Progress 02/09/10 to 02/08/15
Outputs
Target Audience:Consumers, producers and processors of food products; scientists and students in food engineering arena Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training of graduate students through their research projects. How have the results been disseminated to communities of interest?Posters and technical presentations at professional society conferences and peer-reviewed publication of findings in scientific journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The data from our study on food safety could be used to evaluate the impact of washing, storage, and cooling practices at the processing facility, during handling or distribution of fresh fruits and vegetables Irradiation of fresh pecans packaged using Modified Atmosphere packaging methods reduces radiation sensitivity to oxidation and assures pathogen decontamination. The application of nano-encapsulated essential oils can be efficiently delivered into inaccessible sites at a controlled rate where pathogens are protected against conventional intervention methods. The coatings are an effective tool to increase shelf life of fresh-cut fruits. Irradiation treatment of fresh produce for decontamination purposes requires knowledge of dose distribution within the produce. If not done properly, produce may be under- or over- exposed to ionizing radiation with the consequent undesirable degradation of produce quality attributes. There is a lot of misleading information regarding irradiation treatment of fresh produce (produce quality characterization and radiation D10 values) and this method ensures a more standardized procedure to ensure the safety and quality of irradiated fresh produce.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
1. Loquercio, A., Castell-Perez, M. E., Gomes, C. and Moreira, R.G. 2015. Preparation of Chitosan-Alginate Nanoparticles for Trans-cinnamaldehyde Entrapment. Journal of Food Science. Nanoscale Food Science Section, 80(10), N2305-N2315.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
1. Omaca, B.; Moreira, R.; Castillo,A.; and Castell-Perez, E. 2015. Growth of Listeria monocytogenes and Listeria innocua on fresh babyspinach leaves: Effect of storage temperature and natural microflora. Postharvest Biology and Technology. 100:4151.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Kim, J.; Moreira, R.; and Castell-Perez, E. 2015. Improving phytosanitary irradiation treatment of mangoes using Monte Carlo simulation. J. of Food Engineering. 149: 137143
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Moreira, R.G. 2014. Vacuum frying versus conventional frying An overview. Eur. J. Lipid Sci. Technol. 116: 723734.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Martinon*, M., Moreira, R.G., and Castell-Perez. 2014. Development of a multilayered antimicrobial edible coating for shelf-life extension of fresh-cut cantaloupe (Cucumis melo L.) stored at 4�C. ). LWT/Food Science and technology. 56: 341-350.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yurttas, Z. S., Moreira, R.G., and Castell-Perez, E. 2014. Combined vacuum impregnation and electron-beam irradiation treatment to extend the storage life of sliced white button mushrooms (Agaricus bisporus). Journal of Food Science. 79, 1: E39-E46. doi: 10.1111/1750-3841.12308
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Karag�z,I., Moreira, R.G., Castell-Perez, M.E. 2014. Radiation D10 values for Salmonella Typhimurium LT2 and an Escherichia coli cocktail in pecan nuts (Kanza cultivar) exposed to different atmospheres. Food Control 39: 146-153.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Omac,B., Puerta-Gomez, A.F., Moreira, R.G. and Castell-Perez, E. 2014. Quantitative Microbial Risk Assessment for Listeria monocytogenes on Fresh Baby Spinach leaves. . IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LO, July 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Omac,B., Puerta-Gomez, A.F., Moreira, R.G. and Castell-Perez, E. 2014. Modeling Growth of Listeria monocytogenes on Fresh Baby Spinach Leaves under Different Storage Temperatures. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LO, July 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Da Silva, P.F. and Moreira, R.G. 2014.The Impact of Thermal History on Vacuum Fried Potato Chips Geometry and Oil Uptake. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LO, July 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Loquercio, A., Castell-Perez, M.E, R.G. Moreira, and Gomes, C. Characterization of Chitosan-Alginate Nanoparticles with entrapped Trans-Cinnamaldehyde. IFT (Institute of Food Technologists) Annual Meeting, Chicago, 2015.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
1. M. Guzel, R.G. Moreira, B. Omac, and E. Castell-Perez. Quantitative Microbial Risk Assessment for Listeria monocytogenes on Fresh-cut Cantaloupe. IFT (Institute of Food Technologists) Annual Meeting, Chicago, 2015.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
M. Guzel, R.G. Moreira, B. Omac, and E. Castell-Perez. Quantitative Microbial Risk Assessment for Listeria monocytogenes on Fresh-cut Romaine lettuce. IFT (Institute of Food Technologists) Annual Meeting, Chicago, 2015.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
M. Guzel, R.G. Moreira, B. Omac, and E. Castell-Perez Modeling Growth of Listeria innocua on Fresh-cut Cantaloupe under Different Storage Temperatures. IFT (Institute of Food Technologists) Annual Meeting, Chicago, 2015
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
M. Guzel, R.G. Moreira, B. Omac, and E. Castell-Perez Modeling Growth of Listeria innocua on Fresh-cut Romaine Lettuce under Different Storage Temperatures. IFT (Institute of Food Technologists) Annual Meeting, Chicago, 2015
|
Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Food scientists, food engineers,a nd food industries 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?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
-ionizing radiation was used to decontaminate spinash leaves and the data was used to quantitatively assess the effectiveness of intervention steps to reduce the risk of contamination of ready-to-eat baby spinach with Salmonella - fresh cut cantaloupe inculated with microorganisms was irradiated to assess the accumulation (growth and internal mobility) of Salmonella Typhimurium LT2 for optimization of decontamination strategies-
Publications
|
Progress 01/01/13 to 09/30/13
Outputs
Target Audience: academics (scietisits, professor, students) and food industry personel 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? Scientid journals and conferences What do you plan to do during the next reporting period to accomplish the goals? Continue working on the goals and objectives of non-thermal projects
Impacts
What was accomplished under these goals?
This study assessed the application of an anti-browning solution using vacuum impregnation (VI) and then electron-beam irradiation as a means to extend the shelf life of sliced white button mushrooms (Agaricus bisporus). A preliminary study helped to determine the best antibrowning solution and VI process parameters. Mushroom slices were impregnated with 2 g/100 g ascorbic acid + 1 g/100 g calcium lactate; 2 g/100 g citric acid + 1 g/100 g calcium lactate; 1 g/100 g chitosan + 1 g/100 g calcium lactate; and 1 g/100 g calcium lactate at different vacuum pressures and times and atmospheric restoration times. Selection of the antibrowning solution and VI parameters was based on texture and color of the mushroom slices. Next, the slices were irradiated at 1 kGy using a 1.35-MeV e-beam accelerator. Physicochemical, sensory, and microbial quality of mushrooms was monitored for 15 d at 4C. The best impregnation process in this study was 2 g/100 g ascorbic acid and 1 g/100 g calcium lactate at 50 mm Hg for 5 min and an atmospheric restoration time of 5 min. The control (untreated) samples suffered structural losses throughout storage. Only the vacuum impregnated irradiated samples had acceptable color by the end of storage. Sensory panelists consistently preferred the samples produced with VI and irradiation because exposure to ionizing radiation inhibited growth of spoilage microorganisms.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Moreira, R.G. and Kim, T. 2013.De-oiling and pretreatment for high quality potato chips. Journal of Food Process Engineering. 36:267-275
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Sevimli, Z. 2013. Externalizing shelf life of sliced mushrooms (agaris bisporus) by using vacuum impregnation and electron beam irradiation. Master Thesis. Biological and Agricultural Engineering, Texas A&m University, College station, TX.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Chimbombi, E., Moreira, R., Castell-Perez, E., and Puerta-Gomez, A. 2013. Assessing accumulation (growth and internal
mobility) of Salmonella Typhimurium LT2 in fresh-cut cantaloupe(Cucumis melo L.) for optimization of decontamination strategies. Food Control. 32: 574-581
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Puerta-Gomez, A.F, Kim J., Moreira, R.G., Klutke, G.-A., and Castell-Perez, M.E. 2013. Quantitative assessment of the effectiveness of intervention steps to reduce the risk of contamination of ready-to-eat baby spinach with Salmonella. Food Control, 31: 410-418.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Sevimli, Z. Moreira, R.G, and Castell-Perez, E. 2013. Extending Shelf Life of Sliced Mushrooms (Agaricus bisporus) by
Vacuum Impregnation and Electron-beam Irradiation. IFT (Institute of Food Technologists) Annual Meeting, Chicago, IL,
July 2013.
