Total phenolic content, flavonoid content, antioxidant activity and phenolic acid profiles of naturally fermented Carica papaya leaf

In this study, the total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity and phenolic acids of naturally fermented Carica papaya (C. papaya) leaves were evaluated. The total phenolic compounds were extracted by liquid-liquid extraction (LLE) using methanol while free phenolic acids were extracted by acidic hydrolysis followed by LLE using ethyl acetate. The results showed variation of TPC, TFC, antioxidant activity and phenolic acids levels of different samples taken at different sampling points throughout the 100 fermentation period. The highest results, measured in terms of the sample dry mass (dm) relative to standard compounds were as follows: 48.42 ± 0.63 mg GAE/g for TPC at days 75, 14.47 ± 7.94 mg QE/g for TFC at days 33, 2.39 ± 0.55 mg CE/g for Proanthocyanidin at days 100 and finally, 93.82 ± 0.14 % for DPPH radical scavenging at days 60. The phenolic acids decreased with fermentation period. Nevertheless, the presence of these phenolic compounds and their antioxidant activity highlighted the functionality and medicinal values of naturally fermented C. papaya which are comparable to other medicinal plants.