Effects of thermal processing on protein quality and bioactivity of tilapia: Explored by in vitro and computer simulated digestion

Thermal processing plays a crucial role in tilapia consumption. To investigate the effects of heat treatment on tilapia protein quality and biological activity, this study employed three methods—steaming, microwaving, and baking to process tilapia protein, followed by static INFOGEST In Vitro digestion. Protein quality assessment indicators included degree of hydrolysis, molecular weight distribution, amino acid composition, and scoring. Bioactivity was verified through In Vitro experiments and computer simulations. Results indicate that thermal processing significantly enhances protein digestibility and amino acid availability by moderately altering protein structure and exposing enzymatic cleavage sites. Among the treatments, baked achieved the highest degree of hydrolysis, essential amino acid index, and biological value; while steaming exhibited the highest amino acid release rate and essential amino acid score. Concurrently, thermal processing significantly enhanced tilapia protein bioactivity: Baked markedly increased hypoglycemic activity, with the α-amylase and α-glucosidase inhibitory activities after gastrointestinal enzyme hydrolysis in the baked group reaching 51.48% and 51.74%, respectively, significantly higher than the 42.72% and 41.17% in the fresh group. Steaming substantially elevated antioxidant activity, with ABTS radical scavenging activity reaching 69.00% compared to 57.96% in the fresh group.