|
Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Two graduate students (PhD), worked on the 'Quantitative assessment of the effectiveness of intervention steps to reduce the risk of contamination of ready-to-eat baby spinach with Salmonella' and 'Optimizing phytosanitary irradiation treatment of mangoes using computer simulation' The results were presented at a conference (IFT)and were published in scientific journals. PARTICIPANTS: Individuals: PI: Drs Moreira, Castell-Perez, Klutke, Braby Graduate Students: 2 PhD TARGET AUDIENCES: Target Audience: producers, consumers, students, educators, scientists, engineers Efforts: workshops, formal classroom instruction, demosntrations PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Salmonella and E. coli are clearly a public health concern, since these microorganisms have been associated with food-borne outbreaks from consumption of leafy vegetables. Predictive microbiology is a useful tool to determine the growth of pathogens in foods during processing and storage. The developed dynamic model can be incorporated into risk assessment models to evaluate pathogen growth in baby spinach processing, transport, and distribution modules. Main results are: -Growth models for Salmonella and E. coli in leafy products under fluctuating temperatures for use in a quantitative risk assessment model were developed. -Risk assessment was performed to determine the impact (if any) of different mitigation strategies (washing and irradiation) on the number of pathogens present in ready-to-eat baby spinach using the quantitative model. -The model highlights the need for intervention strategies (sanitation with chemicals, irradiation, or use of antimicrobials) at different stages of the handling and processing line. -The risk-analytic framework will provide both an operational tool for ensuring safety, cost, and quality targets, as well as a strategic tool for guiding new investments and developing risk-based standards for global food safety. Phytosanitary irradiation is recognized as a promising treatment for an alternative to fumigation. However, most of the irradiation is done in pallet loads, resulting in dose variation in fruits. Therefore, accurate dose calculation is needed to ensure proper process control to minimize quality changes. Our objective was to establish the best phytosanitary irradiation treatment for mangoes in pallet loads. Mango's 3-D geometry, ellipsoid shape, based on Computed Tomography data, was used to simulate dose distributions in mangoes using radiation transport code (MCNP5). To calculate average doses at different depths, mango flesh was divided into 20 shells from the surface to the seed. Mango was divided into 0.05-cm vertical sections to calculate doses along the major axis. Radiation energy was 1.25 MeV from a Cobalt-60 source. For one-directional irradiation, doses from the surface to the mango seed had a build-up region at the outermost region (up to 0.13 cm) with only 76% of the average dose. An average dose at the outermost shell up to the center of the fruit (0.90-kGy) was significantly less (1.45-kGy at the middle shell and 1.40-kGy at the inmost shell). When adding 0.1-cm of plastic wrap and 2 % CaCl2 coating to improve dose distribution, the dose at the outermost shell were 1.28 and 1.26-kGy, respectively. These results are crucial since most insects lay eggs just under the produce's skin. For multiple product arrangement, as the number of mangoes increased, the average doses decreased; 1.29-kGy for one mango, 0.87-kGy for two, 0.57-kGy for three, and 0.37-kGy for the fourth mango. Proper control of phytosanitary irradiation treatment is critical to ensure insect elimination while maintaining product quality.
Publications
- Kim, J., Moreira, R.G., Castell-Perez, M.E. and Braby, L. 2012. Optimizing phytosanitary irradiation treatment of mangoes using computer simulation. IFT (Institute of Food Technologists) Annual Meeting, Las Vegas, NA, June 2012.
- Puerta-Gomez, A.F., R.G. Moreira and Castell-Perez, M.E. 2012. Physical Characterization of Octenyl Succinate-Modified Biopolymers for Encapsulation Purposes. IFT (Institute of Food Technologists) Annual Meeting, Las Vegas, NA, June 2012.
- Kim, J., Puerta-Gomez, A.F., R.G. Moreira, Castell-Perez, M.E. and Klutke, G.-A. 2012. Development of a quantitative risk assessment model for Salmonella Typhimurium in fresh baby spinach. IFT (Institute of Food Technologists) Annual Meeting, Las Vegas, NA, June 2012.
- Chimbombi, E., Moreira, R.G., Castell-Perez, M.E. and Puerta-Gomez, A.F.. 2012. Prediction of accumulation (growth and mobility) of Salmonella enterica serovar Typhimurium in fresh cut cantaloupe (Cucumis melo L.) IFT (Institute of Food Technologists) Annual Meeting, Las Vegas, NA, June 2012.
- Puerta-Gomez, A.F., R.G. Moreira and Castell-Perez, M.E. 2012. Comparison of growth rates of Escherichia Coli spp. and Salmonella Typhimurium LT2 in baby spinach leaves (Spinacea oleracea) under slow cooling. IFT (Institute of Food Technologists) Annual Meeting, Las Vegas, NA, June 2012.
- Puerta-Gomez, A.F, Kim J., Moreira, R.G., Klutke, G.-A., and Castell-Perez, M.E. 2013. Quantitative assessment of the effectiveness of intervention steps to reduce the risk of contamination of ready-to-eat baby spinach with Salmonella. Food Control, 31: 410-418.
- Puerta-Gomez, A.F, Moreira, R.G., Kim** J., and Castell-Perez, M.E. 2013. Modeling the growth rates of Escherichia Coli spp. and Salmonella Typhimurium LT2 in baby spinach leaves under slow cooling. Food Control, 29: 11-17.
- Moreira, R.; Puerta-Gomez, A.; Kim, J.; Castell-Perez, M.E. 2012. Factors affecting radiation D-values (D10) of an Escherichia coli cocktail and Salmonella typhimurium LT2 inoculated in fresh produce. J. Food Science, In-Press, revised Proof.
- Brasil, I.M., Gomes,C., Puerta-Gomez, A., Castell-Perez, M.E., Moreira, R.G. 2012. Polysaccharide-based multilayered antimicrobial edible coating enhances quality of fresh-cut papaya. LWT/Food Science and technology. DOI:10.1016/j.lwt.2012.01.005
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: To develop a method to accurately irradiate fresh fruits and vegetables with minimum degradation of their quality attributes We developed a method to estimate the exact dose absorbed by complex-shaped fresh-produce when exposed to ionizing radiation using electron beams. The method uses CT-scan, Monte Carlo methods, and sample positioning to estimate dose uniformity ratio. -The method allows for visualization of dose distribution within the produce (tomato, cantaloupe, lettuce, and spinach)by reconstructing a 3-D image of the target based on the CT-images. -These data are critical to determine radiation D-10 values for various pathogens as a function of dose by using a DUR (dose uniformity ratio) as closer to 1 as possible. -Kinetics of quality degradation in terms of dose can be characterized. -The negligible effect of produce density and composition on radiation D-10 values for Salmonella and E. coli strains was demonstrated. PARTICIPANTS: Dr. Moreira and Dr. Castell-Perez worked in this project advising graduate students and post-doctors TARGET AUDIENCES: The main audience for this study were students, researchers, professionals, producers, etc. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Irradiation treatment of fresh produce for decontamination purposes requires knowledge of dose distribution within the produce. If not done properly, produce may be under- or over- exposed to ionizing radiation with the consequent undesirable degradation of produce quality attributes. There is a lot of misleading information regarding irradiation treatment of fresh produce (produce quality characterization and radiation D10 values) and this method ensures a more standardized procedure to ensure the safety and quality of irradiated fresh produce.
