Use of different substrate resources in the production of kombucha tea

Kombucha tea is defined as a fermented beverage with lightly sour- sweet flavor. It is obtained by Kombucha fungus which consisting of symbiotic association of various bacteria and yeast. Kombucha tea is unfortunately not much known in our country. Moreover, it is noteworthy that scientific studies related to this subject are rarely mentioned in the literature. This scope of work; The examination of the development of different plant-fruit tea and coffee Kombucha mushrooms and the determination of the differences in development with various sugar sources. In this study; 6 different teas including black tea, green tea, sage tea, pomegranate (hibiscus) tea, blueberries tea, rosehip tea and coffee; glucose, fructose, xylose, lactose, sucrose (70 g/L) were also used as a carbon sources.As a results of research; The pH value of all products decreased during fermentation. Fermentation samples obtained from fruit teas had a higher acidity than herbal teas and coffee. The amount of phenolic substance and antioxidant activity of the Kombucha tea obtained at the end of fermentation revealed the potential to be a product of considerable level. Biomass development was generally determined in the tea samples, most in glucose and sucrose sugar, at the least in fructose sugar. In the case of coffee, the amount of biomass is the highest in lactose sugar whereas the amount of biomass is the least in samples of fructose sugar. While the most active sugar used in black tea is glucose, other all sources is consumed fructose. The amounts of xylose and lactose sugars were found to be the least in all teas. Color change were not observed in samples of pomegranate as a result of fermentation. L, a, b values of blueberry and rosehip Kombucha tea samples were changed by fermentation for using xylose. It has been determined that, L, a, b values of herbal tea were changed by fermentation in glucose, xylose and fructose sugar medium and these changes are statistically significant.In the organic acid profile of the Kombucha tea samples; oxalic acid presence increased in glucose and sucrose sugar while decreased in other carbon sources by fermentation. Tartaric acid values were determined to be increased with fermentation. Generally, malic acid was not detected before fermentation and malic acid formation was observed with fermentation. Lactic acid was not initially present in fruit teas, sage tea and coffee samples but the end of fermentation, lactic acid acid formation occurred. In case of black tea and green tea samples, the amount of lactic acid increased in glucose media and decreased other carbon sources by fermentation. Citric acid was detected all carbon sources after fermentation except for pomegranate tea. Succinic acid was obtained as a result of fermentation in fruit teas and the amount of succinic acid was increased. This organic acid amount decreased in green tea and coffee samples which prepared with glucose. No fumaric acid presence was found in black tea samples. At the end of fermentation, fumaric acid formation was detected in blueberry, rosehip, green tea and coffee samples with fructose. Fumaric acid presence was observed in pomegranate tea with prepared glucose, xylose and fructose and sage tea with prepared presucrose, xylose, lactose and fructose. None of samples showed no presence of ethanol at the end of fermentation. According to the results of sensory analysis, it is determined that the most popular product is pomegranate (hibiskus) Kombucha tea while the least preferred fermented tea is Kombucha tea obtained with sage tea.As a result of this work, the production of Kombucha teas was carried out on different substrates using different fruits, herbal teas and coffee extracts. Thus, different consumption possibilities were established and the chemical compositions of the products obtained were examined.