bottles with the wood inclusion or glass wool and left to set for 24 hours before HPP at 300 MPa for 6 minutes for Listeria innocua or 275 MPa for 2 minutes for Saccharimyces cerevisiae. For the samples with plaster of Paris, this was added when the gel was at approximately 60 ºC; the gel was kept under agitation until it had cooled down to 40 ºC, when it was inoculated and transferred to the bottles, which were then placed in an ice bath to quickly gel. After high pressure processing, 1 g of the gel with wooden inclusion was sampled from next to the wood inclusion, next to the bottle surface, and between the inclusion and surface. For the other two samples, 20 g of gel were sampled. The samples were homogenized with peptone water (gelatin gels) or PBS (agar gels) to a 1:10 dilution, and then appropriate dilutions were made also with peptone before plating and enumeration. BHI agar was used for Listeria innocua, and YPD agar was used for Saccharomyces cerevisiae. Additionally, we also carried out numerical simulations of stress distribution in a model system composed of gel and a wood inclusion, using a neo-Hookean model. The bulk modulus of the gel was measured using a tabletop high pressure vessel that allowed us to measure the volume of the gel as it was being pressurized. The model was solved with a series of assumed values for the Poisson’s ratio, since we can’t measure the value at this point. Our experiments in the gel with one wood inclusion did not show significant differences between the inactivations at the three different positions, indicating that the stress profile is uniform. However, we found a difference of almost 1 log cfu/g in the inactivations of both organisms between the pure gel and the gel with glass wool. When we increased the glass wool volume fraction to 6%, we observed an additional 0.5 log cfu/g decrease in the inactivation. A similar trend was observed in the gel with plaster of Paris particles, where the inactivation of Listeria innocua decreased by almost 2.5 log cfu/g at 2% v/v of plaster, and by 3 log cfu/g at 13% and 27% v/v. The trend observed with Saccharomyces cerevisiae was different, the inactivation decreased by 1 log cfu/g from the pure gel to the gel with 2% plaster, but then increased again to the levels of the pure gel at 13% and 27% plaster. We think that it is because at larger inclusion volume fractions a larger amount of cells would be exposed to high shear and lower pressure, which can have different effects on the yeast vs. the bacteria cell. We’re in the process of carrying out numerical simulations of stress distribution in systems with several inclusions. Main accomplishments We have shown non-uniformity in the microbial inactivation in a heterogeneous system during high pressure processing. However, in our experiments, the section where there was an effect on microbial inactivation was limited to very near the inclusions, which is why we only observed inactivation profiles with plaster particles and glass fibers and not with the single wood inclusion. Our data constitutes indirect evidence of non-uniformity of stress distribution in heterogeneous system, which contradicts previous assumptions that pressure is uniform in solids during high pressure processing. Project Title: Effect of surface roughness on microbial inactivation efficacy of Cold Atmospheric Pressure Plasma The purpose of this project is to evaluate the role of surface roughness in microbial inactivation due to Cold Atmospheric Pressure Plasma (CAPP) treatment. Specific Objectives To quantify the influence of surface roughness on microbial inactivation by CAPP, using a model system To verify whether the results from the model system can extended to fruit surfaces possessing similar roughness values To detect and quantify active plasma species and correlate their concentrations to microbial inactivation Cold Atmospheric Pressure Plasma (CAPP) is an ionized gas consisting of charged and neutral particles, and radiation of varying wavelengths. Due to its relatively low temperature, CAPP is considered a potentially useful non-thermal food processing technique able to inactivate microorganisms on food surfaces. However, past research has shown different microbial inactivation on surfaces possessing different roughness values. Our study aims to evaluate and quantify this effect of surface roughness and act as a proof of concept that as the surface roughness increases, microbial inactivation decreases. A minor objective of the project is to quantify the active plasma species/reactive species being generated by the plasma jet and correlate their concentration to the microbial inactivation. Experimental design To quantify microbial inactivation as influenced by surface roughness, we needed a surface whose roughness is uniform, measurable, and similar in topology to fruit surfaces. Closed coat sandpapers fulfill this requirement as they have a relatively constant roughness throughout the sheet. Sandpaper sheets of various roughness values (i.e. various grits) that correspond to the typical roughness (Pa) values of various fruits were selected. The surface