Proceedings of International Congress on Bioactive Compounds and International Workshop on Bioactive Compounds
Proceedings of 1st International Congress on Bioactive Compounds and 2nd International Workshop on Bioactive Compounds - Vol. 1 - 2018

Chicken blood meal (CBM) is a slaughterhouse by-product mainly used as animal feed. Since CBM is rich in protein including important essential amino acids, it is possibly a potential source of bioactive peptides of interest for the human health. Besides, its valorization is of economic and environmental interest because it comes from the evergrowing chicken meat production, of which Brazil is the 2nd most important producer in the world. In the national scenario, the state of Paraná is the biggest producer, with a third of the Brazilian broiler production in 2017. In this sense, the present study aimed to evaluate the impact of hydrolysis conditions in the antioxidant activity of CBM protein hydrolysates. Hydrolysis by Alcalase® was conducted at constant pH = 8.0 for 90 min, using four combinations of temperature (T) and enzyme-to-substrate w/w ratio (E/S): T = 54 (a) or 62 °C (b) and E/S = 3.5% (A) or 6.5% (B). The reaction was interrupted by enzyme inactivation; neutralization of the pH and heating until boiling temperature (maintained for 10 min) followed by cold-water immersion. The hydrolysates were centrifuged and then concentrated in a rotary evaporator prior to dehydration by freeze drying in order to obtain the hydrolysate powders. The degree of hydrolysis (DH) was determined by the OPA (ortophtaldialdehyde) method. The antioxidant activity of the obtained hydrolysate powders was quantified in terms of DPPH and ABTS scavenging capacities and FRAP. Antioxidant activity values were expressed as mmol of Trolox equivalents (TE) per kg of dried hydrolysate sample (mmol TE/kg) and presented as mean averages ± standard errors of three replicate analyses. The resulting degree of hydrolysis ranged from 18.0% (aA) to 22.8% (bB), positively affected by an increase in both T and E/S (p<0.05). The hydrolysates displayed the same behavior for DPPH and ABTS scavenging capacities, reaching their maximum value (389.05 ± 17.29 and 397.70 ± 9.37 mmol TE/kg, respectively) at the same reaction condition (bA). Meanwhile, this condition resulted in the lowest value for FRAP (24.35 ± 0.33 mmol TE/kg). In addition, the extreme conditions (aA and bB) resulted in the highest FRAP values (29.50 ± 0.25 and 29.51 ± 0.54 mmol TE/kg, respectively), displaying no significant difference between them (p<0.05). This behavior was verified with the estimation of the effects. While DPPH and ABTS scavenging capacities of CBM hydrolysates are positively affected by the hydrolysis reaction temperature, the FRAP is positively affected by the E/S and mainly the interaction between T and E/S (T × E/S). The results confirm that protein hydrolysates from CBM contain antioxidant biopeptides and that the hydrolysis conditions exert significant impact on the antioxidant properties of those hydrolysates. Although the behavior of the antioxidant properties of CBM hydrolysates was determined, the identification of the peptides and their amino acid sequence must be investigated in order to explain the cause of these findings. Nevertheless, CBM is a potential source of antioxidant biopeptides of interest for the food and pharmaceutical industries, which should stimulate new research studies to consolidate their use and applications.