Biological activity of optimized phenolic extracts of quince (Cydonia oblonga Miller) parts before and after simulated in vitro gastrointestinal digestion

In this study, the phenolic extracts of Es,me quince parts (pulp, peel, seed, juice, and leaf) were obtained under optimized extraction conditions. Then, the total phenolic content (TPC), the quantities of main phenolic compounds, antioxidant, and antimicrobial activity and the change in bioactivity properties (TPC, antioxidant capacity, and antimicrobial activity on the same sixteen microorganisms) after in vitro digestion of each quince part were evaluated. The order of TPC and antioxidant activity was determined as leaf > peel > juice > pulp > seed. After in vitro gastrointestinal digestion, a decrease was observed for the TPC (average 5-fold reduction) and antioxidant activity (more than 2.5-fold reduction) in all quince parts except quince seed than their extract forms. The quince leaf extract exhibited the highest antibacterial activity. Overall, this study exhibited that the quince leaf was considered a promising, cheap, and natural source for nutritional or pharmaceutical applications with biological activity properties.

Automated summary

This study obtained phenolic extracts from different parts of quince under optimized extraction conditions and evaluated their properties. The results showed that quince leaf had the highest total phenolic content and antioxidant activity. After in vitro digestion, the total phenolic content and antioxidant activity of all quince parts decreased. Quince leaf extract exhibited the strongest antibacterial activity.