During small-scale fermentations, both L. rhamnosus IMC 501® and L.
paracasei IMC 502® grew on buckwheat flour (BF) and oat bran (OB)
and acidified themMRSmedium, lowering the pH after 24 h of growth.
The pH reduction was more pronounced for both strains with 6% of BF
and OB respectively. SYNBIO® in mMRS with 6% BF gave the highest
pH reduction (data not shown). No pH drop was observed in mMRS
medium without an energy source for all lactobacilli tested. As
shown in Table 1 a significant growth of L. paracasei IMC 502® was
detected on 6% of BF and 2% of OB with respect to the negative control.
Interestingly, the probiotic growth in SYNBIO® samples was significantly
higher on 4 and 6% of both BF and OB with respect to the
control. Table 2 shows the time required to reach pH 4.6 ±0.03 during
fermentation in whole milk. As indicated in this table the milk
with different vegetal substrate concentrations required different
fermentation times to reach pH 4.6 ± 0.03. The fermentation period
decreases by increasing the concentration of buckwheat flour in
whole milk. Regarding L. rhamnosus IMC 501® the greatest effect
was observed with 6% buckwheat flour in whole milk as it reached
the required pH in 11 h which is decreased significantly (P b 0.05)
by 5 h as compared to the control. In the presence of 2% oat bran concentration
the fermentation required the same time as the control
and a greater fermentation time significantly higher (P b 0.05) by
3 h as compared to 2% buckwheat flour. Even for oat bran the fermentation
period decreases by increasing its concentration in milk.