Monitoring of B-complex vitamins in yogurt during fermentation

Abstract

SummaryEight commercially available yogurt starter cultures were examined for their ability to synthesize water-soluble vitamins. In order to yield comparable assaying conditions, 12·5% reconstituted whole milk was used for yogurt production throughout the experiments. When applying the traditional method of yogurt manufacture (short-time incubating at 42 °C/3–4 h) with all cultures the following vitamins were enriched during fermentation by more than 20%: thiamin (two cultures), pyridoxine (four cultures), folic acid (one culture), and biotin (two cultures). Two starter cultures were selected and used to compare vitamin profiles during the two different methods of fermentation. In contrast to short-time incubation, long-time yogurt production (30 °C/14–16 h) led to a lesser production of folic acid, but to increased concentrations of thiamin and of nicotinic acid.