71A-44 |
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A. L. GANDY, C. H. White, J. C. Wilson, M. W. Schilling, and P. C. Coggins. Dept. of Food Science, Nutrition and Health Promotion, Mississippi State Univ., 110 Herzer Bldg., Mailstop 9805, Mississippi State, MS 39762-9805 The shelf life of milk is considered the length of time from processing/packaging until the product becomes unacceptable to the consumer. Therefore, the most accurate measure in determining milk shelf life is sensory testing of the milk daily until the point of rejection. Many microbiological tests exist for predicting the shelf life of pasteurized milk. The Moseley test is one test that has been generally accepted in shelf life evaluations of pasteurized milk; however, the Moseley test requires 7 to 10 days to complete, which obviously is not desirable as a predictor of shelf life. Newer methods that are more rapid have been developed to overcome these restraints. One of these is the MicroFoss (BioSys) instrument. MicroFoss is a computerized instrument designed to rapidly detect microbial contamination within 48 hr of pasteurization. The objective of this study was to determine the relationship between MicroFoss detection times and the shelf life of pasteurized milk. Daily sensory evaluations were performed by trained judges to determine the shelf life of each milk sample. Three microbiological tests—the Moseley test, the BioSys TVC (total viable count) test, and the BioSys GN (gram negative count) test—were performed on the milk samples. Results of the study showed significant (P < 0.05) correlation (R=0.825) between shelf life and BioSys TVC detection times. The study also indicated correlation (P < 0.05) between shelf life and the Moseley test (R=-0.643). However, the study did not reveal significant correlation between BioSys GN detection times and shelf life (P > 0.05). These data suggest optical sensor technology may have significant applicability in this field as an indicator of pasteurized milk shelf life. The use of this technology would allow the dairy industry an easier, more rapid method for predicting milk shelf life. However, more research is needed to maximize the predictive abilities of BioSys technology.
Session 71A, Dairy Foods: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |