Efficient Pretreatment of Waste Protein Recovery from Bovine Bones and Its Underlying Mechanisms

To efficiently utilize bone by-products at the industrial level and alleviate the shortage of protein resources, it is important to improve enzymolytic efficiency by developing economical, effective, and eco-friendly pretreatment methods, and to explore the main factor influencing the efficiency of protein extraction and recovery. A comparative analysis was made on the effect of the pretreatments of lipase, high temperature and pressure, and the combination of both. All pretreatments significantly improved the enzymolytic efficiency, while the lipase pretreatment showed the best overall performance. The degree of hydrolysis after three pretreatments was 12.58%, 9.82%, and 11.79%, respectively. Mechanism analysis indicated that the main factor influencing enzymolytic efficiency was lipid content based on the analysis of the physicochemical properties of bones. The enzymolytic efficiency could reach the maximum at 14.15% by decreasing the lipid content to an optimal level of about 5% and changing the surface elemental content of C, N, and O. These results suggest that the pretreatment that efficiently reduced lipid content was an economical and efficient strategy for improving enzymolytic efficiency of bones.