STUDY OF THE VOLATILE COMPONENTS OF KOMBUCHA DURING STORAGE UNDER REFRIGERATED CONDITIONS

Kombucha is a fermented drink made from sugared tea that is transformed by the activity of a symbiotic colony of bacteria and yeast (SCOBY). This aim of this study was to investigate the changes in the volatile profile of drinks made by two different methods (traditional and alternative) during the storage period under refrigerated conditions. Gas chromatography-mass spectrometry (GC-MS) with solid phase microextraction (HS-SPME) was used to analyse the volatiles of the samples from the two different production methods at different storage times from 0 to 12 weeks. A total of 65 volatile compounds were identified in the samples prepared by the alternative method, while 59 volatile compounds were found in the samples prepared by the traditional method. The main categories of compounds found included acids, alcohols, and esters, followed by terpenes, aromatic hydrocarbons, phenols, and other substances. Statistically significant changes in volatiles were observed in each method during storage, as determined by one-way ANOVA and the Tukey-Kramer test for honest significant differences. Differences in both method and method*time were observed using a two-way test ANOVA. From a global perspective, there were significant differences in substance concentrations during storage at +4°C, characterised by an increase in concentration and ex novo formation of other volatile compounds. Principal component analysis (PCA) was able to distinguish the samples according to the production method (PC1) and the storage period (PC2). This study may provide an important basis for future investigations of the changes in the volatile profile during storage under refrigerated conditions and serve as a starting point for further studies aimed at exploring new and different methods of producing this beverage.