RESUMEN
BACKGROUND: Kombucha beverage is considered as a dietary supplement and drinking it strengthens the body's immune system which prevents diseases. OBJECTIVE: The purpose of this study was to determine the amount of glucuronic acid and antibacterial activity of Kombucha black tea drink during its production at different storage temperature. METHODS: The extent of glucuronic acid at temperatures of 20°C and 30°C was explored by the use of the HPLC system for 21 days. To analyse the antibacterial property, the influence of Kombucha black tea supernatant on the growth of Salmonella typhimurium, Staphylococcus aureus, and Lactobacillus rhamnosus bacteria was examined via the two procedures of the disc and agar well diffusion. RESULTS: The production of glucuronic acid underwent a variation at 20°C from 17.0 mg/L on day 1 to roughly 27.2 mg/L on day 21, and the difference was significant. Furthermore, the quantity of this acid at 30°C increased from 42.2 mg/L on day 1 to 48.0 mg/L on day 21. The amount of glucuronic acid produced at 30°C was significantly greater than that at 20°C (p<0.05). This study indicated that the Kombucha black tea has antibacterial activity against Salmonella typhimurium and Staphylococcus aureus, but not against Lactobacillus rhamnosus. However, there are no statistical differences in antibacterial activity of Kombucha between incubation at 20oC and 30oC (P>0.05). CONCLUSION: This study offers a perspective on glucuronic acid production (especially in 30°C rather than 20°C) and antibacterial activity of Kombucha black tea beverage.