An in vitro digestion study of tannins and antioxidant activity affected by drying “Rojo Brillante” persimmon
Cristina M. González, Empar Llorca, Amparo Quiles, Isabel Hernando, Gemma Moraga
Abstract
This study focuses on the evaluation of soluble and insoluble tannins and their antioxidant activity in fresh and dehydrated “Rojo Brillante” persimmon after in vitro digestion. Persimmon and its derived products contain a high amount of tannins with high antioxidant activity. An inversely proportional relationship between soluble and insoluble tannins was observed marked by the deastringency and hot air-drying treatments. Furthermore, the antioxidant activity after the hydrolysis of insoluble tannins was greater compared to soluble tannins. After small intestine in vitro digestion, the recovery of soluble tannins was higher in samples dehydrated at 40 and 60 °C, and insoluble tannins remained intact. Therefore, soluble tannins could be absorbed in the small intestine and insoluble tannins could reach the colon microbiota, both indicating potential health-promoting properties. Therefore, hot air drying and freeze-drying are alternative treatments to develop dehydrated persimmon snacks or powdery ingredients to improve nutritional properties of new foods.