Abstract:Objective This study aims to utilize fresh Tibetan sheep blood as raw material, investigate the enhancing effect of microwave-assisted technology on enzymatic hydrolysis efficiency, and achieve high-value utilization of Tibetan sheep blood.Methods A microwave-assisted trypsin hydrolysis method is employed to enzymatically hydrolyze the proteins. The optimal hydrolysis conditions are established through single-factor experiments and response surface methodology. The resulting hydrolysates are characterized using scanning electron microscopy (SEM) and a fully automated amino acid analyzer.Results The optimal hydrolysis conditions are determined as follows: microwave temperature of 40 ℃, microwave time of 50 min, enzymatic hydrolysis time of 240 min, enzyme-to-substrate ratio of 6 000 U/g, microwave power of 348 W, hydrolysis pH of 10, hydrolysis temperature of 45 ℃, and substrate concentration of 11%. Under these conditions, the highest degree of hydrolysis reaches (26.38±0.75)%. The molecular weight distribution of the resultant small-molecule active peptides shows that fractions with molecular weight >5 000, between 5 000~1 000, and <1 000 account for 0.54%, 10.74%, and 88.72%, respectively.Conclusion The products obtained via microwave-assisted enzymatic hydrolysis exhibit excellent digestibility and absorption properties, and the composition of free amino acids after hydrolysis is more balanced. The microwave-assisted enzymatic hydrolysis method is therefore suitable for optimizing the process optimization of Tibetan sheep blood protein.