Kombucha and its dehydrated and freeze-dried derivatives: physicochemical and microbiological characterization and in vivo toxicity evaluatio

Abstract

Kombucha is a biofilm composed of a symbiotic culture of bacteria and yeast, known as SCOBY (Symbiotic Culture of Bacteria and Yeast). The SCOBY undergoes deterioration processes and loss of nutritional, bioactive and sensory attributes, which negatively impacts its shelf life. These losses can be avoided by drying methods, which help to extend shelf life and preserve the action compounds of its constituents. The objective of this study was to subject and evaluate Kombucha SCOBY to drying techniques by heat dehydration and freeze-drying. Analyses included pH, total soluble solids, total titratable acidity, turbidity, total phenolic compound content, antioxidant activity, microbiological assessment, and toxicity in vivo testing. All analyses were statistically evaluated at a 5% probability level, using SAS software. Both Kombucha beverages and dry products exhibited considerable amounts of phenolic compounds and antioxidant activity. Microorganism counts ranged from 104 to 108 CFU.ml-1 for developed beverages and products. In In vivo tests with Caenorhabditis elegans, no increase in mortality was observed, and worms fed with the fermented products showed enhanced growth. Thus, this study concludes that producing dehydrated and freeze-dried forms of Kombucha-based products is a promising and advantageous field of research for human health.