Kinetics of Astaxanthin Degradation in Three Types of Antarctic Krill (Euphausia superba) Oil during Storage

Abstract Three types of Antarctic krill oil (KO), namely, phospholipid‐type krill oil (PKO), whole krill oil (WKO), and triacylglycerol‐rich krill oil (TKO), were stored at three different temperatures (−20, 4, and 25 °C) with or without oxygen to investigate the effects of temperature and oxygen on astaxanthin (AST) degradation during storage. Additionally, the influence of fatty acid composition on AST degradation in the three types of KO was compared. The results revealed that the degradation of AST followed first‐order kinetics, and the temperature dependence of the reaction was well explained by the Arrhenius relationship. A high storage temperature led to faster AST degradation. AST degradation rates under nitrogen were lower than those under an oxygen atmosphere. The higher degradation rate of AST in PKO is ascribed to its higher level of polyunsaturated fatty acids (PUFA) in comparison to WKO and TKO. This is the first time the energy of activation of AST degradation was evaluated to determine how the fatty acid composition of the oil matrix and storage atmosphere affect the reaction kinetics.