88D-25 |
Survival of Bifidobacterium longum in simulated gastrointestinal juices |
Y. CHANG1, K. Adhikari, and A. Mustapha. (1) Department of Food Science, University of Missouri-Columbia, 256 WCS Wing Eckles Hall, Columbia, MO 65211 Bifidobacteria are probiotic bacteria that have been shown to improve the microbial balance in the human gut. However, they are sensitive to low pH and, thus, cannot survive in the human stomach which has a pH of 1.8 - 2.0. In order for the cells to exert the beneficial effects, it is important to ensure their safe delivery to the human colon. The study was done to determine the survival of microencapsulated bifidobacteria and non-encapsulated bifidobacteria with lactulose, inulin and fructooligosaccharide, added to yogurt, when exposed to simulated human digestive juices. Microencapsulation with k-carrageenan was carried out on Bifidobacterium longum B6. The media used were simulated gastric, bile, and pancreatic juices. Plain yogurt containing encapsulated bifidobacteria, and non-encapsulated bifidobacteria with or without the bifidogenic factors were incubated individually, in each juice or in a mixture of the juices at 37°C for 3 h and 6 h, respectively. Cell enumeration was done on lithium chloride-sodium propionate agar. Experiments were replicated three times and data statistically analyzed using SAS. No significant reduction (P < 0.05) in cell numbers was found in the individual gastric and pancreatic juices for all five treatments. The log reduction of microencapsulated bifidobacteria was 0.628 in bile juice after 3 h and 0.649 in the mixture juice after 6 h of incubation. The log reduction of non-encapsulated bifidobacteria with inulin, FOS, and lactulose was 2.783, 3.006, and 2.117, respectively, in bile juice after 3 h of incubation. In the mixture, the log reduction of non-encapsulated bifidobacteria with inulin, FOS, and lactulose was 3.556, 2.522, and 2.397, respectively, after 6h of incubation. These results showed that microencapsulation and not bifidogenic factors, protect the bifidobacteria from gastrointestinal juices, in vitro.
Session 88D, Food Microbiology: General
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