Survival of Lactobacillus acidophilus and Bifidobacterium animalis ssp lactis in stirred fruit yogurts

The effect of commercial fruit preparations (mango, mixed berry, passion fruit and strawberry) on the viability of probiotic bacteria, Lactobacillus acidophilus LAFTI (R) L10 and Bifidobacterium animalis ssp. lactis LAFTI (R) B94 in stirred yogurts during storage (35 days) at refrigerated temperature (4 degrees C) was evaluated. The results showed that addition of either 5 or 10 g/100 g fruit preparations had no significant (p > 0.05) effect on the viability of the two probiotic strains except on L. acidophilus LAFTI L10 yogurt with 10 g/100 g passion fruit or mixed berry. After the addition of fruit preparation, 96% of the yogurts incorporated with fruit preparation did not exhibit a greater loss in the viability of probiotic bacteria compared to plain yogurt during the storage period. A correlation between the post-storage pH in yogurts and the survival of probiotic bacteria was observed. All the yogurts, however, contained the recommended levels of (10(6)-10(7) cfu/g) probiotic bacteria at the end of 35-day shelf life. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.