Influence of processing on tannin, flavonoid, polyphenol content, and antioxidant activity of Ivy gourd (Coccinia grandis (L.) Voigt) leaf tea

This study investigates factors affecting tea production from the leaves of Ivy gourd (Coccinia grandis (L.) Voigt) using a natural fermentation method. To evaluate the tea quality, key parameters such as tannin, flavonoid, polyphenol content, and antioxidant activity were monitored throughout the research. The study examined different factors, including leaf moisture loss prior to fermentation, the fermentation temperature and duration, the roasting temperature, and the final product moisture content. The results indicated that drying the leaves to 80% moisture content facilitated the natural fermentation process at 40°C for 5 h. Roasting the tea at 100°C to a final moisture of 8% maintained a stable content of tannin, flavonoid, polyphenol, and oxidation capacity.