Abstract:

The research of the impact of barley and oat malt extracts as prebiotic complex on the viability and biochemical activity of Lactobacillus spp. and Bifidobacterium spp. was presented in the paper. The intensive growth of bacteria Lactobacillus spp. and Bifidobacterium spp. 1 hour after fermenting the milk-malt mix with BME and OME in the ratio 95:5 based on the starter "Bifivit" compared with based on the starter "Symbilakt" was proved. The number of CFU of bacteria Lactobacillus spp. and Bifidobacterium spp. in 1sm3 of this fermented beverage was 1,59±0,04*108 at the end of shelf life, which corresponded to the recommended number of CFU of probiotic lactic acid cultures in foods according to FAO/WHO. The optimum mass fraction of solids for administering malt extracts to a dairy base was 14 %, which allowed to reach the greatest numbers of CFU of bacteria Lactobacillus spp. and Bifidobacterium spp. The concentrations of lactic acid in fermented beverages with 95 % BME and 5 % OME based on the starter "Bifivit" were twice higher than based on the starter "Symbilakt", which was shown by accelerated acid coagulation and reduced duration of the biotechnological processing of the milk-malt mix. The combination of bacteria Lactobacillus spp. and Bifidobacterium spp. of two starters provided lactic acid extraction in probiotic fermented beverages with BME and OME at a level that does not exceed the maximum allowed, and prevented the accumulation of significant concentrations of D(-)- lactic acid. The best aromatic composition of secondary fermentation metabolites was in the fermented beverage with 95 % BME and 5 % OME based on the starter "Bifivit", which corresponded to low concentrations of acetaldehyde (27.00 mg/cm3), n-propane (11.84 mg/cm3), isobutane (29.30 mg/cm3), acetaldehyde (27.00 mg/cm3) and high concentrations of 2-methyl-1-butanol (77.37 mg/cm3) and 3-methyl-1-butanol (211.11 mg/cm3), and the concentrations of methyl acetate (10.61 mg/cm3) and ethyl acetate (85.11 mg/cm3) were optimal for forming harmonious aroma of the fermented beverage. Author Biographies Наталія Василівна Чепель, National University of Food Technology 68, str. Volodimirskaya, Kyiv, Ukraine, 03680 Candidate of engineering, Associate ProfessorDepartment of technology of milk and dairy product

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