Fabrication and characterization of anchovy protein hydrolysates-polyphenol conjugates with stabilizing effects on fish oil emulsion

[Display omitted] •The protein and polyphenol contents of conjugates were influenced by the number of –OH group.•Anchovy protein hydrolysate (APH)-Catechin/Gallic acids showed better antioxidant capacities.•APH-Catechin at ratio of 5:1 yielded the most bioactive peptides during conjugation.•The physical stability of fish oil emulsions was enhanced by APH-Tannic Acid 5:1 conjugate.•The oxidative stability was elevated by APH-Gallic acid 10:1 conjugate. Conjugation between peptides and polyphenols could improve their bioactive and functional properties. The improvement effects of anchovy protein hydrolysates (APH) -polyphenol (catechin (CA), gallic acid (GA), tannic acid (TA)) conjugates were investigated. The content of protein and polyphenols and ratio of polyphenols/peptides in conjugates increased as the number of OH group increased with TA > CA > GA. Results showed that APH-CA and APH-GA exhibited the highest ORAC and ABTS+ scavenging capacity, respectively. Mass spectrometry analysis suggested the highest number of bioactive peptides were identified in APH-CA 5:1 (APH/polyphenols). The physical stability of fish oil emulsions during storage was significantly enhanced by TA 5:1 conjugate followed by CA 5:1 conjugate. The oxidative stability was remarkably elevated by APH-GA 10:1. This was due to the antioxidant capacity and the peptides adsorbed at the interfacial. This study demonstrated that APH-polyphenol conjugates could bring the possibility of utilizing peptides-polyphenols in the nutraceutical and functional food ingredient fields.