Potential of snake fruit (Salacca zalacca (Gaerth.) Voss) for the development of a beverage through fermentation with the Kombucha consortium

Sugared snake fruit juices were fermented for 14 days with the Kombucha consortium containing yeasts and acetic acid bacteria. Five Indonesian cultivars (Salak Doyong, Salak Madu, Salak Pondoh, Salak Segaran and Salak Suwaru) of the fruit were studied. The physicochemical and sensory properties of the fermented products revealed the snake fruit Kombucha from the Salak Suwaru cultivar as the most acceptable with color indices L* and b* respectively 30.5 and 13.2; total sugar, 7.54%; total soluble solids, 11.3%; total acidity, 1.65%; pH, 3.15; and sensory scores (out of 5) of 3.90 for color, 3.70 for taste and 3.80 for aroma. The fermentation enhanced antioxidant activity of the snake fruit Kombucha, as assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and consistent with increases in phenolics, tannins and flavonoids. Acetic acid was the major organic acid of the fermented product that showed an enhanced antibacterial activity by inhibiting Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Snake fruits can be used to develop functional food beverages and foods through the Kombucha fermentation.