Antioxidant activity and functional properties of protein hydrolysate from chicken (Gallus gallus domesticus L.)bone by-products

This study was conducted to evaluate the physiochemical, antioxidant activity, and functional properties and assess the cooking and eating properties of chicken meat patties, and determine the effects of selected isolated protein hydrolysate on properties of chicken meat patties. The freeze-dried hydrolysate had high protein content of approximately 85% and a moisture content of 11.3%. For color properties of protein hydrolysates (PHS) a* value of protein hydrolysates with bromelain (PHSB) showed the same trend as protein hydrolysates with papain (PHSP). b* value of control sample was more yellow than the others. Determination of protein molecular weight by SDS-PAGE method, revealed that peptides had an average molecular weight of less than 29 kDa. Emulsifying ability index (EAI) and emulsion stability index (ESI) exhibited values lower than the control. Reducing power of PHSP showed higher activity than PHSB, and 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity also increased when enzyme concentration increased, PHSP presented DPPH with higher activity than PHSB, PHSP at 0.5% w/w was chosen to be used in chicken meat patties. Moisture content and a sub w decreased when PHS was increased. The color of chicken meat patties showed that b* increased when the patties were stored longer. The panelist accept the sample stored in refrigerated temperature in a range of moderately acceptable, and sample P2 (chicken meat patties with 2% w/w PHS) are most preferred patties. Shear force of chicken meat patties with PHSP was higher than control. The Thiobarbituric acid reactive substance (TBARS) values of treatment sample increased from 0.41 to 0.91 mg/kg of malonaldehyde (MDA), during refrigerated storage for 7 days, P2 and P3 showed lower than control and P 1, respectively. Antioxidant activity (AOAt) increased with increasing level of PHSP, and the treatment showed higher than control. The use of 0.5% papain enzyme for chicken bone meat hydrolysis and application of 2% w/w PHS in chicken meat patties were recommended for optimum levels of antioxidant and functional properties.