In Fig. 1(c), the effect of the kind of support on ethanol concentration
during whey fermentation is illustrated. The highest ethanol
concentration was observed by kefir cells immobilized on
MSR compared with that produced by kefir FC and immobilized
on GP, DCM or BSG. Specifically, ethanol concentration was significantly
higher (P < 0.05) in the case of MSR biocatalyst compared to
that from fermentations conducted by kefir FC or by the rest biocatalysts.
But in Fig. 1(a) is shown that the residual sugar concentration
was significantly higher (P < 0.05), while the sugar
conversion was significantly lower (P < 0.05) in the whey fermentation
by MSR biocatalyst compared with fermentation by FC and
GP, DCM or BSG biocatalysts. It would be explained, assuming that
lactic acid bacteria, contained in kefir microflora, could also metabolise,
except lactose, the whey amino acids via non-transaminating
reactions and endogenous transamination, as has been reported
elsewhere (Liu et al., 2003).