Physiochemical profile and antioxidant activity of red tea kombucha

Kombucha, a tangy beverage traditionally derived from black and green tea fermentation with a symbiotic culture of acetic acid bacteria and yeasts (SCOBY), has garnered substantial scientific interest. This study focuses on the fermentation of Red Tea Kombucha, investigating the chemical compositions and antioxidants as a function of the fermentation period. The main bioactive compounds, including acetic acid, ethanol, glycerol, and various organic acids, were quantified using advanced analytical techniques such as high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Antioxidant activity was assessed with DPPH radical scavenging over a 14-day fermentation period. Results indicated an inverse correlation between pH and fermentation period, while acetic acid and ethanol concentrations increased proportionally. LC-MS analysis identified a significant fold-change in organic acids such as gluconic acid, citric acid, D-quinic acid, gallic acid, and glutaric acid, correlating with enhanced antioxidant activity. These findings reveal profound shifts in the metabolite profile of Red Tea Kombucha during fermentation and underscore its potential as a bioactive beverage with notable antioxidant properties. This research contributes to a deeper understanding of the biochemical transformations occurring in red tea fermentation and highlights the health-promoting potential of kombucha.