Exploring in vitro protein digestion of dry fermented sausage under different thermal processing methods: Peptidomics and molecular simulation

This study investigated the effect of various thermal processing methods (steaming, boiling, roasting, and frying) on the protein digestibility of dry fermented sausages. The results showed that thermal processing improves gastric digestibility by inducing protein denaturation, transforming β-turns and α-helices into β-sheets. Among them, the steamed sausages exhibited the best protein digestion characteristics, with the highest combined gastric/intestinal digestibility (89.06%), the highest proportion of small peptides (<1000 Da) in the digestion products (39.29%), and abundant bioactive peptides with antithrombotic and antiamnesic effects. Molecular simulation results indicated that actin conformation at 90 °C is more open with increased flexibility, and its binding free energy with pepsin decreased from -61.32 kJ/mol to -66.75 kJ/mol, revealing the molecular mechanism of enhanced protein digestion from an energetic perspective. This study provides a theoretical basis for enhancing the nutritional quality of fermented meat products through optimized thermal processing.