Optimizing steaming core temperature to enhance tilapia protein digestibility in an elderly model: structural and...

This study investigated the protein digestion characteristics of tilapia fillets steamed to different core temperatures (60, 70, 80, and 90 °C) under simulated elderly model, and further elucidated the underlying mechanisms through texture and protein physicochemical attributes. Increasing core temperature markedly softened the fillet texture but enhanced protein aggregation. In the elderly model, gastric digestibility increased continuously and reached its maximum at 90 °C, whereas intestinal and total digestibility peaked at 70 °C and decreased significantly at higher temperatures. Although heating to 90 °C further softened the texture, it induced severe protein aggregation that limited enzyme accessibility, thereby impairing intestinal and overall digestion. Correlation analysis revealed that texture predominantly influenced gastric protein digestion, while the degree of protein denaturation was the decisive factor for overall digestibility. Overall, this study elucidates how temperature-dependent structural changes in tilapia proteins influence digestive outcomes in the elderly and offers valuable insights for optimizing protein-based dietary formulations for them.