Publications
- Martinon, E.; R.G. Moreira, E. Castell-Perez, and C. Gomes. 2011. Shelf-Life Extension of Fresh-Cut Cantaloupe (Cucumis melo. L.). IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
- Chimbombi, E., Moreira, R.; Kim, J.; and Castell-Perez, E. 2011. Prediction of Targeted Salmonella enterica serovar Typhimurium inactivation in fresh cut cantaloupe (Cucumis melo L.) using electron beam irradiation. J. Food Engineering. 103:409-416
- Kim, J.; Moreira, R. and Castell-Perez, E. 2011. Optimizing irradiation treatment of shell eggs using simulation. J. of Food Science. 76: E173-E177.
- Gomes, C.; Moreira, R.; and Castell-Perez, E. 2011. Radiosensitization of Salmonella spp. and Listeria spp. in ready-to-eat baby spinach leaves. J. Food Science. 76: E141-E148.
- Gomes, C.; Moreira, R.; and Castell-Perez, E. 2011. Poly (DL-lactide-co-glycolide) (PLGA) nanoparticles with entrapped trans-cinnamaldehyde and eugenol for antimicrobial delivery applications. J. Food Science. 76:N16-N24.
- Gomes, C.; Moreira, R.; and Castell-Perez, E. 2011. Microencapsulated antimicrobial compounds as a means to enhance electron beam irradiation treatment of fresh produce. Journal of Food Microbiology. 76(6): E479-E488.
- Kim, J; A.F. Puerta-Gomez, R.G. Moreira, E. Castell-Perez, and G. A. Klutke. Dynamic growth model of Salmonella Typhimurium in baby spinach. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
- Karagoz,I; R.G. Moreira, E. Castell-Perez. Reduction of Detrimental Effect of Irradiation on the Quality of Vacuum Packed Pecans. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
- Kim, J.; A.F. Puerta-Gomez, R.G. Moreira, E. Castell-Perez, and G. A. Klutke. Development of a quantitative risk assessment model for Salmonella Typhimurium in fresh baby spinach. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
- Gomes, C., Moreira, R.G., Castell-Perez, E. 2011. Microencapsulated antimicrobial compounds as a means to enhance electron beam irradiation treatment of fresh produce. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011
- Brasil, I. , Gomes, C., Puerta-Gomez, A., Castell-Perez, M.E., Moreira, R.G. 2011. Freshness retention of minimally processed fruits using multilayered edible coating containing microencapsulated essential oil. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
- Moreira, R.G. 2011. Understanding food irradiation: the case of fresh produce. Discussion Panel on Food losses: A food safety perspective. IFT (Institute of Food Technologists) Annual Meeting, New Orleans, LA, June 2011.
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: A de-oiling process using a centrifuge was developed to ensure maximum reduction of oil content in atmospheric fried potato chips. A commercial simulator was used to optimize a vacuum frying system. Based on the simulation results, a 1.5 cm thick insulation material was installed in the fryer to reduce the energy losses. A de-oiling mechanism was developed and installed, which consists of a centrifuge with a motor attached to the basket shaft, rotating up to 750 rpm (63 g units). A condenser, consisting of a (counter-flow) spiral-coil heat exchanger (SHE) connected to a refrigeration system that uses R404a refrigerant was successfully designed and connected to the system. Vacuum frying (1.33 kPa), with the aid of a de-oiling mechanism, was used to produce low-fat potato chips. The final oil content of the potato chips was 0.072, 0.062, and 0.059 g/g solid for frying temperatures of 120, 130, and 140C, respectively. These values are lower (80-87% less) than those found in the not de-oiled potato chips, which indicates that the de-oiling mechanism is crucial in vacuum frying processing. PARTICIPANTS: 3 master students One PI and one co-PI TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
(1) Published 1 book chapter article, 2 abstracts, and 2 peer-reviewed articles (2) Three Master students successfully graduated during this period.
Publications
- Yagua, C. and Moreira, R. 2010. Characterization of product quality attributes and thermal properties of potato chips during vacuum frying. J. Food Engineering. On-line.
- Moreira. 2010. Vacuum frying. Encyclopedia of Agricultural, Food and Biological Engineering. Editor: Dennis R. Heldman. Taylor and Francis
- Pandey, A.and Moreira, R. 2010. Batch vacuum frying system analysis for potato chips. J Food Process Engineering. On-line
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: The goal of this study was to synthesize spherical poly (DL-lactide-co-glycolide) (PLGA) nanoparticles with entrapped eugenol and trans-cinnamaldehyde for future antimicrobial delivery applications. The emulsion evaporation method was used to form the nanoparticles in the presence of poly (vinyl alcohol) (PVA) as a surfactant. The inclusion of antimicrobial compounds into the PLGA nanoparticles was accomplished in the organic phase. Synthesis was followed by ultrafiltration (performed to eliminate the excess of PVA and antimicrobial compound) and freeze-drying. The nanoparticles were characterized by their shape, size, entrapment efficiency and, antimicrobial efficiency. The entrapment efficiency for eugenol and trans-cinnamaldehyde was approximately 98% and 92%, respectively. Controlled release experiments with the nanoparticles showed a profile with an initial burst followed by a slower release of the antimicrobial entrapped inside the PLGA matrix. Monte-Carlo simulation of irradiation treatment of fresh cantaloupes, lettuce and broccoli heads was used to obtain accurate dose distribution values within the target product. These values in conjunction with experimental D10-values were used to estimate optimum process parameters such as dose and delivery method (single vs. double beam) to effectively decontaminate pathogens (at least 5-logs reduction). A parallel study was conducted on prediction of the inactivation of internalized Salmonella enteric serovar Typhimurium in fresh cut cantaloupe samples. PARTICIPANTS: Dr. Elena Castell-Perez, professor, co-PI - responsible for quality measurements Dr. J. Kim, post-doctor - responsible for Monte Carlo simulation and dosimetry Graduate students who worked in the project TARGET AUDIENCES: Academia Food Industry and produce growers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
All loaded nanoparticles formulations proved to be efficient in inhibiting growth of Salmonella spp. (Gram-negative) and Listeria spp. (Gram-positive) with concentrations ranging from 20 to 10 mg/ml. The results from these predictive models provide a useful tool to target populations of pathogens to deliver optimal dose required for inactivation while minimizing product quality detriment.
Publications
- Gomes, C., Da Silva, P., Jongsoon, K., Castell-Perez, M.E., Moreira, R.G., Sanchez-Plata, M.X., Braby. 2009. Does effectiveness of irradiation treatment depend on fresh produce variety IFT (Institute of Food Technologists) Annual Meeting, Anaheim, CA.
- Gomes C, Da Silva P, Moreira RG, Castell-Perez ME, Ellis, EA, Pendleton M. 2009. Understanding E. coli internalization in lettuce leaves for optimization of irradiation treatment. Int. J. of Food Microb. 135(3):238-247.
- Kim J,Moreira RG, Castell-Perez ME. 2008. Validation of irradiation of broccoli with a 10 MeV electron beam accelerator. J. of Food Eng 86(4): 595-603.
