Heat treatment caused protein oxidation in abalone muscles, which decreased protein digestibility and transport levels. The addition of AOB inhibited protein oxidation, improving protein digestibility and transport levels.

This study was first time designed to investigate the effect of oxidation on protein digestion and transport properties in boiled sea cucumber body wall (BSCBW) via simulated digestion combine with everted-rat-gut-sac models. Boiling heat treatments led to protein oxidation in SCBW, manifested by increases in free radical intensity, thiobarbituric acid reactive substances, carbonyl groups, disulfide bonds, dityrosine bonds, advanced glycation end products, protein hydrophobicity and aggregation, declines in free sulfhydryl group, and secondary structure transition from α-helix to β-sheet. Boiling for 2 h caused the anti-digestion collagen unfolding, provided the action site for protease, and improved the protein digestion and transport levels. On the contrary, excessive oxidative modification of 4 h-BSCBW resulted in decreased protein digestion and transport levels. From the perspective of texture, digestion and transport properties, boiling for 2 h can obtain sea cucumber products with better edible and digestible properties, which is considered to be a better processing condition.