Effect of the amorphous complexes of gelatin and quercetin on lutein ester emulsions: Evaluation of stability, interfacial properties and bioaccessibility.

Abstract

Lutein esters are carotenoid fatty acids esters with extensive physiological activities. However, susceptibility to oxidation and degradation significantly limits its application in food products. In this study, a novel delivery system based on gelatin-quercetin complex (GEL-QU) was developed to encapsulate and protect lutein esters in emulsions. X-ray diffraction (XRD), Intrinsic fluorescence spectrum and Fourier transform infrared (FTIR) supported that the GEL-QU is an amorphous complex through hydrogen bonding and hydrophobic interactions. GEL-QU improved interfacial activity and emulsion performance. The GEL-QU-based emulsion retained up to 92.50% lutein esters after 14 days storage. The after in vitro digestion retention of increased from 69.45% for GEL to 96.19% for GEL-0.1QU, while bioaccessibility increased from 57.74% to 88.69% for GEL-0.05QU. This study provides a novel strategy for protecting lutein esters from degradation in emulsion delivery systems and could potentially expand the application of hydrophobic bioactive ingredients in functional food design.