Phenolic Compound Content, Antioxidant and Radical-Scavenging Properties of Methanolic Extracts from the Seed Coat of Certain Thai Tamarind Cultivars

The study investigated methanolic extracts from the seed coats of five Thai tamarind cultivars for their phenolic content and antioxidant properties. The Priao-yak extract, with the highest tannin content, showed the strongest reducing power, while the Khanti extract, with the highest proanthocyanidin content, exhibited high scavenging ability on DPPH and hydroxyl radicals. The Sithong-bao extract, rich in total phenols, proanthocyanidin, and tannins, demonstrated the strongest overall antioxidative activity. These findings suggested that specific phenolic constituents contributed to the different antioxidant properties observed, indicating potential for developing natural antioxidants from tamarind seed coats into nutraceuticals and food preservatives.