Lactose-Free Buttermilk in Functional Fermented Dairy Drinks

This research compared the physicochemical, rheological, microbiological, and sensory parameters of lactose and lactose-free buttermilk. They were obtained by whipping cream and converting high-fat cream. The analysis also involved fermented dairy drinks based on lactose and lactose-free buttermilk. They included starter microbiota of different compositions. The samples of buttermilk obtained by converting high-fat cream demonstrated relatively low mass fractions of protein, fat, solids, titrated acidity, and clot viscosity. The composition of the starter microflora affected the clot viscosity and moisture-retaining ability, which depended on the amount of microbial polysaccharide producers in the starter and solids in the buttermilk. The fermented buttermilk contained from 0.6 to 0.7% lactic acid. However, 70–90% lactose in the lactose buttermilk sample was not hydrolyzed and remained in its native form. Lactose-free buttermilk contained monosaccharides, and the content of glucose was by 27 ± 6% less than that of galactose. Bacterial concentrates MSTt, Bifilact-U, and Bifilact-AD provided a high level of starter culture microorganisms (108–109 CFU/cm3). The best sensory profile belonged to the fermented dairy product based on both lactose and lactose-free buttermilk with the content of probiotic microorganisms ranging between (2.7 ± 0.3) × 106 and (4.3 ± 0.6) × 106 CFU/cm3. This optimal sample was obtained with the bacterial concentrate Bifilact-AD, which both contained lactic acid and probiotics. Lactose-free buttermilk demonstrated a high potential for functional fermented dairy drinks fortified with probiotics.