roughness was quantified using Confocal Laser Scanning Microscopy (CLSM). A fixed area of sandpaper was inoculated with the nonpathogenic surrogate Enterobacter aerogenes and left to dry for two hours. The sandpaper was subjected to plasma treatment for five minutes. Surface temperature of the sandpaper samples never exceeded 50 °C. Experiments were carried out to confirm that there were no contributions of temperature in the inactivation of E. aerogenes. The log reduction in microbial population was determined. Future research plans include validating the achieved microbial inactivation on the sand paper model system using fruit surfaces and quantifying plasma species concentrations and distributions using Optical Emission Spectroscopy. Progress report From the CLSM data, it was found that the sand paper roughness values (Pa) ranged from, 5 mm to 12 mm. Scanning Electron Microscopy (SEM) was used in conjunction with CLSM to view the stacking of grains on sandpaper surfaces and verify the presence of E. aerogenes between the grains. Experiments showed 1-2 log reductions in E. aerogenes following plasma treatment with the log reduction increasing with sandpaper grit number, i.e., decreasing roughness. Main accomplishments We have shown that surface roughness does play a role in microbial inactivation due to CAPP treatment which would serve as a good reference for researchers/industry in using CAPP treatment for decontamination of foods.
Publications
|
Progress 10/01/12 to 09/30/13
Outputs
Target Audience: Food Scientists, Food Processors, Regulating Agencies Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Yes. The results were presented at the Institute of Food TechnologistsAnnual Meeting inChicago, IL, (July 2013). What do you plan to do during the next reporting period to accomplish the goals? In cold atmospheric pressure plasma processing, we will focus on investigating the effect of surface roughness on the effectiveness of plasma to inactivate the microorganisms. Surfaces with known surface roughness will be prepared, inoculated with microorganisms and exposed to cold plasma. The surface roughness will be measured using either an atomic force microscope or a confocal laser scanning microscope. In the project that focused on process non-uniformity during high hydrostatic pressure processing of heterogeneous foods, we will Develop of a method to measure the Poisson’s ratio or some other mechanical property of the material at high pressure. Carry our microbial experiments with different organisms, to determine if the effect of pressure and shear vary. We will look into organisms of different shape and composition of cell walls (grampositive and gram negative). Develop a method to directly determine if pressure is uniform or a pressure profile is developed.
Impacts
What was accomplished under these goals?
In the project that focused on the application of cold/warm atmospheric pressure plasma to inactivate microorganisms on the surfaces of food products, a new cold/warmplasma system was installed and tested. Preliminary experiments were carried out to ensure that bacterial inactivation was taking place due to the charged particles in the plasma and not due to the temperature of plasma. It was found that temperature alone had negligible contribution in inactivating the microorganisms as long asthe temperature of the plasma made from air was less than 55 degrees C near the surface.We were able to get up to 7 log CFU/ml reduction in enterobacter aerogenes population inoculated in Macconkey agar in a petri plate. We are now investigating the effect of surface topology on the effectiveness of cold plasma. In the project that focused on process non-uniformity during high hydrostatic pressure processing of heterogeneous foods, our experiments showed a profile in the inactivation of Listeria innocua. The highest inactivation levels were observed at the interface of the gel and the wood inclusion. At the external surface the inactivation was lower by 0.8 log cfu/g, and it was even lower between the two surfaces by an additional 0.4 log cfu/g. The numerical simulations showed that pressure and stress profiles would develop as the Poisson’s ratio of the material decreases from 0.5 (the maximum possible value for any material) to 0; as the Poisson’s ratio decreases the shear modulus of the material increases for a fixed value of bulk modulus. Our results imply that it is possible to use cold atmosphereic pressure plasma to inactivate enterobacter aerogenes bacteria. The effect of surface topology on the effectiveness of plasma remains to be investigated. In high pressure processing, our results imply that the extent of pressure non-uniformity is not very large although it does exist to some extent. At this time we can say that the effect of pressure non-uniformity on bacterial inactivation is 0.5 to 1 log CFU/g.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2013
Citation:
Mukund V Karwe, Jose Maldonado, Donald W Schaffner, Alberto Cuitino, Pressure Non-Uniformity in Heterogeneous Foods During High Pressure Processing, IFT Annual Meeting, Chicago, July 13-16, 2013.
