During incubation, for the first 6 h, growth of S. thermophilus
was faster in soy beverage than in milk. This confirms the data in
the literature which show that S. thermophilus is well able to
grow in soy beverages because of its ability to use sucrose
(Angeles and Marth, 1971; Karleskind et al., 1991; Chumchuere
and Robinson, 1999). Cane sugar added to the soy beverage in
this study may also have contributed to this faster growth.
However, growth of S. thermophilus stopped after 6 h during soy
beverage fermentation, which was 2 h earlier than during
fermentation of cows' milk. This may be due to the faster drop in
pH during soy beverage fermentation.