Development and Evaluation of Piper sarmentosum-Based Kombucha: Fermentation, Bioactivity, and Sensory Acceptance

Piper sarmentosum, renowned for its bioactive properties, was explored as a material for kombucha production. This study investigated P. sarmentosum-based kombucha (PSK), focusing on its phytochemical content, antioxidant and antibacterial activities, anti-amylase effects, and sensory attributes during a 21-day fermentation period. An increase was found in the total flavonoid content (TFC) of PSK from 6.02 mg QE/L at the start to 34.07 mg QE/L after 21 days of fermentation. Similarly, the total phenolic content (TPC) increased from 108.2 mg GAE/L to 266.2 mg GAE/L during the same period. Antioxidant activity of PSK, assessed through DPPH and ABTS assays, reached 0.33 µmol TE/mL and 0.51 µmol TE/mL, respectively, by day 21. While PSK did not show significant antibacterial activity against Escherichia coli and Salmonella typhi, it exhibited increased inhibition against Vibrio cholerae (inhibition zone dimeter of 18.3 mm) and Staphylococcus aureus (inhibition zone dimeter of 23.2 mm) by day 14, with a decrease by day 21. Additionally, α-amylase inhibition increased from 10.7% on day 0 to 15.4% on day 21. Sensory evaluations indicated that a 14-day fermentation period optimally balanced sweetness, sourness, and astringency of kombucha. Our study results indicate that P. sarmentosum is a promising substrate for preparing kombucha.