- Kim J,Moreira RG, Castell-Perez ME. 2009. Simulation of irradiation treatment of romaine lettuce (Lactuca sativa L. var. longifolia). IFT (Institute of Food Technologists) Annual Meeting, Anaheim, CA.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Application of "tailored" MAP for irradiation treatment of bagged leafy vegetables helps maximize the lethality of the irradiation process and minimize the dosage levels while decreasing quality detrimental effects. PARTICIPANTS: This project provided opportunity for training undergraduate and graduate students, and post-doctors TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Preliminary tests point to the potential benefit of tailored MAP for dose reduction in irradiation treatment of fresh produce. The recent approval of irradiation of fresh produce by the FDA makes this type of study even more relevant.
Publications
- Huang, Y., Kim, J., Moreira, R., and Castell-Perez, E. 2008. A Web-Based Information System for MNCP Simulation of Irradiation of Complex-Shaped Foods. Applied Engineering in Agriculture. 24: 233-242
- Gomes, C., Moreira, R., Castell-Perez, Kim, J., and Da Silva, P. 2008. Effects of low-dose electron beam irradiation on quality and safety of Ready-to-Eat Spinach Leaves (Spinacea oleracea). Journal of Food Science. 73: 95-102.
- Kim, J., Moreira, R, and Castell-Perez. 2008. Validation of Irradiation of Broccoli with a 10 MeV Electron Beam Accelerator. Journal of Food Engineering. 4: 595-603.
- Gomes, C., DA Silva, Chimbombi, E., Castell-Perez, E. and Moreira, R.G. 2008.Effects of low-dose electron beam irradiation and storage on quality of broccoli heads (Brassica oleracea Lvar Italica). LWT. 10: 1828-1833.
- Han, J.; Castell-Perez, E. and Moreira, R. 2008. Effect of Food Characteristics, Storage Conditions, and Electron Beam Irradiation on Active Agent Release from Polyamide-Coated LDPE Films. Journal of Food Science.73: 37-43.
- Gomes, C., Silva, P., Kim, J., Castell-Perez, E. Moreira, R. and Sanches-Plata, M. 2008. Enhancing the killing effect of e-beam irradiation with radiosensitization strategies using modified atmosphere packaging (MAP). IFT International Meeting, new Orleans, Louisiana, July.
- Kim, J., Moreira, R., castell-Perez, E. and Huang, Y. 2008. Simulation of pathogen inactivation in cantaloupes (whole and fresh-cut) using electron beam treatment. IFT International Meeting, New Orleans, Louisiana, July.
- Moreno, M., Castell-Perez, M.E., Gomes, C., Da Silva, P., Kim, J., and Moreira, R.G. 2008. Treatement of Cultivated Highbush Blueberries (Vaccinium corymbosum L.) with Electrom Beam Irradiation: Dosimetery and Product Quality. Journal of Food Process Engineering. 31: 155-172..
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: We simulated the dose distribution within a bag of spinach leaves irradiated using a 10 MeV linear accelerator (0.3-1 kGy), to quantify the problem of non-uniform dose absorbed at different parts of the bag and predict death of pathogens. The simulation results confirmed that it is feasible to irradiate baby spinach leaves (up to 1 kGy) to eliminate E. coli 0157:H7 while maintaining the overall quality of the produce. Using an experimental D10 value for E. coli O157:H7 of 0.186 kGy, we simulated the microbial survival distribution within the bag of spinach using both the "target theory and the single-hit inactivation model to solve the general survival equation. In this study, all simulations were based on a bag height of 8 cm resulting in wide energy distribution from the top to the center of the bag. Dose distribution results indicate that due to the bag configuration, higher entrance dose (> 1 kGy) would be required to destroy the pathogens within the leaves. The level of
pathogen inactivation is dependent on the dose applied, with 99% (2-logs reduction) on most areas and 99.999% (5-logs reduction) on both centerline edges of the bag.
PARTICIPANTS: Elena Castell-Perez, Kim Jaegsoon, carmen Gomes, Paula da Silva, Huang jaejoon
TARGET AUDIENCES: target audiences: researchers, students, industry, consumers, produce growers and processors
PROJECT MODIFICATIONS: none
Impacts
1) When conducted properly, e-beam treatment effectively eliminates internalized E. coli O157:H7 cells from spinach leaves. 2) This study showed that when using a 10 MeV linear accelerator, the uniformity of dose distribution in a bag of spinach leaves depends on the arrangement of the leaves inside the bag (relative to the direction of the electron beam). 3) Treatment of leafy vegetables with a 10 MeV LINAC requires a well controlled operating process as well as package design and positioning to ensure reduction of a population of a particular pathogen to the desired level using the lowest dose possible without detriment to produce quality.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
We successfully developed a method to build 3-D geometrical models of food products with image processing techniques based on CT scans. Procedures were developed to produce informative 3-D reconstructions. These 3-D geometrical models strongly support effective Monte Carlo simulations for the accurate calculations of uniform dose distribution on non-homogenous food products. Meats, fruits, vegetables, frozen chicken carcasses, and ready-to-eat meals were obtained from local grocery markets and CT scans conducted with a HD-350E X-Ray CT Scanner. With the CT data, 3-D geometries of the foods were built up through image processing algorithms. A high performance 4 CPU computer was used for the simulation process. MySQL database and PHP were used to develop web applications. MATLAB web server was used to integrate MATLAB programs into web applications. The PVM (Parallel Virtual Machine) is available on the machine to support running the MCNPV5 computing in parallel. The
integration of web browser, MATLAB web server, and a back-end database builds up a 3-tier architecture of the Web-based information system for the MCNP simulation input generation and output visualization.
Impacts
The developed methodology can provide 3-D dose distributions in complex-shaped food products with great accuracy. This new approach should reduce the risk of foodborne illnesses. This technology will help ensure that the U.S. will have a safe and plentiful supply of food.
Publications
- Kim, J., Moreira, R. Huang, Y., and Castell-Perez, M.E. 2006. 3-D dose distributions for optimum radiation treatment planning of complex foods. Journal of Food Engineering, 79(1), 312-321.
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Progress 01/01/05 to 12/31/05
Outputs
A chemical solution composed of paraffin wax, chloroform, and methyl yellow biological indicator was shaped into a solid 3-D apple phantom to determine absorbed dose from low energy e-beams. The purposes of this study were: (1) to determine the most uniform irradiation treatment on apple-phantoms (a complex-shaped target) and GAFCHROMIC HD-810 films using electron beams from a 2 MeV Van de Graaff (VDG) accelerator; (2) to determine dose distribution on apple-phantoms (a complex shaped target) and GAFCHROMIC HD-810 film apple-contours using electron beams from: (1) a 10 MeV Linear Accelerator (LINAC), and (2) X-rays from a 5 MeV LINAC. Irradiation with the VDG accelerator confirmed that tilting the apple-phantom y-axis towards the e-beam source by 90, 45, and 22.5 degrees resulted in more uniform treatment in both the phantom and the HD-810 film. The phantoms were over-exposed at the top and bottom regions when their y-axis was oriented exactly parallel to the e-beam
at 22.5-degrees. The 45-degree orientation ensured uniformity throughout the whole apple surface without overexposing it at the top and bottom regions. In contrast, the 90-degree orientation was in the least effective treatment with the bottom and top regions not receiving any radiation. For a Lucite thickness of 3 cm (target dose of 1.0 kGy), the 10 MeV dual e-beam showed uniform penetration from top to bottom in the apple-contour HD-810 film with a maximum dose of 1.2 kGy located at the top left region of the apple. The methyl yellow apple-contour saturated due to the high absorbed dose compared to its maximum response (0.5 kGy). Nonetheless, the same absorption trend was found with the highest doses located at the top and bottom regions of the apple Irradiation with X-rays penetrated the whole apple phantoms from top to bottom showing excellent lateral uniformity at different penetration depths.
Impacts
The use of phantoms (to represent a complex shaped food) helps calculate and validate dose distribution in complex shaped food products. Results demonstrated that a solid-state 3-D apple-phantom helped to visually determine absorbed dose in the phantom vertical axis of symmetry throughout its periphery.
