THE EFFECT OF KOMBUCHA STARTER CULTURE ON THE GELATION PROCESS, MICROSTRUCTURE AND RHEOLOGICAL PROPERTIES DURING MILK FERMENTATION

摘要

This study is concerned with the effect of kombucha starter culture on the rheological properties, texture and microstructure as well as on the protein fractions in different phases of milk fermentation. The results were compared with those obtained for the samples prepared with yoghurt and probiotic starters. Quality parameters in the course of fermentation at 42C were measured at the pH values of 5.4, 5.1, 4.8 and 4.6. The viscosity values measured at pH 5.4 indicate similarity of the gelation processes taking place in the samples involving kombucha and probiotics. The sample produced with kombucha had the highest value of complex modulus, which resulted in better rheological characteristics of the final product. The earlier onset of the gelation process induced significant differences among the samples in the microstructure at pH 5.4. The analysis of the protein profile revealed better stability of alpha and beta casein fractions compared with the other protein fractions in particular phases of milk fermentation.