Relative bioavailability of riboflavin in cows' milk and fermented milk using rat bioassay

Abstract

Abstract Bioavailability of riboflavin from cows' milk and fermented milk was assessed using riboflavin-depleted rats. The fermented milk was prepared using Lactococcus lactis subsp. lactis, and cremoris and Propionibacterium shermanii as starter cultures. Rats were depleted of riboflavin by feeding a riboflavin-free diet for 30 days. At this stage, hepatic riboflavin and erythrocyte glutathione reductase (EGR) activity decreased significantly (P Relative bioavailability (RBV), relative to pure vitamin, of riboflavin from milk and fermented milk was determined by slope ratio statistics using multiple linear regression with hepatic riboflavin, EGR activity and AC on FAD addition as response criteria. RBV for milk and fermented milk were 144 and 161% with hepatic riboflavin as a response criterion, 135 and 154% with EGR activity as a criterion and 116 and 125% with AC as a criterion. RBVs were significantly greater for milk and fermented milk than for the pure vitamin.