17A-5 |
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E. D. WILSON1, C. W. Seo1, A. Shahbazi2, and S. A. Ibrahim1. (1) Food Science & Nutrition Program, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 171-B Carver Hall, Greensboro, NC 27411-1064, (2) Bioenivromental Engineering Program, North Carolina A&T State Univ., Dept. of Natural Resources & Environmental Design, Carver Hall, Greensboro, NC 27411-1064 In recent years, because of their reported health benefits, the dairy industry has begun incorporating probiotic cultures into many products such as yogurt and cheese. However, in order to be beneficial, the cultures have to remain live and active at the time of consumption. The objective in this research was to determine the survival and growth of probiotic bifidobacteria and Lactobacillus reuteri in commercially-available sour cream. Fresh sour cream samples were obtained from a local market and inoculated with one of the following probiotic strains: L. reuteri (MM 2-3 and MM 7) and B. longum (ATCC 5708 and NCFB 2254) to obtain a final inoculum level of 107cfu/ml. The sour cream samples were then mixed thoroughly and refrigerated at 4 °C for 2 weeks. The samples were analyzed for viable bacterial count using modified BIM 25 agar to enumerate bifidobacteria and MRS agar supplemented with 50 mg/ml vancomycin to enumerate lactobacillus. Our results show that although bacterial counts decreased, the products contained an average 5.0 x 105 cfu/ml of viable probiotics after 15 days of storage. Results also show significant differences (P < 0.05) among the tested strains during the storage period. L. reuteri MM 2-3 shows a slight decline although it was not significant over the storage period. Both B. longum strains had two log reduction while L. reuteri MM 7 had one log reduction over the storage period. Our results show that the concept of using sour cream as a probiotic carrier is proved feasible.
Session 17A, Dairy Foods: Cheese and microbiology
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