|
Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: The main aim of this project was to quantify the effect of surrounding temperature fluctuations on chemical and microbial quality of frozen army rations. Frozen UGR-A army rations are manufactured in the US and shipped to deployed US army units around the world. The transportation usually takes around 3-5 months. Ideally these boxes have to be stored at -18C and must have 9 months remaining shelf life. But temperature fluctuations are inevitable which may affect the quality of food items. It is imperative to have a technological solution for the UGR-A rations that would alert the end user to warn about the possible abuse that the food item might have undergone. The research was performed mainly using computer simulation. The influence of different packing materials, the orientation of food items inside the box, influence of nearby food items within the box, and the amount of headspace available for each food product, was included in this study. Three different menu boxes which contained ten different food items were studied. Commercially available finite element based computational software COMSOL Multiphysics was used to develop the heat transfer model in the numerical simulation. Later the model was experimentally validated with real food system and also using gelatin based model food system. Microbial growth prediction of different possible pathogenic and spoilage microorganism was done using modeling toolbox ComBase to predict their kinetics. To evaluate the chemical degradation kinetics, the extents of protein degradation and lipid oxidation were measured in three different controlled temperatures (-4, -12, -18C) by measuring the degraded substances: Total Volatile Base Nitrogen (TVBN) and ThioBarbituric Acid Reactive substance (TBARS. Thawing and freezing curves were obtained for ten food items. Using their individual component data and properties obtained from DSC, the heat transfer model was developed. Validation with experiments produced reasonable results with more accuracy for model food system than real food. This may be explained due to the homogenous nature of model food system. Under three different temperatures the frozen food were chemically stable and did not undergo any significant change. So microbial spoilage was considered to be the major factor influencing quality. Pseudomonas spp was found to have higher growth rate in meat products and the microbial study was done based on this microorganism. Two possible temperature fluctuation scenarios during cold chain transportation are (a) exposed to high ambient temperature while shifting between two cold systems for prolonged time and (b) freezer breakdown. A correlation that relates maximum allowed exposure time at different high ambient temperatures (20, 25, 30, 35, 40C) was developed and evaluated. The maximum allowable time for the freezer breakdown was around 150 hours or 6 days. PARTICIPANTS: J.S. Karthikeyan, K. Desai, R. Bruins, M.V. Karwe TARGET AUDIENCES: U.S. Army, Frozen Food Storage, Shipping, and Handling business. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A generic numerical modeling technique was developed which can be used for analysis of any frozen food system. The main take-home message is that the maximum allowable time for the freezer breakdown was around 150 hours or 6 days before the food in menu boxes is spoiled. Similar to the microbial quality prediction, analysis of chemical quality of food items can also be done. From the results obtained we propose to design a Time -Temperature Integrator (TTI), which, based on kinetic models of microbial growth and heat transfer simulation under different packing and storage scenarios, would indicate whether the product is suitable for consumption or not based on safety concerns.
