Digestibility And Enrichment Research Of Half-fin Anchovy Antimicrobial Peptide

Half-fin anchovy?Setipinna taty?,one species of marine fish,was selected as material to prepare half-fin anchovy antimicrobial peptide?HAHp?using the method of pepsin hydrolysis.In this paper,the properties of HAHp were evaluated as the following aspects:?1?Gastric digestion characteristics of HAHp in simulated in vitro model;?2?Intestinal digestion characteristics of HAHp in simulated in vitro model;?3?Modified magnetic Fe₃O₄@SiO₂ nanoparticles enriched with HAHp.The digestion characteristics of HAHp were studied by simulated gastric juice digestion model in vitro.The protein concentration,peptide concentration,total amino acid content,glycated serum content,glucose content and total antioxidant capacity of HAHp were determined under 0-120 minutes digestion.The results showed that peptide concentration and total amino acid content were increased;whilst protein concentration,glycated serum protein?GSP?content and total antioxidant capacity were decreased in addition of glucose or fructose to HAHp in the process of gastric juice digestion.After the end of digestion?digestion time of 120 min?,the peptide concentration,protein concentration,total amino acid content and total antioxidant capacity of the fructose-added HAHp were higher than their corresponding ones in glucose-added HAHp.The digestion characteristics of HAHp were studied by simulated intestinal digestion model in vitro.The protein concentration,peptide concentration,total amino acid content,GSP content,glucose content and total antioxidant capacity of HAHp were determined under0-5 hours digestion.The results showed that the addition of glucose or fructose to HAHp decreased the protein concentration and GSP content during the intestinal digestion.By comparison,the total amino acid content and total antioxidant capacity were increased in the intestinal juice after glucose or fructose addition.After the end of intestinal digestion?5h?,the fructose-added HAHp demonstrated significant increase of total amino acid content,GSP content and total antioxidant capacity as compared with the glucose-added HAHp.The magnetic Fe₃O₄ particles were used as the basic particles,and the magnetic nano Fe3O4 modified by sol gel method was used to enrich the active peptides of HAHp.The results of TEM analysis showed that the modified magnetic nano Fe₃O₄ adsorbed active peptides of HAHp and formed a“corona”on the surface of the particles.After adsorption by modified Fe₃O₄,the antimicrobial activity of HAHp solution to Escherichia coli was significantly reduced.The content of peptide and protein in HAHp decreased from 7.249 mg and 416.221?g before adsorption to 6.297 mg and 346.183?g respectively,while the content of amino acid in the peptide solution increased slightly after adsorption.The results of high-performance liquid chromatography showed that the retention time and peak area of main separation peaks of HAHp were changed after adsorption by modified magnetic Fe₃O₄,which indicated that modified magnetic Fe3O4 could effectively adsorb antimicrobial peptides in HAHp and enrich antimicrobial components.