Preparation of soymilk yoghurt with different associations of lactic acid bacteria

Abstract

Soy-based yoghurts were prepared using a mixed starter of L. acidophilus + S. thermophilus, L. acidophilus + L. bulgaricus or S. thermophilus + L. bulgaricus in soymilk with and without addition of carbohydrates for different incubation periods. Increase of acid production was verified when a mixed starter of L. acidophilus + L. bulgaricus or S. thermophilus + L. bulgaricus was used in soymilk supplemented with carbohydrate; however, different results were obtained with L. acidophilus + S. thermophilus. Among different treatments studied, soymilk yoghurts with pH near or equal to 4.0 were selected and submitted to chemical analysis and sensory evaluation. Only three soy-based yoghurts prepared with soymilks and supplemented with sucrose, lactose or sucrose + lactose, incubated for 20, 24 or 20 hours, respectively, and with mixed starter of L. acidophilus + S. thermophilus gave better flavor. The same samples were submitted to preference test which showed that the soy-based youghurt enriched with sucrose was the best.