Abstract:
In the study, 80% acidic methanol was used to extract the tannin of hand-picked green persimmon by the ultrasonic-assisted method combined with enzymatic hydrolysis. The total phenolic content was determined by Folin-Ciocaileu method, and the tannin content was determined by the vanillin-sulfuric acid method. The effects of different conditions on the tannin content and yield of persimmon fruit were investigated by single factor experiment and an orthogonal experiment. The results show that the optimal extraction conditions are as follows: the addition of cellulase is 0.5 g, the ratio of material to liquid is 1∶15, the concentration of hydrochloric acid is 1%, the extraction time is 90 min, and the extraction temperature is 80 ℃. The total phenolic content, condensed tannin content and yield of the extract are 29.13 mg/g, 22.33 mg/g, and 7.08%, respectively. The orthogonal experiment was used to optimize the extraction process of tannin from hand-picked green persimmon, demonstrating stability, efficiency, and feasibility.