Publications
- Rivadeneira, R. 2004. DEVELOPMENT OF A CHEMICAL DOSIMETER FOR ELECTRON BEAM FOOD IRRADIATION. M.S. Thesis. Biological and Agricultural Engineering Department, Texas A&M University.
- Rivadeneira, R., Kim, J., Moreira, R.G. and Castell-Perez. 2005. A chemical dosimeter for optimization of electron beam irradiation of foods. IFT International Meeting, New Orleans, July 2005.
- Rivadeneira, R., Moreira, R., Kim, J., and Castell-Perez, M.E. 2005. A 3-D phantom for dose mapping of complex-shaped foods using low energy (2-MeV) electron-beam Irradiation. Radiation Physics and Chemistry. In review
- Rivadeneira, R., Moreira, R., Kim, J., and Castell-Perez, M.E. 2005. A 3-D phantom for dose mapping of complex-saped foods using e-beam and X-rays from a LINAC accelerator. Radiation Physics and Chemistry. In review
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Progress 01/01/04 to 12/31/04
Outputs
Food irradiation technology has the potential for preventions of food safety risks. However, many of the food product and package configurations are highly non-homogeneous with respect to their three-dimensional mass distribution. The objectives of this study were (1) to obtain high-resolution 3-D dose maps in a paraffin apple-phantom using CT scanning and Monte Carlo simulation, and (2) to compare the calculated values with measured one. A paraffin apple-phantom dosimeter, which color changes from yellow to red with an intensity of color proportional to the absorbed dose, was manufactured by casting technique. It was scanned by a CT scanner to obtain its geometry and density data needed for simulation. The dose distribution was calculated using Monte Carlo technique that provided a 3-D dose maps showing maximum and minimum dose regions and the penetration depth. The electron interaction characteristics (total linear stopping power, dose contour, and depth-dose curve)
of the paraffin apple-phantom agreed very well with those obtained with an actual apple. Also, the measured and calculated dose distribution in the paraffin apple-phantom showed good agreement. These results support the validity of the use of the simulation method and the paraffin phantom technique for food irradiation processing.
Impacts
The use of 3-D food phantoms, which mimic the shape and composition of the target real food product, is essential in the validation of dose calculation in irradiated complex-shaped, non-homogeneous food products. The use of food-phantoms can result in a fast and accurate method to design irradiation treatment plan for any food products.
Publications
- Anand, A., R. G. Moreira, J. Henry, T. Good, and G. Cote. 2004. A bio-sensing strategy for the detection of prions in foods. Lebensmittel-Wissenschaft und-Technologie/Food Science and Technology
- Henry, J., A. Anand, M. Chowdury, G. Cote, R. Moreira, T. Good. 2004. Development of a nanoparticle based - surface modified fluorescence assay for the detection of prion proteins. Analytical Biochemistry.ABIO-04-78R1
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Progress 01/01/03 to 12/31/03
Outputs
Our research team has established a knowledge base on the critical gaps in the field of electron beam irradiation technology applications for food safety. Specific information is needed on the doses required to inactivate the common pathogens and the factors that may alter the percentage killed, and the interactions of radiation injury of the pathogen with other treatments (physical or chemical). We conducted an extensive literature search on current problems regarding food safety and electron beam irradiation technology. Little information exists regarding electron beam irradiation on fresh produce quality, dosimetry considerations, and product quality as a function of dose rate. Selected food samples were scanned to obtain multi-sliced Computer Axial Tomography (CAT) scan data. Using this data, the sample geometry was constructed through an image-processing algorithm, i.e. scanning the CAT data. This procedure was applied to all food slices data. After that, a 3-D
geometry was constructed using extrapolation techniques. The CAT scan data were used to describe the product's exact geometry using the image processing . Experimental irradiation tests and simulation were conducted in a phantom apple. The apple was made of paraffin and molded as a red delicious using casting molding techniques. The apple was irradiated using 10MeV electron beam at the E-Beam researcher facility at Texas A&M University. The energy used varied fron 1-3kGy. The simulation studies were carried on using Monte Carlo technique with the MNCP-4C simulator. Image input data (shape and composition) were obtained using CAT scan techniques. The phantom apple was sliced perpendicularly to its y-axis. Radiochromic films were placed around each slice. Changed in the color of the films were correlated to dose values and used to compare with the simulated results.
Impacts
The most important aspect of irradiation treatment planning studies of food products is to be able to describe the geometry and composition of these materials accurately. This information will allow us to precisely calculate the dose distribution in products when defining irradiation treatment for fruits and vegetables. Obtaining a uniform dose in inherently irregular shape objects such as whole produces or fresh-cut package is very difficult. Conventional dose calculation methods do not adequately account for the complex 3-D structure of foods, inhomogeneity corrections, and the lack of secondary electron equilibrium in and around the object. The Monte Carlo method used in this research is the most accurate method for dose calculation in electron beams. In Monte Carlo calculations, the particle tracks or histories are generated by simulating the random nature of the particle interactions with the medium.
Publications
- Han, J.; C Gomes, E. Castell-Perez and R. G. Moreira. 2003. Effects of Low-dose Electron Beam Irradiation on Quality and Shelf-Life of Packaged Romaine Lettuce Hearts. Food Science and Technology. Submitted
- Moreno, M., O. Rodriguez, E. Castell-Perez and R. G. Moreira. 2003. Effect of Electron Beam Irradiation on Product Quality Attributes of Cantaloupes (Cucumis melo, L). International Journal of Food Science and Technology .Submitted
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Progress 01/01/02 to 12/31/02
Outputs
Acrylamide, a potential human carcinogen, appears to form via Maillard reaction from asparagine, free amino acids and monosaccharides; compounds naturally occurring in starch-rich plant-derived foods when processed in high-temperature processes, such as deep fat frying. Deep fat frying is the most used unit operation worldwide. However, little is known about acrylamide generation during frying to identify safe modifications that will clearly prevent or reduce its formation. Fried potato products (potato chips or French fries) may contain 50 to 3500 ppb levels of acrylamide. This project focuses on understanding acrylamide generation during frying and on developing safety operations for frying foods. We are looking to traditional frying as well vacuum frying; a low temperature frying process that we believe has a great impact in the reduction of acrylamide formation in foods. The central hypothesis for the proposed research is that a lower temperature frying process
will ensure safety and product quality. We have formulated this hypothesis based on evidence that suggest that high temperature and long processing time processes enhance the generation of acrylamide in fried potatoes. Also, we have supportive preliminary results that will be detailed in a later section. We have analyzed the acrylamide content of potato chips fried under vacuum and atmospheric conditions in our lab. The method used for acrylamide measurement was a slight modification of the LC/MS/MS protocol developed by FDA. The method uses a Waters C-48 Atlantis HPLC column [isocratic run of 90% water and 10% methanol (0.1% formic acid added)]. Preliminary results showed that potato chips (Variety Superior) fried at 165oC for about 5 minutes in an atmospheric fryer had higher acrylamide content than chips fried in vacuum frying. Overfrying (potato chips fried for 8 min resulting in a darker color) produced even higher acrylamide content. We are still working in the detection method.
However, these preliminary results clearly support our central hypothesis.
Impacts
Outcomes from the proposed research project should provide important insight on the effect of operating conditions, equipment types, and food composition on acrylamide formation during frying. The research proposed in this request is significant, because application of the resultant new knowledge is expected to lead to new approaches that will greatly reduce the risk of acrylamide in fried products. Through an optimized frying process based on the developed methodology, the reduced acrylamide formation and improved quality of fried food products would assure consumers of the safety of fried food.
