Recent trends in Kombucha: Conventional and alternative fermentation in development of novel beverage

Kombucha is produced by fermenting sweetened tea with symbiotic culture of bacteria and yeast (SCOBY). Kombucha is slightly sweet and acidic tea beverage that is popular all over the world due to its refreshing taste and health-promoting active metabolites formed during the fermentation process. Sucrose-sweetened tea is the traditional substrate for kombucha fermentation. However, due to consumers’ demand as well as availability of resources, various alternative substrates, such as honey, molasses and coffee, have been used in the production of kombucha over time to promote additional health benefits. Aside from that, kombucha fermentation supplementation, such as with herbs, bee pollen, and lactic acid bacteria, have also been used to develop new novel kombucha, to value-add the biological activities and sensory properties. The activity of Komagataeibacter spp. bacteria results in the formation of a polymeric cellulose pellicle during the kombucha fermentation process. The cellulose produced has a wide range of application in a variety of fields. In this review, conventional and alternative fermentation methods were reviewed to better understand the development of kombucha.