Salivary α-amylase initiates the digestion of dietary polysaccharides in the oral cavity, yet its indirect influence on gastric protein hydrolysis is not fully understood. This study evaluated the effect of salivary amylase–digested polysaccharides on protein hydrolysis under simulated gastric conditions. Food-grade starch was hydrolyzed by salivary α-amylase and mixed with bovine serum albumin (BSA) in the presence of pepsin. The degree of hydrolysis was measured at different time points using the OPA spectrophotometric assay and verified by SDS-PAGE. The results showed that amylase-digested polysaccharides significantly enhanced protein hydrolysis during the early stages of digestion (15–30 minutes), and SDS-PAGE confirmed faster fragmentation of protein fractions in the experimental samples. These findings suggest that salivary amylase–hydrolyzed polysaccharides promote early gastric proteolysis by altering the physicochemical properties of the gastric environment and improving enzyme–substrate interactions, which may have implications for nutrition and clinical practice.

Salivary amylase, Polysaccharides, Protein hydrolysis, Pepsin digestion, Gastric physiology, Macronutrient interactions, In-vitro digestion

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