Publications
- Limanond, B., Castell-Perez, M.E. and Moreira, R.G. 2002. Quantifying Texture Changes in Corn Tortillas due to Staling. Journal of Texture Studies, Volume 33, 1: 35-45
- Limanond, B., Castell-Perez, M.E. and Moreira, R.G. 2002. Modeling Staling of Corn Tortilla. Journal of Food Engineering. 53(3): 237-247.
- Spadaro,V.; D.H. Allen, J.T. Keeton, R.G. Moreira and R. M. Boleman. Biochemical properties of meat and their correlation to tenderness. 2002. Journal of Texture Studies. 33:59-87.
- Garayo, J. and R.G. Moreira. 2002. Vacuum frying of potato chips. J. of Food Engr. 55(2):181-191
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Progress 01/01/01 to 12/31/01
Outputs
Mathematical Modeling of the Electron Transport in an Apple Monte Carlo simulation was used to determine the dose distribution at the surface of an apple irradiated with e-beam generated by a Van de Graaf accelerator (1-2 MeV). The dose distribution was used to develop the best irradiation angle while rotating an irregularly shaped food material (the apple) for uniform surface irradiation. A software package, MCNP (Monte Carlo N-Particle), was used to simulate an electron beam irradiation with a 1.0, 1.5 and 2.0 MeV sources on an apple modeled by inter- connecting two spheres. The apple radii were 4.4 cm (perpendicular to its axis) and 3.6 cm (parallel to its axis) and the volume was divided into small segments for the purpose of calculating energy deposition as a function of angular position and radius. A combination irradiation treatment with the axis of the apple tilted 30deg against and 30deg towards the source irradiation position after one full revolution
resulted in the most uniform dose distribution for the three energy sources tested. Most of the energy in the interior of the apple was deposited by 0.8 cm for the 1.5 MeV. The higher the source energy, the longer the deceleration process, resulting in the gradual deposition of small amounts of energy. The dose distribution oscillates less for each radius as the energy source increases. Oscillations in dose distribution are higher closer to the top and bottom positions (90 and 270deg), and lower near the front center of the apple (180deg). The increase in dose distribution oscillations at the top and bottom of the apple is the result of the irregular surface of the apple. Statistical Modeling of Porous Media Monte Carlo simulation was used as an alternative technique to stochastically model component distribution in a tortilla chip. The components included oil, water, pores and solids. A conditional percolation approach was used to model pore size distribution and predict thermal
conductivity in a tortilla chip fried at 190 C for 60 seconds. The results were simulated using Ensight a Scientist's, plotting tool. The individual components were considered as scalars on a three-dimensional mesh and iso-surfaces were plotted across them. The component clusters were counted and their mean size determined. The clusters were further analyzed for different frying conditions. The model predicted maximum oil absorption in a control tortilla chip (once baked) during the first 10 seconds of frying. Simultaneously, maximum water evaporation was observed during the first 10 seconds of frying. Maximum pore expansion occurred between 30 and 40 seconds of frying.
Impacts
The dose at each point in an object exposed to electrons is effected by the shape and thickness of the ob-ject because electrons are easily attenuated and scattered by the material they pass through. Obtaining a uniform dose in inherently irregular shape objects such as a whole chicken or a prepared meal package is much more difficult. Furthermore, convenience foods such as packaged meals may contain components which require different doses. Conventional dose calculation methods do not adequately account for the complex 3D structure of foods, inhomogeneity corrections, and the lack of secondary electron equilib-rium in and around the object. Monte Carlo transport simulates the behavior of irradiation particles as they interact with atoms in the food during a typical radiation treatment. Results from these simulation helps to setup the irradiation procedure by indicating how to rotate the produce so that the most uniform dose distribution is obtained in the product.
Stochastically modeling a fried product and simulating its three dimensional structure during frying en-able a better control of the frying process. Simultaneously, product quality can be enhanced by a better perceptive of the distribution of the several components (oil, water, air and solids) within the product.
Publications
- Kawas, M.L. and R.G. Moreira. 2001. Effect of degree of starch gelatinization on product quality attributes of tortilla chips during frying. Journal of Food Science. 66(2):195-210.
- Moreira, R.G. 2001. Impingement drying of foods. Symposium in "Advances in Drying Technology in the Food Industry". Journal of Food Engineering.49(4):291-295
- Braud, L., R.G. Moreira and M.E. Castell-Perez. 2001. Mathematical modeling of impigiment drying of corn tortilla. Journal of Food Engineering. 50(3):121-128.
- Moreira, R.G. 2001. Deep-fat frying of foods. In:Food Process Operations - modeling and analysis for design. Editor Irudayaraj, J. Marcel Dekker Inc. New York
- Moreira, R.G. 2001. Automatic Control for Food Processing Systems. Aspen Publishers
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Progress 01/01/00 to 12/31/00
Outputs
A fundamental model was developed to predict the heat and mass transfer that occur during the frying and cooling processes. Semi-empirical correlation were included to account for structural changes, such as shrinkage and expansion due to puffing. A finite element method was used to solve the sets of partial differential equations. The parameters that were studied included water saturation, oil saturation, temperature, and pressure. The higher frying temperature resulted in a faster drying rate and a faster increase in the temperature and pressure of the product. More oil was absorbed at a lower frying temperature. Results showed that thicker tortilla chips absorbed less oil during frying than thinner tortilla chips when fried at the same oil temperature. Oil absorption appeared to seize once the temperature of the product begins to increase and a crust begins to form. The formation of the crust layer led to excessive pressure buildup. Air and vapor trapped inside the
pores began to expand as the temperature increased leading to puffing of the tortilla chip. The expansion of the tortilla chip began at about a water saturation of 0.20. The thickness of the tortilla chip was correlated to increase 100% near the center and progressively less moving away from the center. Shrinkage took place during the first few seconds of frying when the free water (zone III) was removed. The radius of the tortilla chip was reduced by about 9.1%. Further frying led to removal of zone II water, or slightly bound water. At equilibrium, only zone I water, or the most tightly bound water, remained. The cooling temperature had the most influence on oil absorption. The cooling temperature that was nearest to the temperature of the fried product led to the least amount of oil absorption. Oil absorption was assumed to be driven by capillary pressure difference and appeared to slow down as the temperature and pressure approached the ambient conditions. The amount of oil
absorbed was hypothesized to be directly related to the amount of oil that was saturated at the surface during the frying and the cooling process.
Impacts
The development of a comprehensive model to describe the frying of tortilla chips is fundamental in process design, control, and product quality predictions. The simulator has helped in understanding oil absorption mechanisms as affected by pressure buildup, crust formation, shrinkage, and expansion. A 2-D simulation and graphs improved the visualization and better interpretation of the process.
Publications
- Kawas, M.L. and R.G. Moreira. 2000. Characterization of product quality attributes of tortilla chips during the frying process. J. of Food Engineering. 47(2):97-107.
- Singh, S.K., Castell-Perez, M.E. and Moreira, R.G. 2000. Viscosity and Textural Attributes of Reduced-Fat Peanut Pastes. Journal of Food Science, 65(5): 849-853.
