Study On The Preparation Of Tannic Acid And Corn Yellow Protein Complex Peptides And Their Antioxidant Capacity

In recent years,peptides with antioxidant activity have gradually become a hotspot of research.Corn Yellow Powder is a main by-product of corn processing which is rich in protein.However,it shows a low bioavailability,so we do a research about the antioxidant activity of Corn Yellow Protein Peptides to improve this shortcoming.This study used Corn Yellow Protein as material and complexes with Tannic Acid.Alkaline protease was chose to hydrolyze the Tannic Acid-Corn Yellow Protein complex and we got the Tannic Acid-Corn Yellow Protein crude peptides.After fractionation,the Tannic Acid-Corn Yellow Protein peptides have been prepared.After that,we studied for its antioxidant activities including in vitro ones and in vivo ones and then test its structure characterizations.Finally,the Tannic Acid-Corn Yellow Protein peptides with high antioxidant activity were obtained.?1?Firstly,different proportions of Tannic Acid were compound with Corn Yellow Protein.Compared with the Corn Yellow Protein solution,when the rate of Tannic Acid was 0.04%,the soluble protein content of Tannic Acid-Corn Yellow Protein solution was increased by 3.55 times,and the antioxidant activity was increased by 23.73%.Single factor experiments were used to screen the four hydrolysis conditions,and the final hydrolysis process parameters of Tannic Acid-Corn Yellow Protein were determined to be 2%enzyme concentration,100mg/mL concentration,40?,pH 8.0.?2?The DA201-C macroporous adsorption resin was used to fractionate the crude Tannic Acid-Corn Yellow Protein peptides,and the results showed that the crude Tannic Acid-Corn Yellow Protein peptides could reach both the highest static adsorption rate and adsorption capacity under the conditions that 100 mg·mL^-1 of concentration,pH 5.0,180 r·min^-1 of rotating speed static adsorbed for 1 h under room temperature.With 95%ethanol solution as eluent,the desorption degree is the most prominent after 5 h desorption under the same conditions.The 95%ethanol was used for elution under the condition that 100 mg·mL^-1 of enzymolysis concentration and pH 5.0,with different flow rates(60,90,120 mL·h^-1),the optimal enzymolysis solution flow rate was selected as 90 mL·h^-1.?3?The in vitro antioxidant activity measurement results showed that compared with Corn Yellow Protein peptides without Tannic Acid and ungraded Tannic Acid-Corn Yellow Protein crude peptides,the activities of Tannic Acid-Corn Yellow Protein peptides which obtained by fractionation have been significantly improved including DPPH radical scavenging ability,·OH radical scavenging ability,O₂?·radical scavenging ability,reducing power and Fe²⁺chelating ability.Among them,the Tannic Acid-Corn Yellow Protein peptides desorbed for 30 min have great antioxidant capacity.The structural characterization results showed that the addition of proper amount of Tannic Acid can make the structure of Corn Yellow Protein get loose due to the effect of hydrogen bonding.?4?The three components with the highest antioxidant activity in vitro were selected for further research on their antioxidant activity in vivo.The results showed that the SOD,GSH-Px,and T-AOC levels of the Tannic Acid-Corn Yellow Protein peptides for 30 min desorption were higher than those of other Groups,and the MDA level was lower.In addition,hepatocytes were observed with HE staining,and it can be clearly seen that the Tannic Acid-Corn Yellow Protein peptides for 30 min desorption have a significant protective effect on cell morphology.Furthermore,it was verified that the Tannic Acid-Corn Yellow Protein peptides had a better protective effect on ethanol-induced cell damage.