Skim powder milk (Nestlé, Araçatuba, Brazil) was reconstituted to
13% (w/w) in distilled water. Reconstituted milk was thermally treated
at 90 °C for 10 min in awater bath and distributed in 500-mL sterile bottles
inside a laminar flow chamber, and then stored at 4 °C for 24 h before
use. On the day of fermentation, the milk bottles were warmed to
42 °C and the cultures were added (0.4%) according to the treatment.
In addition, 40-mL aliquots of the inoculated milk were aseptically distributed
in 50-mL sterile flasks. One flask was prepared for each sampling
time and it was used for all analyses. The pH value, organic acids
and lactose contents were determined in the incubated milk before fermentation,
at pH values of 6.0, 5.5, 5.0 and 4.6 (end of fermentation).