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

Abstract

This study sought to assess the efficacy and mechanism of vacuum, ultrasonic, and combined ultrasonic-vacuum treatments (under N2 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.