Effect of kefir grain inoculation rate and incubation temperature on characteristics of kefir from soy milk
Subject Areas : Biotechnology and Applied Microbiology journal
Keywords: Kefir, Kefir Grains, Soy Milk,
Abstract :
Soy kefir is a fermented product that is produced by adding kefir grains to soy milk. The purpose of this study was to evaluate kefir grains inoculation rate and incubation temperature on qualitative characteristics of soy kefir. In this study soy milk was inoculated with 2% and 4% kefir grains and incubated at 22°C and 25°C. Chemical (pH, titratable acidity, content of ash and protein), microbiological (population of lactobacilli and yeasts) and sensory characteristrics (aroma, taste, appearance, texture, acidity and effervescence) of all treatments were analyzed. No significant differences (p>0.05) in the pH, titratable acidity, content of ash and protein were found in the treatments. Lactobacilli and yeasts populations increased at 25°C and 4% inoculation. Sensory evaluation indicated that acidity rate and texture of the treatments were different significantly (p<0.01) but no significant differences in aroma, appearance, taste, and effervescence were found in the treatments. In this study soy kefir produced by adding 4% kefir grain and incubated at 22 °C was considered as the best sample with regard to quality.
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