Publications
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: The overall objectives of this multi-state project are (i) To develop and verify methods for characterization, measurement and prediction of engineering and biochemical properties of foods as needed in process design and analysis, and product development, (ii) To measure and model process dependent kinetic parameters which affect food quality and safety attributes, and (iii) To identify and characterize transport mechanisms occurring in food processes. During the year 2010-11, our contribution was towards objective (iii). A study was undertaken to investigate whether infusion of large size phytochemical antioxidants into fruit substrates can be enhanced and accelerated under high pressure. This study was focused on the role of cell-membrane permeabiliation in high pressure assisted infusion. Frozen-thawed and fresh cranberries were infused with quercetin. Scarified-frozen-thawed and scarified-fresh cranberries were immersed in an infusate which is a hypertonic solution of antioxidant, and high-pressure processed in sealed bags at pressures between 100 and 551 MPa for 1-60 min at room temperature (22 C). Cranberries were scarified because diffusion through cranberry skin is almost negligible even under high pressure. Infused quercetin in the processed cranberry samples was measured by HPLC-UV/Vis detection. As an indirect measure of the amount infused, the polyphenol content of infused cranberries was also measured by Folin-Ciocalteau's spectrophotometric method. Cell membrane permeabilization changes were quantified using impedance spectroscopy. Fruit microstructure was analyzed using light and scanning electron microscopy. The amount of quercetin infused in cranberries processed under high pressure (100-551 MPa/ 22 C/10 min) was found to be thrice that in cranberries processed at ambient pressure conditions (control). For scarified-fresh cranberries, amount of quercetin infused was five times of that in control. Polyphenol content of scarified-frozen-thawed and scarified fresh cranberries after infusion under high pressure increased by 51 per cent and 23 percent, respectively. In addition, infusion under high pressure was much faster than that at ambient conditions: the amount of quercetin that was infused into control in 6 h was infused in only 10 min under high pressure for scarified-frozen-thawed cranberries. Furthermore, the amount of quercetin infused into cranberries processed under high pressure was found to be independent of the applied pressure in the range investigated. Unlike other studies, however, we did not find additional cell permeabilization or microstructural changes in frozen-thawed cranberries after high pressure processing. The results suggest that enhanced infusion in HHPP may be caused by factors in addition to cell permeabilization and that more studies are required to understand the fundamental mechanisms of infusion under HHPP. Our results suggest that enhanced infusion by HHPP may be caused by additional factors, other than cell-membrane permeabilization, and needs further investigation. PARTICIPANTS: Mukund Karwe, Swetha Mahadevan, Meenakshi Khurana, Jose Maldonado TARGET AUDIENCES: Federal regulating agencies (USDA, USFDA), Food Industry, Academia. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our results suggest that enhanced infusion by HHPP may be caused by additional factors, other than cell-membrane permeabilization, and needs further investigation. This research elucidates important aspects of the science of pressure-enhanced infusion. In addition, this works demonstrates the potential of HHPP to develop nutraceutical-enriched food products. This understanding can be used to develop design guidelines that will be useful to the food industry and can be implemented for a broad class of fruits and infusing molecules to develop value-added nutrient rich foods.
Publications
- S. Mahadevan and M.V. Karwe. (2010). Enhanced infusion of natural antioxidants into fruits using high hydrostatic pressure processing. XVIII Brazilian Congress of Chemical Engineering, Foz do Iguacu, Brazil. ISSN 2178-3659. pp. 68-77.
