preprints.org > life sciences > biotechnology > doi: 10.20944/preprints202110.0226.v1

Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Version 1 : Received: 14 October 2021 / Approved: 15 October 2021 / Online: 15 October 2021 (14:04:51 CEST)

The aim of this work was to study the production of kefir-like beverage by fed-batch fermentation of red table grape juice at initial pHs of 3.99 (fermentation A) and 5.99 (fermentation B) with kefir grains during four repeated 24-h fed-batch subcultures. However, all kefir-like beverages (KLB) were characterized by low alcoholic grade (≤ 3.6%, v/v) and lactic and acetic acid concentrations. The beverages obtained from fermentation B had lower concentrations of sugars and higher microbial counts than the KLB obtained in fermentation A. In addition, the KLB from fermentation B were the most aromatic and had the highest contents in alcohols, esters, aldehydes and organic acids compared to the non-fermented juice and KLB from fermentation A. These results indicate the possibility of obtaining red table grapes KLB with their own distinctive aromatic characteristics and a high content in probiotic viable cells, contributing to the valorization of this fruit.

kefir grains; red table grapes; kefir-like beverage; fed-batch fermentation; volatile compounds

LIFE SCIENCES, Biotechnology