Optimizing Glucuronic Acid Synthesis in Kombucha Production: A Comprehensive Study on Process Parameters

Sammanfattning

Kombucha, a traditional fermented tea beverage, is gaining popularity for its health benefits due to its bioactive compounds, especially glucuronic acid, known for detoxifying and hepatoprotective properties. Despite its significance, factors influencing glucuronic acid levels are not well understood. This study investigated the impact of initial sugar concentrations (4%, 6%, 8%) and tea types (black, green, oolong) on glucuronic acid synthesis during kombucha fermentation over 20 days. Results showed that pH dropped rapidly in the first three days, then stabilized before declining further until day 20, across all samples. Total soluble solids, measured in Brix values (oBx), decreased quickly initially, indicating microbial consumption, then stabilized. Glucuronic acid concentration, measured using an enzymatic kit, peaked around day 14, with black tea kombucha at higher sugar concentrations achieving up to 0.176 mg/ml, being also significantly higher than green and oolong teas. A subsequent HPLC analysis revealed variations in the metabolite concentrations of some samples, with black tea kombucha showing the highest levels of acetic acid and glucose, while green tea kombucha had the highest ethanol content. Focus groups were also performed, which indicated that different tea compositions and fermentation lengths influenced consumer acceptance, showcasing a wide range of opinions about the product. In summary, initial sugar concentration and tea type significantly affect glucuronic acid levels in kombucha. Optimizing these parameters can enhance the beverage’s health benefits and sensory qualities, contributing to advancements in food science and consumer health.