- S Mahadevan and M.V. Karwe. (2011). Enhanced infusion under high pressure: new insights. 11th International Congress on Engineering and Food, Athens, Greece. Congress Proceedings Vol. III. pp 1681-1682.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Numerical simulation of stress distribution inside non homogeneous foods, such as muscle with bones, when subject to high pressure processing pointed at a decreasing pressure gradient from the surface to the regions near the hard inclusions. Based on mechanical properties obtained from literature, when 400 MPa of hydrostatic pressure were applied, only 350 MPa were delivered to the regions near the bone. Concurrently, the same simulations showed the development of a shear gradient in opposite direction of the pressure gradient. This shear gradient decreased from 200 MPa next to the inclusion to zero at the surface. Microbial experiments using turkey drumsticks and bacterial cells (non-pathogenic Salmonella Typhimurium) showed no difference in the microbial inactivation rates of different locations in the meat when samples were subject to high pressure processing at 400 MPa for 3 minutes. We think this is due to shear stress also having an effect on microbial inactivation rates; the lower pressure inside the sample is compensated by higher shear. In another study, the effect of high pressure processing on a cocktail of pathogenic Salmonella strains obtained from peanut butter and other nut-related outbreaks, inoculated into creamy peanut butter was studied. Inoculated (10^6 CFU/g) peanut butter was high pressure processed at 5 conditions of pressures (400- 600 MPa) and hold times (4-18 minutes). Log reductions varied between 1.6-1.9 logs, irrespective of the pressure-time combination used. Control experiments where the cocktail was inoculated into peptone buffer and high pressure processed at 600 MPa for 18 min showed inactivation to below detection limit of 100 CFU/g, confirming that high pressure processing is effective to destroy pathogenic Salmonella in high moisture environments. Pressure cycling at 3 conditions of pressures varying between 400-600 MPa, cycles varying between 3-10 cycles and hold times of 6 minutes for each cycle showed log reductions between 1.7-1.9 logs, showing pressure cycling to be no more effective than non-cycling. These experiments show Salmonella to be very resistant to destruction when exposed to high pressure processing in the low water activity and high fat environment provided by the peanut butter food matrix. PARTICIPANTS: 1) Mukund V. Karwe (PI) 2) Jose Maldonado (Graduate student) 3) Tanya D'souza (Graduate student), 3) Don Schaffner, 4) Alberto Cuitino, 5) Yuta Miyasawa TARGET AUDIENCES: Food Processors, Regulatory Agencies PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The research findings of both studies will help understand the mechanism of microbial inactivation and the effect of the food matrix on microbial inactivation during high pressure processing as well as help establish procedures and product characteristics that need to be taken into consideration when designing high pressure processes for commercial food products, so the safety of those products can be assured.
Publications
- J. A. Maldonado, Y. Miyazawa, M. V. Karwe, A. Cuitino, D. Schaffner. Preliminary evidence of pressure non uniformity during high pressure processing and its effect on microbial inactivation rate. Non-Thermal Processing Workshop and Conference, Montreal (Canada), October 12, 2010.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Aerobic ascorbic acid browning was identified as an important mechanism for browning of pears in MRE pouches. Oxygen scavenger films were used to reduce the initial oxidation reaction, but they gave inconsistent results. The combination of complete removal of headspace in vacuum sealing, which reduces the output of the packaging line to 50%, and agitated retorting to accelerate heat penetration, stabilized the color to acceptable levels at the end of the required shelf life, based on color measurements correlation with the results from a previous sensory panel. A pretreatment with calcium chloride and pectin methylesterase, which aims to cross link the pectin molecules, has been successful in improving the texture of apples but created a bitter off flavor. In another study it was found that anthocyanins, the color compounds, in freshly squeezed Garcinia Indica fruit, were stable to thermal Pasteurization process. PARTICIPANTS: 1) Mukund V. Karwe 2) Jose Maldonado 3) Anand Atre TARGET AUDIENCES: US Army Fruit and fruit juice suppliers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The research findings from the pears MRE project will increase the acceptability of fruit rations among soldiers and decrease loses due to degraded product. Wet pack fruit is an important part of the soldier's MRE rations as it provides a significant amount of vitamin C and other micronutrients. The stability of anthocyanins in Garcinia Indica fruit juice to thermal processing will increase the market value of this healthy tropical fruit juice.
