Abstract:[Objective]This study aimed to screen composite enzyme formulations, optimize the enzymatic hydrolysis of chicken protein, and investigate the digestive characteristics of the resulting hydrolysates.[Method]Chicken slurry was hydrolyzed using two composite enzyme formulations: composite enzyme formulation 1, consisting of alkaline protease at a mass fraction of 2% and papain at a mass fraction of 2%; and composite enzyme formulation 2, consisting of papain at a mass fraction of 2% and flavourzyme at a mass fraction of 2%. Enzymatic hydrolysis was performed at 55 ℃ for 1.5 h. The degree of hydrolysis, peptide mass fraction, free amino acid composition, and volatile flavour compounds were determined. The hydrolysis efficiency, digestive characteristics, and physiological effects of the hydrolysates were comprehensively evaluated using in vitro simulated digestion and a mouse model.[Result]The degree of hydrolysis achieved with both composite enzyme formulations exceeded 56%, and peptides with a relative molecular mass below 500 accounted for more than 94% of the hydrolysates. The results of in vitro digestion experiments showed that the crude protein digestibility of composite enzyme group 2 was 87.48%, significantly higher than that of composite enzyme group 1 (P<0.05). The proportion of peptides with a relative molecular mass less than 500 in the digestion products of composite enzyme group 1 and composite enzyme group 2 was 92% and 90%, respectively. In the animal experiment, the crude protein apparent digestibility in mice fed the hydrolysate produced using composite enzyme formulation 2 reached 82.64%.[Conclusion]Both composite enzyme formulations effectively promoted chicken protein hydrolysis. Composite enzyme formulation 2 performed better in improving product digestibility, providing a feasible processing approach for the value-added utilization of chicken protein.
