KINETICS OF SACCHAROSE FERMENTATION BY KOMBUCHA

The kinetics of saccharose fermentation by Kombucha is not yet well defined due to lack of knowledge of reaction mechanisms taking place during this process. In this study, the kinetics of saccharose fermentation by Kombucha was analysed using the suggested empirical model. The data were obtained on 1.5 g L-1 of black tea, with 66.47 g L-1 of saccharose and using 10 or 15% (V/V) of Kombucha. The total number of viable cells was as follows: approx-imately 5x10(5) of yeast cells per mL of the inoculum and approximately 2x10(6) of bacteria cells per mL of the inoculum. The samples were analysed after 0, 3, 4, 5, 6, 7 and 10 days. Their pH values and contents of saccharose, glucose, fructose, total acids and ethanol were determined. A saccharose concentration model was defined as a sigmoidal function at 22 and 30 degrees C, and with 10 and 15% (V/V) of inoculum quantity. The determination coefficients of the functions were very high (R-2 > 0.99). Reaction rates were calculated as first derivatives of Boltzmann's functions. No simple correlation between the rate of reaction and independent variables (temperature and inoculum concentration) was found. Analysis of the empirical model indicated that saccharose fermentation by Kombucha occurred according to very complex kinetics.