<![CDATA[Kombucha is a fermented beverage produced through the symbiotic activity of acetic acid bacteria and yeasts within a SCOBY (Symbiotic Culture of Bacteria and Yeast). This study aimed to evaluate the chemical characteristics and antioxidant activity of kombucha produced from various rhizomes, namely turmeric (Curcuma longa), white turmeric (Curcuma zedoaria), aromatic ginger (Kaempferia galanga), ginger (Zingiber officinale), and Javanese turmeric (Curcuma xanthorrhiza), with black tea kombucha used as a control. Fermentation was conducted for 12 days using black tea kombucha as the starter culture. The analyzed parameters included pH, total acidity, total sugar, total phenolic content, and antioxidant activity determined using the DPPH radical scavenging method. Data were analyzed descriptively, and the best treatment was selected using a Multi-Criteria Decision-Making (MCDM) approach with the Simple Additive Weighting (SAW) technique. The results demonstrated that rhizome-based kombucha fermentation decreased in pH and total sugar content, accompanied by increases in total acidity, total phenolic content, and antioxidant activity. Among the tested treatments, white turmeric kombucha exhibited the best overall performance, with a pH of 3.75, total sugar content of 3.11%, total phenolic content of 117.8 µg GAE/mL, and antioxidant activity of 72.97%. Nevertheless, the antioxidant activity of white turmeric kombucha remained lower than that of black tea kombucha as the control. These findings indicate that rhizomes, particularly white turmeric, have potential as alternative substrates for functional kombucha production, although further optimization is required to enhance their antioxidant capacity]]>