Publications
- J. Maldonado, G. Chiappe, R. Bruins, and M.V. Karwe. Ascorbic acid browning in meal ready-to-eat pear rations. ACS National Meeting, Washington DC, August 16, 2009.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: One of the goals was to determine whether High Hydrostatic Pressire can inactivate enteric pathogens in littleneck hard clams that are consumed raw. We also wanted to investigate the impact of high pressure on the texture, color, and overall quality of clam meat. Littleneck hard clams were pressuruized to 270 MPa and 540 MPa for 3 min and analyzed on an universal texture meter (TA.TX2i) by compression method. Maximum peak force values were used as an index of firmness. Color coordinates of clams were determined using the CIE-LAB system and the results were expressed as lightness (L*), redness (a*), and yellowness(b*). In another study aimed at quantifying target release rate (TRR) for antimicrobials from controlled release packaging (CRP), sodium benzoate was incorporated into two different blown films, one with nylon layer and another with high density polyethylene (HDPE) using full scale cast-film line at Pliant Company (Chippewa Falls, WI). The release of antimicrobial into methanol was quantified by UV/Visible spectrophotometer at 245 nm. PARTICIPANTS: Mukund V. Karwe (PI), Kit Yam (PI), Shalaka Narwankar (graduate student), Gabriel Mootian (graduate student), Aishwarya Balasubramanian (graduate student) TARGET AUDIENCES: Food Processors, Food Packaging Companies PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Preliminary results on the clams study showed that pressurized clams have a firmer texture compared to unpressurized clams. In addition, clams subjected to 270 MPa had consistent and significantly higher values of peak compressive force than those processed at 540 MPa. Removal of adductor muscles showed the opposite trend. Raw clams gave higher values of peak force compared to pressurized samples at both pressures. Thus it is thought that the change in the molecular structure of the adductor muscles plays an important role in the texture of HPP clams. The knowledge gained from this study will be beneficial in marketing high pressure as a technology that improves the texture and overall appearance of bivalves, in addition to increasing their safety. Results from the target release rate (TRR) for antimicrobials from controlled release packaging (CRP), showed that nylon slowed down the release considerably. The quantification of target release rate of antimicrobials will provide predictive guidance with respect to the range of diffusion coefficients needed for microbial inhibition. This would further aid in the production of CRP films suitable for food packaging applications and allow significant advances in food industry to enhance food safety and quality.
Publications
- Narwankar, S.P., Flimlin, G.E., Schaffner, D.W., Tepper, B.J., and Karwe, M.V. (2008). Process Optimization for Microbial Quality and Sensory Evaluation of High Pressure Processed Hard clams (Mercenaria mercenaria). Food Innovation: Emerging Science Technologies, and Applications I (FIESTA), Brisbane, Australia.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: One of the goals in this project is to develop a new generation of packaging materials, known as controlled release packaging (CRP), which can release active compounds such as antioxidants or antimicrobials in a controlled manner to enhance the safety and quality of food. Another objective was investigate procyanidin content and sensory characteristics (color and flavor) of high hydrostatic pressure processed (HHPP) juice as compared to thermally treated and untreated cranberry juice. We also carried out numerical simulation of thermal transport in pressurizing medium (water) during high hydrostatic pressure processing (HHPP) at room temperature and higher initial temperature so as to predict its effect on temperature distribution.
PARTICIPANTS: Mukund V. Karwe, Kit Yam, Xuntao Zhu, Meenakshi Khurana, Gabriella Chiappe
TARGET AUDIENCES: The results are useful for equipment and packaging material manufacturers and food processors.
