Unraveling the biological potential of chicken viscera proteins: a study based on their enzymatic hydrolysis to obtain antioxidant peptides

Abstract The production of chicken meat has been growing over the years, with a proportional increase in waste generation. Since it is a residue rich in protein, hydrolysis through proteases can provide technological and biological improvements in this substrate offering new opportunities for exploration by the industries. Therefore, this work aimed to study the enzymatic hydrolysis of proteins from chicken viscera and to characterize the hydrolysates in terms of their antioxidant properties and molecular weight distribution. Additionally, hydrolysate production was scaled-up from 125 mL flasks with 50 mL of protein solution to 3 L using a 6 L bioreactor. The enzymatic hydrolysis of chicken viscera proteins using a binary mixture of proteases (Alcalase™ 2.4L and Flavourzyme™ 500L) resulted in an increase of up to 245% for ABTS, 353% for DPPH, 69% for FRAP and 145.95% for total reducing capacity (TRC). The antioxidant properties of the protein hydrolysates are preserved during the scale up of enzymatic hydrolysis. Protein fractions smaller than 5 kDa showed the highest ABTS and DPPH radical scavenging activities, while fractions with molecular weights greater than 30 kDa showed the best results for the FRAP method. Enzymatic hydrolysis proved to be an efficient strategy to add value to solid wastes from the poultry industry.