Survival of Lactobacillus acidophilus and Bifidobacterium bifidum in commercial yoghurt during refrigerated storage

Samples of five brands of commercial yoghurt were obtained directly from the processors and enumeration of viable Lactobacillus acidophilus and Bifidobacterium bifidum and determination of pH was carried out at three-day intervals over a five-week period. Three of the five products contained 107-108 g-1 viable cells of L. acidophilus, whereas the other two products contained ≤ 105 of this organism initially. Similarly, the initial count of B. bifidum was 106-107 g-1 in two of five products, while the viable numbers of this organism were ≤ 103 in the other three products. All the products showed a constant decline in the viable count of L. acidophilus and B. bifidum during storage. Initial pH values ranged from 4.07 to 4.36 and these declined after five weeks of storage to pH 3.8-4.26. © 1995.link_to_subscribed_fulltex