Microbiological profiles, physiochemical properties and volatile compounds of goat milk kefir fermented by reconstituted kefir grains

Kefir is a health-promoting fermented dairy products, consisting in a variety of bacterial and fungal species. The physical and chemical properties and the correlation between the microbiota and volatile compounds of goat milk kefir fermented by reconstituted kefir grains were investigated. Cluster analysis showed that a strong symbiotic homeostasis system existed in goat milk kefir, indicating that the composition of microorganism in reconstituted kefir grains was still restricted by the original one. Compared with other kefir samples, goat milk kefir 80DE20CN (ratios of kefir grains CN/DE = 80/20) showed significant improvement in physiochemical properties and Fruity flavor. Positive correlations among Lactobacillus helveticus and ethyl acetate, amyl acetate and ethanol, Kazachstania unispora and octyl formate, 1-heptanol and hexanoic acid were obtained by Partial least squares regression analysis (PLSR) model. The results showed that changes in microbial succession patterns may be useful to optimize the physiochemistry and flavor of goat milk kefir or related products.

Automated summary

This study investigated the physical and chemical properties of goat milk kefir fermented by reconstituted kefir grains and the correlation between microbiota and volatile compounds. Cluster analysis showed the presence of a strong symbiotic homeostasis system in goat milk kefir, indicating the influence of the original microbiota on reconstituted kefir grains. Goat milk kefir 80DE20CN (ratios of kefir grains CN/DE = 80/20) exhibited significant improvement in physiochemical properties and fruity flavor compared to other kefir samples. The Partial least squares regression analysis (PLSR) model revealed positive correlations between Lactobacillus helveticus and ethyl acetate, amyl acetate and ethanol, Kazachstania unispora and octyl formate, 1-heptanol and hexanoic acid. These findings suggest that changes in microbial succession patterns can optimize the physiochemistry and flavor of goat milk kefir or related products.