LAUSR

BACKGROUND Heat treatment induced both structural and digestive change of meat protein. However, little have been revealed regarding the associations between structural changes and digested peptides of myofibrillar proteins. This work investigated the effects of heat treatment on the structures and in vitro digestibility of actomyosin, and the peptidomics of the digests were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS Heat treatment resulted in unfolding and aggregation behavior of actomyosin according to the results of surface hydrophobicity and particle size. Formation of disulfide bonds and increase in carbonyl groups that occurred during heat treatment of actomyosin indicated the oxidation of specific residues. , Unfolding behavior could elevat digestibility of actomyosin by exposing for residues, based on the identification of peptides in digests of actomyosin using LC-MS/MS. However, disulfide bond was proved to reduce the action of digestive proteases , since the peptides number (increased from 56 to 86 in sample heated at 70 °C for 30 min) and peptides intensity in digests largely increased after the addition of dithiothreitol (DTT). Heating at higher temperature (100 °C) induced severer aggregation and oxidation, which resulted in lower digestibility of actomyosin than that heated at 70 °C by burying or damaging partial cleavages sites for digestive proteases. CONCLUSIONS This work highlight the huge influence of heat treatment on the multi-scale structures of myofibrillar proteins, which largely changed the peptides composition in protein digests. This article is protected by copyright. All rights reserved.