3.1. The growth and acidification performance of
the strain
The pH values and microbial population during soy whey fermentation
with L. plantarum are shown in Fig. 1. A decline of
pH value during fermentation was observed. The pH decline
rate was more pronounced at the first 4 h of L. plantarum fermentation
and then slowed down at the later period of
fermentation, which mainly due to the accumulation of lactic
acid. This decline in pH during fermentation was known to act
as a preservative factor against bacteria associated with spoilage
and against non-desirable and pathogenic microorganisms
which were not able to proliferate under these conditions