The falls of the pH values were faster in the soy beverage
than in milk. This suggests a greater rate of production of
organic acids in the soy beverage than in milk, but the HPLC
data did not show this to be the case. It has been observed that,
for a given titratable acidity level, pH values are lower in soy
blends than in milk (Angeles and Marth, 1971). Therefore, the
higher apparent acidification rates observed in soy blends reflect
the lower buffering ability of soy protein as compared to milk
proteins.