Ultrasonic-vacuum combined effects on Antarctic krill oil oxidation stability: Potential mechanisms of oxygen reduction and influence on reverse micelle

This study sought to assess the efficacy and mechanism of vacuum, ultrasonic, and combined ultrasonic-vacuum treatments (under N 2 protection) on the oxidative stability of Antarctic krill oil (AKO). Accelerated storage trials demonstrated that all three approaches significantly enhanced oxidation stability through oxygen removal (combined treatment > ultrasonic treatment > vacuum treatment). Comparative analysis demonstrated dehydrated AKO exhibited significantly higher oxidation stability but lower oxygen content and viscosity than hydrated counterparts (0.5 % water addition), and combined treatment's stabilizing effect was more pronounced in dehydrated AKO. Cryogenic scanning electron microscopy images suggested an increase in reverse micelle density upon water addition, and a decrease following combined treatment. This study indicates that water-formed reverse micelles in AKO compromise oxidative stability and attenuate deoxygenation efficiency, likely through increasing viscosity. This study firstly proposes that the combined treatment enhances AKO stability via a dual mechanism of direct oxygen removal and indirect reverse micelle influence.