Enhancing stability of reverse micelle-structured Antarctic krill oil via dehydration, demetallization,...

Antarctic krill oil (AKO) is susceptible to oxidation, browning, and flavor degradation during storage. This study evaluated a combined pretreatment strategy (dehydration, demetallization, and deoxygenation) together with antioxidants of varying polarities to enhance AKO stability. The pretreatment alone effectively reduced pro-oxidants, and adding antioxidants further suppressed quality loss. Among the antioxidants tested, hydrophilic ascorbic acid (VC) provided the strongest antioxidative protection for the pretreated AKO, effectively preserving ω-3 polyunsaturated fatty acids (EPA and DHA), maintaining color, and reducing the development of off-flavors. The superiority of VC stems from its multifunctional properties and strategic localization within AKO's reverse micelle structure. As a hydrophilic antioxidant, VC partitions into the aqueous core and the oil-water interface, which is the primary site of oxidation, thereby enabling efficient radical neutralization. This study clarifies the role of antioxidant polarity in structured lipid systems and supports the combined use of pretreatment and VC to improve AKO stability.