Practical Limitations of the Dilute Acid Hydrolysis Method for Solubilizing Meat and Bone Meal Protein

A previous study reported conditions that hydrolyze meat and bone meal (MBM) protein in a site-specific manner, transforming insoluble MBM protein into large, soluble protein fragments with good flocculant functionality. It is not clear, however, that this phenomenon can be adapted for industrial-scale processing of MBM at reasonable expense. The present study examines whether the desirable characteristics of the reaction product are retained when hydrolysis is conducted using much higher MBM concentration, MBM with relatively large solid particles, and in the presence of fat and bone. The results showed that bone mineral depressed the conversion rate progressively as the MBM concentration increased. An increase in acid concentration reversed the rate depression, and good conversion rates were achieved for up to 200 g of substrate per liter. Particle size and fat showed no consistent effect on the conversion rate. The reaction was shown to retain its site specificity under all conditions tested. Higher MBM concentration and longer reaction times both favored the production of relatively large peptides (MW >5 kDa). Finally, the protein hydrolysate was shown to retain flocculant properties comparable to those of water-extracted MBM protein. These results indicate that the reaction under consideration could be used to convert MBM protein into a more valuable functional product.