Assessment of Vitamin B2 and B3 Contents of Conventional and Probiotic Yogurt after Refrigeration by High Performance Liquid Chromatography.

BACKGROUND: Milk and dairy products are natural sources of B group vitamins in the human diet. This study was carried out to compare the ability of probiotic and conventional microorganisms of yogurt to influence the status of vitamin B2 (riboflavin) and vitamin B3 (niacin) during refrigeration. METHODS: After preparation of conventional and probiotic yogurt, all samples were stored at 4°C, and the content of B2 and B3 vitamins was assessed on first, third and seventh day of refrigeration. Vitamins B2 and B3 were analyzed in samples using high-performance liquid chromatography followed by fluorescence detection and ultraviolet detection, respectively. Data was analyzed using SPSS version 18 (SPSS Inc., Chicago, USA). RESULTS: Vitamin B2 content of probiotic yogurt samples was significantly higher than the control samples on all experiment days (P< 0.05). Significant differences between content of vitamin B3 in conventional and probiotic yogurt were found only on the seventh day of refrigeration (P< 0.05). CONCLUSION: This study showed that using probiotic strains from yogurt manufacturers might provide higher B2 and B3 vitamin content provided yogurt is refrigerated for storage. [ABSTRACT FROM AUTHOR]