Optimization of Ultrasound-assisted Enzymatic Preparation of Boneless Chicken Feet Collagen Peptide by Response Surface Methodology

Ultrasound-assisted enzyme extraction method was used to extract collagen peptide of boneless chicken feet. Alcalase was selected to hydrolyze collagen from five commercial enzymes (papain, alkaline protease, complex protease, pepsin and trypsin) and the yield of collagen peptide was used as an indicator. On that basis, the single-factor experiments were carried out with material-liquid ratio, ultrasonic power, ultrasonic time and enzyme extraction time. Then, with collagen peptide yield as the response value, three factors that significantly affected enzymatic hydrolysis were selected for response surface analysis to conduct three-factor three-level experiments. The results showed that the influence of various factors on the extraction rate was as follows: material-liquid ratio>enzyme extraction time>ultrasonic power. The optimal extraction process was the material-liquid ratio of 1:26 (g/mL), ultrasonic power of 250 W and the extraction time of 4 h, and the final collagen peptide yield was 49.24%±0.98%. The solubility of the collagen peptide from boneless chicken feet obtained by process optimization was above 90%. Therefore, Ultrasound-assisted enzyme extraction method can be used in processing industrial production to expand the application market of chicken by-product collagen.