2012 Annual Report
Some soft fruits such as tree-ripe apricots cannot be washed without damaging quality. Studies were conducted to evaluate the efficacy of ultraviolet light (UV-C) for inactivation of Salmonella and E. coli O157:H7 on tomato and apricot. Both Salmonella and E. coli O157:H7 populations decreased with increased doses of UV. Results suggest that a 10-second UV-C treatment can reduce 99% of Salmonella spp. and E. coli O157:H7 inoculated onto tomatoes or apricot. Salmonella exhibited slightly higher resistance to UV-C compared with E. coli O157:H7. In addition, UV light in combination with liquid phase ozone (1.4 parts per million) reduced 99.99% of Salmonella in an agitated system with surging bubbles.
Antimicrobial coatings with edible and non-edible polymers and natural antimicrobials were developed for inactivating pathogens on shell eggs. Results show that the antimicrobial coatings were able to reduce up to 99.9999% of Salmonella cells on eggs. There was no re-growth of the pathogen on eggs after coating treatments and during the 28 days’ storage at 7 Degrees C. Results also indicated that the coatings were able to reduce the weight loss of eggs during storage at 7 or 4 Degrees C.
Furan is a potential human carcinogen. The formation of furan was studied in model food systems as affected by heating, ultraviolet, and gamma radiation. Fatty acids and sugars as possible procurers of the compound were further investigated. Results suggest that changes in food composition would influence furan formation as a result of thermal and non-thermal processing.
Based on one survey, one eighth of shrimp samples in the U.S. market is contaminated with L. monocytogenes, a pathogen causing listeriosis. The antimicrobial effects of ozone, antimicrobial coating, and cryogenic freezing, used alone or in combination, on survival of Listeria innocua (a surrogate of L. monocytogenes) on shrimp were investigated. Results indicated that antimicrobial coating in combination with cryogenic freezing reduced more than 99.999% of L. innocua and natural bacteria.
The antimicrobial activity of three essential oils and their major components were evaluated as a gaseous treatment to reduce Salmonella Typhimurium on tomatoes. Texture, color, vitamin C, and lycopene contents of tomatoes were also analyzed after treatments. Results showed that treatment with gaseous cinnamon and oregano essential oils reduced Salmonella on tomatoes by 99.99% and maintained quality of the fruit.
Jin, Z.T., He, Y. 2012. Antibacterial activities of magnesium oxide (MgO) nanoparticles against foodborne pathogens. Journal of Nanoparticle Research. 13:6877-6885. Chen, W., Jin, Z.T., Gurtler, J., Geveke, D.J., Fan, X. 2012. Inactivation of Salmonella on whole cantaloupe by application of an antimicrobial coating containing chitosan and allyl isothiocyanate. International Journal of Food Microbiology. 155:165-170. Dong, X., Dong, M., Lu, Y., Turley, A., Jin, Z.T., Wu, C. 2011. Antimicrobial and antioxidant activities of lignin from residue of corn stover to ethanol production. Industrial Crops and Products. 34(3):1629-1634. Fan, X., Guan, W., Sokorai, K.J. 2012. Quality of fresh-cut iceberg lettuce and spinach irradiated at doses up to 4kGy. Journal of Radiation Physics and Chemistry. 81:1071-1075. Fan, X., Lee, E.J., Ahn, D. 2011. Volatile sulfur compounds in foods as a result of ionizing radiation. In: Qiang, M., Fan, X., Mahattanatawee, K., editors. American Chemistry Society Book Chapter. Book chapter for ACS Publications. Washingnton, DC: American Chemical Society. p. 243-258. Li, W., Li, X., Fan, X., Tang, Y., Yun, J. 2012. Response of antioxidant activity and sensory quality in fresh-cut pear as affected by high O2,active packaging compared with low O2 packaging. Food Science and Technology International. 18:197-205. Li, X., Yun, J., Fan, X., Xing, Y., Yao, T. 2012. Effect of 1-methylcyclopropene and modified atmosphere packaging on chilling injury, and antioxidative defensive mechanism of sweet pepper. African Journal of Biochemistry Research. 10:6581-6589. Mukhopadhyay, S., Ukuku, D.O., Phillips, J.G., Juneja, V.K. 2012. Survival and growth of Salmonella Enteritidis in membrane processed liquid egg white with pH, temperature and storage conditions as controlling factors. Food Microbiology. 75(7):1219-1226. Mukhopadhyay, S., Ramaswamy, R. 2011. Application of emerging technologies to control Salmonella in foods: a review. Food Research International. 45:666-677 Jin, Z.T., Gurtler, J. 2012. Inactivation of Salmonella on tomato stem scars by edible chitosan and organic acid coatings. Journal of Food Protection. 75(8):1368-1372. Gurtler, J., Jin, Z.T. 2012. Propyl paraben sensitizes heat-resistant Salmonella Enteritidis and Oranienburg to thermal inactivation in liquid egg albumen. Journal of Food Protection. 75(3):443-448. Yun, J., Li, X., Fan, X., Yao, T., Xiao, Y., Wan, S. 2012. Effect of gamma irradiation on microbial load, physicochemical and sensory characteristics of soybeans (Glycine max L. Merrill). Journal of Radiation Physics and Chemistry. 81:1198-1202. Yadav, M.P., Strahan, G.D., Mukhopadhyay, S., Hotchkiss, A.T., Hicks, K.B. 2011. Fomation of corn fiber gum-milk protein conjugates and their molecular characterization. Food Hydrocolloids Journal. 26:326-333. Ukuku, D.O., Onwulata, C.I., Mukhopadhyay, S. 2012. Behavior of Escherichia coli bacteria in whey protein and corn meal during twin screw extrusion processing at different temperatures. Journal of Food Processing and Technology. 3(4):1000150. Tomasula, P.M., Mukhopadhyay, S., Datta, N., Porto Fett, A.C., Call, J.E., Luchansky, J.B., Renye Jr, J.A., Tunick, M.H. 2011. Pilot-scale crossflow-microfiltration and pasturization to remove spores of Bacillus anthracis (Sterne) from milk. Journal of Dairy Science. 94:4277-4291.