Impacts
Natural antioxidant tocopherol (vitamin E) was used as an example of active compounds. Tocopherol degradation and lipid oxidation of linoleic acid were measured as a function of rate of tocopherol addition, time, and temperature. It was found that the optimum release rate of tocopherol was around 75ppm per 24hour at 40C. This result proved the concept of target release rate as an optimum rate which provides the longest induction period (shelf life). Five different polymer films containing tocopherol were produced using full scale cast-film line at Pliant Company (WI). Extraction study showed that all films contained above 2700ppm tocopherols. Over time, tocopherols were released from films at rates controlled by film compositions and extended the induction period of lipid oxidation longer than control (no tocopherol). This result demonstrated that we can achieve target release rate by manipulating the polymer compositions of film. High Pressure processing fresh
cranberry juice showed that cranberry juice color is very stable to high pressure as well as thermal processing. Numerical simulation results showed that temperature distribution in the pressurizing medium becomes non-uniform during the high pressure process and this non-uniformity tends to increase with increasing initial temperatures. Numerical predictions were validated using experimental data. The temperature and its distribution in the vessel are of most relevance when a combination of high pressure and high temperature is needed to inactivate spores which are resistant to high pressure alone.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
It was found that squalene, a health promoting, natural compound found in amaranth, is stable during thermal processing operations such as roasting and puffing, with little or no loss. It was also shown that lipophilic extract of amaranth showed strong antioxidant activity. Thermal processing does not seem to have any detrimental effect on the health promoting properties of amaranth. The adsorption properties of β-lactoglobulin (a key component of dairy proteins) onto the polyethersulfone (PES) thin film were investigated using quartz crystal microbalance with dissipation monitoring (QCM-D) and tapping-mode atomic force microscopy (TM-AFM). The breakup dynamics of bubbles in foods was investigated. The breakup of bubbles in a low Reynold's number flow is determined by the Capillary Number, which is the ratio of the viscous to the interfacial stresses acting on the bubble. The effect of changing flow type distribution and the material rheology on the Capillary
Number distributions and hence the bubble breakup in continuous mixer flows was studied.
Impacts
We have shown that squalene, a health promoting, natural compound found in amaranth, is stable during all the processing operations with little or no loss. We also showed that lipophilic extract of amaranth showed strong antioxidant activity which lends support to amaranth being a healthy food grain with good antioxidants properties. Importantly, processing does not seem to have any detrimental effect on the health promoting properties of amaranth.
Publications
- 1.Brady, K., Rosen, R.T., Ho, C.-T., and Karwe, M.V. Effects of Processing on the nutraceutical profile of quinoa. Food Chemistry, Vol. 100, pp. 1209-16, 2007.
- 2.Liu, S.X. and M. Peng. Assessment of Semi-Empirical Mass Transfer Correlations for Pervaporation Treatment of Wastewater Contaminated with Chlorinated Hydrocarbons, in press, JZUS, 2006.
- 3.Peng, M. and S.X. Liu. The Simulation of the Distillation of Multiple-Component Mixtures via Rayleighs Equation. in press, Computer Applications in Engineering Education, 2006.
- 4.Liu, S. X. CFD Application In Membrane Separation Systems. in Computational Fluid Dynamics in Food Processing, ed. D.-W. Sun, CRC Press, 2006.
- 5.Tu, S., H. Li, L. Cai, X. Yu, M. Peng, and S.X. Liu. Development of A New Meat Analog through Twin-Screw Extrusion of Defatted Soy Flour-Lean Pork Blend. Journal of Food Science and Technology International, 11(6): 463-470, 2005.
- 6.Nitin, N. Gadiraju, R.P., and Karwe, M.V. Conjugate heat transfer associated with a turbulent hot air jet impinging on a cylindrical object. Journal of Food Process Engineering, Vol. 29, No. 4, pp. 386-399, August 2006.
- 7.Sensoy, I., Rosen, R.T., Ho, C.-T., and Karwe, M.V. Effect of processing on buckwheat phenolics and antioxidant activity. Food Chemistry, Vol. 99, Issue 2, pp.388-393, 2006.
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Progress 01/01/05 to 12/31/05
Outputs
Too early to report anything. Project started just 2 months ago.
Impacts
It is expected that the results would provide guidelines for food processors using thermal and non-thermal processes to preserve food.
Publications
- No publications reported this period
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