99D-11 |
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D. P. MONTOYA, T. D. Boylston, and A. F. Mendonca. Dept. of Food Science & Human Nutrition, Iowa State Univ., 2312 Food Sciences Bldg., Ames, IA 50011-1061 The health-promoting benefits of probiotic bacteria have contributed to an interest in the incorporation of these bacteria into dairy products. These bacteria grow best in an anaerobic environment at neutral pH. The challenge for the development of dairy products with probiotic bacteria is to provide an environment that is optimal for their viability, so that the bacteria will be present at or above the therapeutic minimum (106 colony-forming units (cfu)/gram) needed to provide nutritional benefits. The objective of this study was to evaluate the viability of probiotic bacteria in a Swiss cheese environment and the effect of these bacteria on flavor, using a cheese curd slurry model system. Bifidobacteria breve, B. longum, B. infantis, and Pediococcus acidilactici were inoculated into cheese slurry prepared from unripened Swiss cheese and incubated anaerobically for 7 and 10 days. Microbial counts of the probiotic bacteria and total lactic acid bacteria were determined. Volatile flavor compounds, free amino acids, and titratable acidity were analysed. All four probiotic bacteria were present above the therapeutic minimum (6.3 x 108 – 1.7 x 1010 cfu/g) following the 10-day storage period. B. breve and B. longum demonstrated the highest growth in the model systems. The addition of the probiotic bacteria did not inhibit the growth of the normal cheese background flora. Profiles of volatile flavor compounds, free amino acids, and titratable acidity were not significantly altered by the incorporation of the probiotic bacteria. Probiotic bacteria can survive an environment typical of Swiss cheese without adversely affecting the flavor quality, suggesting the potential for development of a Swiss cheese with improved nutritional benefits. Incorporation of probiotic bacteria into Swiss cheese would continue the evolution of new probiotic cheeses with improved nutritional and physiological qualities.
Session 99D, Food Microbiology: General
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