Antioxidant and antimicrobial potential of peptidic hydrolysates from duck egg proteins

Purpose The purpose of this study is to evaluate the antioxidant and antimicrobial efficacy of duck egg protein hydrolysates produced through enzymatic hydrolysis using different proteolytic enzymes. Design/methodology/approach Duck egg proteins were hydrolyzed for 6 h using four proteolytic enzymes, namely, alcalase, ficin, papain and trypsin at an enzyme-to-substrate ratio of 1:100, with samples collected at 2 h intervals. The resulting hydrolysates were analyzed for pH, degree of hydrolysis (DH), antioxidant activity, namely, 2,2’-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and superoxide anion scavenging activity (SASA) assays and antimicrobial activity. Findings A decrease in pH was observed with increasing hydrolysis time. The DH increased significantly (p < 0.05) up to 6 h with alcalase, papain and trypsin, whereas in ficin it increased significantly (p < 0.05) only up to 4 h, followed by a non-significant rise. Antioxidant activity (ABTS, DPPH, FRAP, SASA) also increased significantly (p < 0.05) with hydrolysis time and DH. Trypsin hydrolysates showed the highest ABTS, DPPH and SASA activities, while papain hydrolysates exhibited the highest FRAP activity. The strongest antimicrobial activity against the tested microorganisms was recorded in trypsin hydrolysates at 6 h. Originality/value This study demonstrates that enzymatic hydrolysis of duck egg proteins can generate bioactive peptides with notable antioxidant and antimicrobial properties, highlighting their promise as natural functional ingredients for incorporation into health-promoting foods and nutraceutical formulations.