Analysis on the elaboration of kombucha

Abstract

Kombucha is a fizzy fermented beverage made from tea, sugar and microorganism (SCOBY, symbiotic culture of bacteria and yeast) that has been known worldwide for centuries, but nowadays is gaining more and more popularity for its health benefits. Consequently, the known fermented beverage that was homemade by a few, is now being produced by breweries at an industrial scale. Despite its increasing popularity, there is still a lack of understanding of the kombucha fermentation process and how it affects the quality and properties of the final product. Furthermore, the industrial production of kombucha is still in its early stages, with little standardization of the production process and quality control measures. This thesis aims to provide a thorough review of the industrial elaboration of kombucha, combining theoretical bases with experimental data obtained in the laboratory. Moreover, the evolution of parameters such as pH (acid content), density, sugar and alcohol content are indicators of the accurate progress of the fermentation and form a tracking system for such process. Experiments performed, following such parameters, confirmed a temperature effect influencing the microorganism’s metabolism and an optimal temperature range of 21-28 ºC, being approximately two times faster at 28 ºC than 21 ºC. In addition, the initial substrate (sucrose) concentration effect was also evaluated and concluded with a minimum, although positive, effect