Original scientific paper
https://doi.org/10.15567/mljekarstvo.2017.0405
Analysis of metabolic activity of lactic acid bacteria and yeast in model kefirs made from goat’s milk and mixtures of goat’s milk with mare’s milk based on changes in electrical conductivity and impedance
Dorota Cais-Sokolińska
; Poznań University of Life Sciences, Faculty of Food Science and Nutrition, Department of Dairy Technology, 60-624 Poznań, Poland
Jacek Wójtowski
; Poznań University of Life Sciences, Faculty of Veterinary Medicine and Animal Science, Department of Animal Breeding and Product Quality Assessment, 62-002 Suchy Las, Poland
Jan Pikul
; Poznań University of Life Sciences, Faculty of Food Science and Nutrition, Department of Dairy Technology, 60-624 Poznań, Poland
Małgorzata Lasik-Kurdyś
; Poznań University of Life Sciences, Faculty of Food Science and Nutrition, Department of Fermentation and Biosynthesis, 60-624 Poznań, Poland
Abstract
The aim of this study was to analyse the metabolic activity of lactic acid bacteria and yeast based of changes in electrical conductivity and electrical impedance during fermentation of goat milk and mixtures of goat’s milk and mare’s milk (1:1, 1:2). As a result of fermentation, conductivity increased 1.4-fold. The conductivity of kefir prepared from goat and mare milk mixed at a ratio of 1:2 (6.210 Ω-3∙cm-1) was lower than that of the 1:1 mixture or of goat milk alone (7.242 Ω-3∙cm-1). A significant dependence of electrical conductivity and pH (0.970 ≤ r ≤ 0.993) was recorded during fermentation. The addition of mare milk to goat milk significantly slowed down the growth of LAB (Δλ = 0.8 h) and yeasts during kefir production.
Keywords
conductivity; electrical impedance; goat’s milk; mare’s milk
Hrčak ID:
186937
URI
Publication date:
29.9.2017.
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