Enzymatic hydrolysis of minced chicken carcasses for protein hydrolysate production

Animal and poultry processing generates significant volumes of by-products that can be further processed for other uses. In this study, we treated minced chicken carcasses with proteases to produce protein hydrolysates that can be used as nutritional and/or flavor-enhancing ingredients. Five different microbial proteases were investigated for their abilities to hydrolyse the minced chicken carcass: Flavourzyme, Protamex, PB01, PB02, and PB03, with PB02 demonstrating the highest degree of hydrolysis (DH) of the minced chicken carcass (43.95%) after 4 h of hydrolysis. The essential hydrolytic parameters were optimized using response surface methodology in conjunction with Box-Behnken design. The optimal conditions were found to be: enzyme/substrate ratio of 3:100 (w/w), temperature of 51.20°C, pH of 6.62 ± 0.05, and substrate/water ratio of 1:1 (w/v) for 4-h hydrolysis, which resulted in a maximum DH of 45.44%. The protein recovery was 50.45 ± 2.05%, and the protein hydrolysate was high in free amino acids (7,757.31 mg/100 mL), of which essential and taste-active amino acids accounted for 41.74% and 92.64%, respectively. The hydrolysate was comprised mainly of low molecular weight peptides (1-5 kDa, 0.5-1 kDa, and <0.5 kDa), which were potential taste substances and flavor precursors. The resulting hydrolysate might be employed as a nutritive product, an ingredient for flavoring generation or a component of fermentation media.