INFLUENCE OF SPIRULINA PLATENSIS BIOMASS ON MICROBIOLOGICAL VIABILITY IN TRADITIONAL AND PROBIOTIC YOGURTS DURING REFRIGERATED STORAGE

摘要

The effect of adding Spirulina platensis on the viability of a yogurt starter and Bifidobacterium animalis was assessed during 28 days of refrigerated storage. Four types of yogurts were manufactured: The control yogurt; yogurt containing S. platensis; yogurt containing B. animalis; yogurt containing S. platensis and B. animalis. On average, the survival rate of Streptococcus salivarius ssp. thermophilus was better than those of both Lactobacillus delbrueckii ssp. bulgaricus and B. animalis. S. platensis biomass significantly decreased the viability of S. thermophilus but increased the viable cell counts of L. bulgaricus in both traditional and probiotic yogurts. The stability of B. animalis, on average, remained statistically constant throughout the refrigerated storage period in probiotic algal yogurt compared to probiotic non-algal yogurt. It was also shown that probiotic algal yogurt has a shelf-life of one month with a viable Bifidobacterium cell count of at least 6 log cfu g(-1).