The physicochemical, antioxidant, and antibacterial properties of turmeric extract fermented with kombucha culture Available to Purchase

Kombucha is a healthy beverage, traditionally made by fermenting sugared tea using a consortium of yeast and acetic acid bacteria called Symbiotic Culture of Bacteria and Yeast (SCOBY). This research aimed to utilize turmeric extract as an alternative for the substrate used in the brewing. The chemical properties (pH, titratable acidity, and polyphenol), physical properties (biomass weight and color), and bioactivity (antioxidant and antibacterial properties) of the turmeric kombucha were identified. Turmeric concentration of 2% w/v was used in the fermentation. The variables were inoculum concentration (15% and 30% v/v) and fermentation duration (0, 7, and 14 day(s)). Our results establish the evidence that culture concentration and fermentation duration influenced the physicochemical properties, as well as the bioactivity of turmeric kombucha. As the fermentation was extended, the pH of the sample decreased while the titratable acidity increased. Due to the production of organic acids, the pH at the end of fermentation dropped to 3.33– 3.66 which was lower than the initial pH. The kombucha samples prepared with 15% and 30% of inoculum showed a 1.92-fold and 1.46-fold increase in total acids after 14 days of fermentation. Fermentation also changed the hue of the samples. The kombucha sample moved toward orange hue (68.73–69.68 °) after 14 days of fermentation. Meanwhile, the total polyphenols increased by approximately 1.07 and 1.11-fold than the initial values and their antioxidant activity decreased. The observed turmeric kombucha exhibited antibacterial properties against gram-positive bacteria, such as Staphylococcus aureus and Bacillus subtilis. Kombucha prepared from turmeric extract is a good diversification of turmeric with health benefits due to polyphenol content, antioxidant and antibacterial activities.