Exploring the effect of Antarctic krill oil composition on its oxidation behavior based on three different lipid fractions

In this study, Schaal oven test and OXITEST were used to analyze and compare the oxidation behavior of three lipid fractions with different compositions from Antarctic krill: LF-1, LF-2 and LF-3, which have decreasing astaxanthin and tocopherols levels but increasing phospholipids (PLs), eicosapentaenoic acid and docosahexaenoic acid contents. Thereby, the effect of lipid composition of Antarctic krill on (AKO) its oxidative behavior was investigated. The results showed that the conventional oxidation indexes, especially peroxide value and thiobarbituric acid-reactive substances, were not accurate to evaluate the oxidation degree of lipid components, and the changes of astaxanthin and tocopherols content also confirmed this conclusion. The changes in the contents of PLs, amino acids and pyrrole indicated that non-enzymatic browning was involved in the oxidation process of AKO. LF-3 showed the highest degree of non-enzymatic browning and the highest final pyrrole yield of 1.607 mmol/g. The results of OXITEST showed that LF-2 showed the strongest oxidative stability with an induction time of 7.77 h, which was related to the protective effect of astaxanthin and tocopherols, the moderate degree of non-enzymatic browning and the possible synergistic antioxidant effect between tocopherols and PLs. This study has guiding significance for us to think about what kind of lipid composition can show strong oxidative stability, and has a positive impact on the development of AKO products with good storage stability. Graphical abstract