After 12 h of incubation at 30 °C, the pH of Ct-OFB slightly decreased
from 6.45 ± 0.21 to 6.02 ± 0.12. With the aim to get beverages
with final pH of 4.2 ± 0.2, which was considered to be the
optimum for sensory and microbiology characteristics, the fermentation
was stopped after 12 and 8 h of incubation for LP09-OFB and
E-OFB, respectively. The addition of enzymes promoted the fastest
acidification. After fermentation, LP09-OFB and E-OFB had values of
pH of 4.20 ± 0.03 and 4.24 ± 0.08 (Table 3). After fermentation,
the cell number of presumptive LAB was ca. 6.5 × 108 cfu/ml, without
differences between the two beverages. Both for growth and
acidification, the shortest values of λ were found for the beverage
containing the enzyme preparations (Table 4). The value of Vmax
for E-OFB was more than twice compared to the value found for
LP09-OFB. Pasteurization decreased the count of presumptive LAB
to ca. 2.0 × 106 cfu/ml. After thermal treatment, enterobacteria and
yeasts were not found in 10 g of sample. As estimated by plating on
PCA, total bacteria were ca. 5 × 106 cfu/ml.