Biocatalytic conversion of poultry processing leftovers: Optimization of hydrolytic conditions and peptide hydrolysate characterization.

Peptide hydrolysate (PH) was produced by deep controllable bioconversion of poultry processing leftovers (broiler necks), by means of a multienzyme composition, containing four commercially available enzyme preparations (Alcalase, Neutrase, Flavourzyme, Protamex). The design of multienzyme composition (MEC) was applied to yield a hydrolysate with adjusted properties, including minimized antigenicity and bitterness. The protein recovery was optimized using Box-Behnken response surface design. The individual and interactive effects of hydrolysis conditions (time, hydromodule and MEC dosage) were studied. The experimental data were analyzed by ANOVA method and a well-predictive, second order polynomial model was developed using multiple regression analysis. Optimal hydrolysis conditions were found to be: hydrolysis time 3 h, hydromodule 2.25 l/kg and dosage of MEC 0.25%. The corresponding predicted value for protein recovery was 75.34%, 2 times higher compared to traditional long-term heating hydrolysis. The PH obtained is a low allergenic product with high antioxidant capacity.