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Progress 01/01/99 to 12/31/99
Outputs
Low-fat snack products are the driving force for the drying of potato chips before frying. Superheated steam impingement drying of foods has the advantage of improved energy efficiency and product quality. The temperature profile, drying curves, and the physical properties (shrinkage, crispiness, microstructure and viscosity) of tortilla chips dried at different superheated steam temperatures and heat transfer coefficients were evaluated. Steam from the physical plant was heated by a heater controlled by a PID. The drying experiments were conducted with steam impinging on the top and bottom surfaces of the sample from the two nozzles. The diameter of the nozzles was about 15 mm and the distance from the exit of nozzle to the sample was about 90 mm, resulting in a ratio of 6.0 to assure the highest heat transfer efficiency under corresponding conditions. The samples were placed within a mesh wire during the drying experiments to avoid curving. The average moisture
content of the samples was measured by removing the samples from the steam every 1 minute and weighed on a digital scale, the weight measurements took about 10 seconds. The weight of the dry matter of the sample was determined by the convection oven method at 105C for 24 hours. The volume change of the samples was measured by volume displacement method. Texture of tortilla chips was determined using the Texture Analyzer (TA-XT2, Texture Technology Corp.) with a frame point beam device. The probe traveled at 0.2 mm/s. From the rupture test, the modulus of deformation (slope of the curve from the beginning of the compression to the fracturability point) was calculated. The structure of the tortilla chips was analyzed by Environmental Scanning Electron Microscope(ESEM, model E-3, Electroscan Corp.) with an accelerating voltage of 20 kV. The center part of the tortilla sample was cut to a small piece and mounted on aluminum stubs with conductive adhesive. The cross section of the sample
was viewed in the same area on each sample. Results indicated that the steam temperature had greater effect on the drying curve than the heat transfer coefficient. The microstructure of the samples after steam drying showed that higher steam temperature resulted in more pores and coarser appearance. The modulus of deformation and the shrinkage of potato chips highly correlated with the moisture content. A higher steam temperature caused less shrinkage and a higher modulus of deformation. The pasting properties showed that samples dried under higher steam temperature and higher heat transfer coefficient gelatinized less during drying and had a higher ability to absorb water.
Impacts
Studies on new methods to dehydrate foods will help to improve product quality and process efficiency. Results have shown that this drying method is more efficient and the quality of the product is improved by reducing oxidation and improving the cooking aspects of starch based products. This process could be useful as a pre-frying method for snack products. It is expected that less oil would be absorbed during frying when a product is baked using superheated impingement drying before frying.
Publications
- Emesih, G.C., R.G. Moreira and M.A. Barrufet. 1999. Evaluation of modified starches for improved oil recovery. Applied Engineering in Agriculture. 15(3):237-242.
- Murano, E.A.; P.S. Murano, R.E. Brennan, K. Shenoy and R.G. Moreira. 1999. Application of high hydrostatic pressure to produce safe and long-lasting fresh pork sausage. J. Food Protection. 62(5):480-483.
- Suhendro, E.L., H.D. Almeida-Dominguez, L.W. Rooney, R.D. Waniska and R.G. Moreira. 1999. Use of extensibility to measure corn tortilla texture. Cereal Chem. 76(4):536-540.
- Huang, M.; R.G. Moreira, and E. Murano. 1999. Use of hydrostatic pressure to produce high quality and safe fresh pork sausage. Submitted to J. of Food Processing and Preservation. 23(4):218-220.
- Book: Moreira, R.G.; Castell-Perez, M.E. and Barrufet, M.A. 1999. Deep-Fat Frying: Fundamental and Applications. Aspen Publisher. Boston, MA.
- Thesis: Miranda-Lopez, R. 1999. Effects of some anti-staling additives, pH and storage on the staling of corn tortillas. Ph.D. degree in Food Science and Technology, Texas A&M University.
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Progress 01/01/98 to 12/31/98
Outputs
Staling is one the most important quality loss characteristics of corn tortilla in shelf life studies. It can be regarded as the loss of viscoelastic properties due to changes in the starch structure. Ways of mathematically predicting staling characteristics of food products will improve the quality and shelf life of these products. Table tortillas were prepared my mixing nixtamilized flour and water following the procedures described elsewhere. They where allowed to rest at ambient conditions from 1 to 6 hours and from 1 to 5 days. For both conditions, the tortillas were stored at room temperature inside polyethylene bags. Stress relaxation (objective method) and rollability test (subjective method used in the industry) were used to detected changes in the samples texture properties. Results showed that moisture content of the tortilla chips did not change during the resting time (1-5 days) and was equal to 44.3+0.8. Tortillas stored for 6 hours became less easy to
handle, cracking in one side of the surface. Between 1 and 2 hours the quality of the tortillas were at their best. After one day of storage tortillas cracked on both sides and became unrollable after 5 days of storage. Stress relaxation tests indicated that the tortillas stiffness increased linearly from 1 to 6 hours of storage. After 1 day of storage, stiffness increased more pronouncedly to a maximum value after 4 days of storage. The product behave more like an elastic solid with a reduction in energy dissipated as the storage time increased
Impacts
(N/A)
Publications
- Moreira, R.G. and M.A.Barrufet. 1998. A new approach to describe oil absorption in fried foods: a simulation study. Journal of Food Engineering. 35:1-22.
- Li, Y.B.; Seyed-Yagoobi, J. ; R.G.Moreira, R.G. and R. Yamsaengsung. 1998. Superheated steam impingement drying of tortilla chips. Drying Technology.
- Tsue-Er Lo, R.G. Moreira and M.E. Castell-Perez. 1998. Rheological properties of corn meal dough. Food Science and Tech. Intern.
- Tsue-Er Lo, R.G. Moreira and M.E. Castell-Perez. 1998. Modeling product quality during twin-screw food extrusion. Transactions of the ASAE.
- Tsue-Er Lo, R.G. Moreira and M.E. Castell-Perez. 1998. Effect of operating conditions on melt rheological characteristics during twin-screw food extrusio. Transactions of the ASAE.
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Progress 01/01/97 to 12/31/97
Outputs
The effects of high hydrostatic pressure (HHP) on the survival of microorganisms and quality changes of fresh pork sausages were investigated. Pork sausage inoculated with Listeria monocytogenes was prepared and subjected to HHP at 414 and 552 MPa for various time intervals to examine pressure effects on inactivation of bacteria and quality changes. At a pressure of 414 MPa and 50C for 2 min, the microorganisms in fresh pork sausages were completely inactivated. Partial discoloration of meat was observed after 10 min of pressurization above 414 MPa. The moisture content was not affected by pressure. The sausages increased in hardness with an increase in the pressure applied. The pressure-treated sausages were generally darker in color as compared with the heat-treated sausages. The optimal pressure/temperature/time conditions that resulted in minimum quality changes with microbiologically safe fresh pork sausages was 414 MPa and 50C for 2 min. The mechanism of oil
absorption of tortilla chips during cooling was analyzed using capillary pressure theory. The experimental and theoretical results obtained with this mechanistic model agreed well. Computer simulations were made to determine the effect of different process conditions on the final product oil content. The results show higher oil content for tortilla chips with higher initial moisture content, smaller radius, lower cooling air temperature, and higher interfacial tension. Both frying and cooling conditions are critical to the final product quality of deep-fried products. The frying process was simulated by applying energy and mass balance equations to a single chip and a batch of tortilla chips. The temperature, moisture content, and oil content were calculated as a function of frying time. Finite difference technique was used to solve the set of partial differential equations. The temperature of the chips and the temperature of the oil during frying were measured. Comparisons between
predicted and observed results showed that the model successfully simulated the batch frying processes for tortilla chips. The good agreements also validate the frying mechanism proposed by this study. Hydrolyzed polyacrylamides (HPAM) and Xanthan gum products have been widely used in recovery processes. However, limitations to these products have prompted a search for cheaper, more stable, and environmentally friendly alternatives. The rheological, chemical and petro-physical properties of waxy corn and tapioca starch biopolymers were evaluated to test their effectiveness as water control agents in oil recovery applications. The starches were used in concentrations ranging from 0.2 to 3%, prepared in 0 to 6% NaCl concentrations, heated to 95C, and tested at various temperatures. Starch biopolymer flooding showed an increase of 6 - 8% in cumulative oil production over polyacrylamide flooding. It demonstrated superior performance and economic benefits in using starch biopolymers rather
than polyacrylamides in the simulated reservoir conditions.
