Delivering polyphenols for healthy ageing

There is a growing demand for delivery of antioxidants through functional foods with the concomitant challenge of protecting their bioactivity during food processing and subsequent passage through the gastrointestinal tract. This study focuses on the retention of antioxidant activity of polyphenolic antioxidants after encapsulation/spray-drying. The polyphenolic compounds present in grape-seed extract (GSE), apple polyphenol extract (APE) and olive-leaf extract (OLE) were analysed by chromatographic methods. Catechin, epicatechin and gallic acid were identified in GSE and APE. Oleorupein is the major compound found in OLE. Total polyphenol content was found to be the highest in APE followed by GSE and OLE. These extracts were encapsulated using protein-lipid emulsions and subsequently spray-dried. Optical microscopy and particle size distribution analysis indicated the sphericity and uniform size distribution pattern of the dry particles. Radical scavenging activity studies demonstrated significant retention of antioxidant activity after the encapsulation and spray-drying process.