Protein modifications screening of raw and thermally treated meat gastrointestinal digesta

Meat samples were subjected to thermal processing combined with simulated INFOGEST in vitro gastrointestinal (GI) digestion. Protein modifications (PMs) were screened with commercially available PM-specific antibodies. Specific proteins at 20, 37, 50, and 65 kDa react to more than 3 PM-specific antibodies among meat proteins. Lysine methylation and methionine oxidation were the most prominent PMs in WB. Mass spectrometry confirmed bands at approximate to 20 kDa as allergenic proteins: sarcoplasmic calcium-binding protein in oyster, 37 kDa as tropomyosin in shrimp, oyster, and abalone. MS-identified PMs of shellfish allergens were aligned to the IgE binding epitopes. GI digestion-resistant peptides of shellfish proteins were identified as paramyosins in oyster and abalone and SBP in shrimp. Our results point to the high susceptibility of immunodominant epitopes of major shellfish allergens to PMs. In TPM, saturation of oxidative modification increases with thermal processing resulting in higher susceptibility of TPM to gastric digestion.