Impacts
(N/A)
Publications
- Moreira, R.G., Sun, X. and Chen, Y. 1997. Factors affecting oil uptake in tortilla chips in deep-fat frying. J. of Food Engineering. 31(4):485-498.
- Lujan, F.J., R.G. Moreira and J. Seyed-Yagoobi. 1997. Impingement drying of tortilla chips. Drying Technology. 15(3&4):881-897.
- Schonauer, S. and R.G. Moreira. 1997. Dynamics analysis of on-line product quality attributes for automation of food extruders. Food Science and Technology International. 12: 1210-1220.
- Lujan, F.J., R.G. Moreira. 1997. Effects of different drying processes on oil absorption and microstructure of tortilla chips. Cereal Chemistry. 74(3):216-223.
- Brescia, L. and R.G. Moreira. 1997. Modeling and control of a continuous frying process: I Dynamic analysis and system identification. Trans. of Chem. Engr. 75(c): 3-11.
- Brescia, L. and R.G. Moreira. 1997. Modeling and control of a continuous frying process: II Control development. Trans. of Chem. Engr. 75(c):12-20.
- Lujan, F.J. and R.G. Moreira. 1997. Reduction of oil in tortilla chips using impingement drying. Food Science and Technology. In press.
- Chen, Y. and R.G. Moreira. 1997. Modeling of a deep-fat frying process. Trans. of Chem. Engr. 75(c): 181-190.
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Progress 01/01/96 to 12/30/96
Outputs
Biomechanical studies were performed to characterize mechanical behavior of 16 raw post rigor bovine Longissimus dorsi muscles. Linear viscoelastic properties were measured in terms of relaxation moduli Eijkl using a standard stress-relaxation technique at 3% strain. A macromechanical approach was taken to solve a boundary value problem that partially mimicked a simplified model of a 1st chew cycle of the human masticatory process. Mechanical parameters such as stiffness & total energy dissipated were calculated & correlated to tenderness traits. Stiffness & total energy dissipated were highly correlated to overall tenderness (R2=0.74 & R2=0.83). Starch samples were used to prepare 1% & 3% solutions (mixed with 3% salt (NaCl)). The Brookfield viscometer DVIII (models LV & RV) were used to determine the rheological characteristics of these starches under steady shear conditions. Starch solutions behaved as Newtonian (<1% samples) & pseudoplastic (>3% samples) fluids.
Corn starches exhibited thixotropy, lower shear-thinning characteristics, & very good miscibility in water. Starches were stable in various saline environments. Low fat tortilla chips were produced using impinging hot air drying techniques. Results indicated that tortilla chips drying rate was mostly affected by air temperature; texture was crispier at higher air temperatures; shrinkage was higher at lower convective heat transfer coefficient; & microstructure looked smoother at higher air temperature.
Impacts
(N/A)
Publications
- Schonauer, S. and R.G. Moreira. 1996. A variable restrictive valve as an extra independent control variable for food extrusion process. Food Science and Technology International. 2: 241-248
- Tseng, Y., R.G. Moreira and X. Sun. 1996. Total frying-use time effects on soybean oil deterioration and on tortilla chip quality. Int. J. of Food Science and Techn. 31: 287-294.
- Lujan, F.J., R.G. Moreira and J. Seyed-Yagoobi. 1997. Impingement drying of tortilla chips. Drying Technology. 15(3): 120-130.
- Schonauer, S. and R.G. Moreira. 1996. Product quality adaptive control system for a food extruder. Proceedings of the AIChE Conference on Food Engineering - Chicago, Il.
- Tsue-Er Lo and R.G. Moreira. 1996. Product quality modeling of a twin-screw extrusion process. IFT International Meeting - New Orleans, LO.
- Brescia, L.E. and R. G. Moreira. 1996. Development of a GPC Control strategy for a continuous fryer based on product quality attributes. IFT International Meeting.
- Moreira, R.G. and M.A. Barrufet. 1996. Spatial distribution of oil after deep-fat frying from a stochastic model. J. of Food Engineering. 27(2):205-220.,
- Sun, X. and R.G. Moreira. 1996. Relationships between proton relaxation time andfree fatty acids and polar materials of degraded soybean oil. J. of Food Processing and Preservation. 20: 157-167.
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Progress 01/01/95 to 12/30/95
Outputs
Relationships between operating variables (screw speed, water rate, barrel temperatures, & feed rate), process variables (product-die temperature, product pressure, residence time) & PQA of a twin-screw extrusion process was modeled using multi-linear regression. PQA is less sensitive to the change in operating variables. Viscosity decreased as an extra paddle was added to the screw configuration. Dynamics of a continuous frying process was modeled & a controller developed to automatically control product quality attributes on-line. The process was modeled using ARX model structure. A Generalized Predictive Controller (GPC) was used. Inputs were the oil temperature (F), submerger conveyor speed (%), & the takeout conveyor speed (%). Outputs were the oil content (% wb) & moisture content (% wb). Frying & cooling processes of tortilla chips were simulated by developing energy & mass balances in a control volume of a bed of tortilla chips being fried. Finite difference
technique was used to solve the set of partial differential equations. Effects on final oil content were analyzed. Tortilla chips oil content was affected by moisture content & particle size distribution. High initial moisture content & larger particle size resulted in high final oil content. Final oil content was not affected by oil quality. Tortilla chips fried in used oil had more oil acumulated at the surface than chips fried in fresh oil.
Impacts
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Publications
- Woreira, R.G.; J. Palau and X. Sun. 1995. Simultaneous heat and mass transfer during deep fat frying of tortilla chips. J. of Food Proc. Eng. 18:307-320.
- Moreira, R.G. and M.A. Barrufet. 1995. Spatial distribution of oil after deep-fat frying from a stochastic model. J. of Food Eng. in-press.
- Moreira, R.G. and J. Palau. 1995. Deep-fat frying of tortilla chips- an engineering approach. J. of Food Tech. 49(4): 146-150.
- Moreira, R.G., J. Palau and V. Sweat. 1995. Thermal and physical properties of tortilla chips as a function of frying time. J. of Food Proc. and Pres. 19:175-189.
- Moreira, R.G., T. Lo and M.E. Castell-Perez. 1995. Rheological changes in cooked corn meal dough to differences in moisture content. Food Sci Tech Inter. 1:41-45.
- Schonauer, S. and R.G. Moreira. 1995. Development of a fixed-GPC controller for a food extruder based on PQA- Part I: System identification . Trans Inst Chem Eng. (In press).
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Progress 01/01/94 to 12/30/94
Outputs
We developed an automatic control for a food extrusion process. The system consists of a fixed multivariable feedback model predictive controller. Collet color is controlled by manipulating the feed rate, water rate, and screw speed. The control system was implemented on a pilot-size food extruder. The controller performed better than the uncontrolled response compared to its ability to for tracking and disturbance rejection performance. We have studied a new approach to determine the elongational viscosity of cooked corn dough. The method was able to detect the effect of moisture content and corn meal characteristics on viscosity. We proposed a model of the viscosity of the extruded as a function of extrusion operating conditions. This model will be used to in a control system for food extrusion. Studies are carried on in the development of a feedforward-feedback controller to reduce the effect of feed inconsistency on the process output. An adaptive control system
will be developed and compared to the fixed control. In the area of deep-fat frying of tortilla chips, we used ESEM technique to describe the effect of pre-frying treatments (not cooked, cooked, and frozen) on the quality attributes of tortilla chips. Oil content increased as initial moisture content decreased. In a addition, we developed a new method to determine the amount of oil at the surface and inside the chips.
Impacts
(N/A)
Publications
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