Kombucha fermentation using commercial kombucha pellicle and culture broth as starter

Abstract

Kombucha is a fermented beverage containing organic acids by yeast and acetic acid bacteria. In this study, microbial community analysis of kombucha produced in Korea was performed, and changes in components during kombucha fermentation were analyzed using commercial kombucha pellicle and culture broth as starter. The major phylum-level strains of commercial kom-1 and kom-2 showed differences in proteobacteria of 35.60% and 78.1%, and Firmicutes of 64.06% and 15.57%, respectively. During fermentation with pellicle (Kom-P) and broth (Kom-F), the level of reducing sugar during fermentation tended to decrease rapidly. The production of acetic acid and D-saccharic acid-1,4-lactone (DSL) in Kom-P and -F tended to increase with increasing fermentation time. In Kom-P, lactic acid and glucuronic acid production increased until 7 days of fermentation and then decreased, whereas in Kom-F, it continued to increase with fermentation time. ABTS radical scavenging activity tended to decrease with increasing fermentation time. However, DPPH radical scavenging activity increased within 7 days of fermentation and then decreased slightly (Kom-P) or remained constant (Kom-F). It has been found that the use of culture broth rather than the use of pellicle as a starter is advantageous to increase the active compound content and DPPH radical scavenging ability.

Keywords:
kombucha; black tea; radical scavenging activity; DSL; glucuronic acid