36E-98 |
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K. M. CROWE, A. A. Bushway, R. J. Bushway, and R. A. Hazen. Dept. of Food Science and Human Nutrition, Univ. of Maine, 5735 Hitchner Hall, Orono, ME 04469 The fruit and vegetable industry is faced with escalating microbial challenges as governmental agencies like the FDA Center for Food Safety and Applied Nutrition continue to mandate action plans to minimize foodborne illness. In addition, chemical contamination concerns are arising over the use of chlorine as an antimicrobial agent; therefore, the validation of alternative postharvest treatments for minimally processed fruits and vegetables is imperative for companies relying on chlorine to meet microbial challenges. The objectives of this research were to evaluate the efficacy of hydrogen peroxide and UV treatments in reducing microbial populations and pesticide residues on lowbush blueberries (Vaccinium angustifolium) destined for Individually Quick Frozen (IQF) or fresh pack markets and to isolate and identify the predominant bacterial flora on lowbush blueberries in order to evaluate their susceptibility to postharvest treatment applications. Treatments evaluated in this study included 1% hydrogen peroxide, 1% hydrogen peroxide/UV, and continuous wave UV. Appropriate microbiological and analytical markers were employed for analyzing treatment effectiveness. Pseudomonas fluorescens and Enterobacter agglomerans were isolated and identified as the 2 predominant bacterial species on lowbush blueberries. Because species from both genera have been shown to produce biofilms, both organisms may be protected from commercial disinfectants, namely chlorine. Research is currently underway to evaluate the antimicrobial susceptibility of these organisms to hydrogen peroxide and UV. Analysis of 1% hydrogen peroxide- and UV-treated blueberries both resulted in bacterial and yeast reductions of up to 1.5- log after 60 and 120 seconds. After only 60 seconds, photochemical oxidation treatments resulted in a 4-log reduction in bacterial counts. In addition to antimicrobial effectiveness, pesticide oxidation in these samples was minimal compared to chlorine-treated samples. Because phosmet oxidation yields an oxygenated analogue considered by the EPA to be more toxic than phosmet, hydrogen peroxide and UV treatments exhibit maximum progress toward the industry's goal in producing safe, high quality products for IQF and fresh pack markets.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |