Kombucha: caracterizao da microbiota e desenvolvimento de novos produtos alimentares para uso em restaurao


Kombucha is a refreshing, sweet, and acidic fermented beverage usually prepared with sugared black tea to which a "tea fungus" is added. This "tea fungus" is composed of a bacterial cellulosic pellicle containing a symbiotic consortia of acetic bacteria and yeasts. The growing popularity of this fermented beverage is owed to its reported beneficial effects on human health, although these claims haven't been proved scientifically. Nevertheless, a good number of studies have already demonstrated the potential of this product on cells and model organisms. In the present study, the microbiota of kombucha cultures was evaluated through the isolation, selection, and identification of microorganisms present in the fermented liquid. The yeast species Candida californica, Zygosaccharomyces rouxii and Metschnikowia pulcherrima were identified as well as one bacteria belonging to the Acetobacter genus. The isolated microorganisms were used along with Gluconobacter oxydans CBISA 4270, Gluconacetobacter hansenii CBISA 4276 and CBISA 4277, and Acetobacter aceti CBISA 4417 (ordered from a culture collection) in an attempt to produce a kombucha similar to the one produced with the original cultures. A sensory evaluation test was performed to assess the acceptability of a kombucha produced with a culture from the Laboratory of Microbial Bioenergetics (LMB) from ISA-UL versus a store-bought kombucha, among a group of 34 untrained testers, comprised of 16 men and 18 women aged between 18 and 76 years. The results showed a strong preference for the LMB kombucha, which was considered sweeter and more balanced, although less rich in aroma compared with the store-bought kombucha, which was considered more acidic. Alternative applications for this popular beverage were explored, and new food products based on kombucha were produced, namely "nata de kombucha" (a modification of a popular Philippine product) and kombucha gels.

Keywords: acetobacter, black tea, cells, gluconacetobacter, ph, saccharomyces, zygosaccharomyces

Country: Portugal

Citation: Faculty of Science and Technology (FCT) FCT Departments FCT: Department of Chemistry FCT: DQ - Master's Dissertations

Date Updated: April 30, 2020

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