Effects of high hydrostatic pressure (HHP) on protein structure and digestibility of red abalone (Haliotis rufescens) muscle

摘要

The protein secondary structure modifications and digestibility of red abalone muscle subjected to high hydrostatic pressure (HHP) treatments (200, 300, 400, and 500 MPa for 5 min) were evaluated. The protein structure was analysed by Fourier-Transformed Infrared spectroscopy. Protein digestibility was evaluated based on the degree of hydrolysis (DH) and peptide size distributions under in vitro gastrointestinal conditions. The intermolecular beta-sheet structure was disrupted at 200 MPa, compensated by the formation of the intramolecular beta-sheet. At 300 and 400 MPa, the beta-sheet structure can fold on itself from the interactions that stabilize the protein structure. The 310-helix structure was significantly looser at 300 MPa. Structural modifications were accompanied by beta-turn formation at 300, 400, and 500 MPa. In vitro gastrointestinal digestion is improved by HHP independently of pressure level. The results suggest that high pressure improve the DH of red abalone as a consequence of beta-sheet and beta-turn conformations changes.