Open AccessGrowth and activity of probiotic bacteria in fermented milks fortified with polyphenol extract from strawberry by-product
Author(s) -
Milena Dimitrova,
Ivelina Ivanova,
Aleksandar Slavchev,
Galin Ivanov
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1031/1/012100
Subject(s) - streptococcus thermophilus , lactobacillus rhamnosus , food science , lactobacillus , fermentation , lactic acid , lactobacillus delbrueckii subsp. bulgaricus , chemistry , polyphenol , probiotic , lactose , lactobacillaceae , bacteria , biology , biochemistry , antioxidant , genetics
The effect of polyphenol-enriched extract from a strawberry by-product (SPE) on lactic acid production and the viability of Lactobacillus delbrueckii subsp. bulgaricus S19 (Lb. bulgaricus), Lactobacillus rhamnosus YW (Lb. rhamnosus) and Streptococcus thermophilus S13 (Str. thermophilus) in fermented milks during refrigerated storage was investigated. The fermented milks, with SPE (samples S1 and S2) and without the addition of the SPE (samples K1 and K2), were stored at 4±2°C for 15 days. A constant tendency to decrease in the pH values from 4.40±0.06 to 4.05±0.11 and an increase in the lactic acid concentration from 8.33±0.10 g/L to 11.12±0.41 g/L, respectively, were observed. The residual lactose content of the control and test samples at the end of the refrigerated storage was in the range of 31.44±0.39 g/L. The addition of polyphenol-enriched extracts did not significantly affect (P>0.05) the viability of Lactobacillus spp. and Str. thermophilus during the refrigerated storage.