Physicochemical characteristics of kombucha based on various concentration of white turmeric (Curcuma zedoaria (Berg.) Roscoe)

Abstract

Currently, kombucha can not only be made from tea but also other substrates such as fruit, vegetables, herbs and spices. This research presented the usage of white turmeric with various concentrations as kombucha substrate to enhance the bioactivity of white turmeric. The study used a Randomized Block Design (RBD) with one factor of white turmeric concentration (0.2%, 0.4%, 0.6%, 0.8%, 1.0%) with three replications each. White turmeric powder was made into drinks with determined concentrations, then fermented into kombucha by SCOBY culture at room temperature for 12 days. Physicochemical characteristics such as acidity content (pH), total sugars, total phenolics, and antioxidant activity was analyzed along with identification of bioactive compounds. The data obtained was analyzed statistically using ANOVA (Analysis of Variance) and Fisher's LSD (Least Significance Different) test at p < 0.05. The best treatment was determined with Zeleny's method. Research showed that kombucha fermentation changed pH, decreased total sugar content, enhanced total phenolic content, and improved antioxidant activity also increased bioactive compounds of white turmeric. The best results were obtained in kombucha with 0.8% (w/v) white turmeric concentration with the characteristics as follows: pH of 3.52 ± 0.02, total sugar content of 3.34% ± 0.08%, total phenol content of 174.20 ± 0.83 mg GAE/ml, and antioxidant activity IC50 of 113.07 ± 1.54 ppm.