Effect Of Physical Modification On The Physicochemical Properties And ACE Inhibitory Activity ACE Inhibitory Activity Of Ovalbumin

Ovalbumin has a wide range of uses in the field of food and medicine.Physical modification of ovalbumin can change the structure of protein molecules,and then improve or enhance the biological activity of ovalbumin.Hypertension is a very harmful disease to human beings,and ACE inhibitory peptide has the function of regulating blood pressure,which is one of the hot spots in the field of bioactive peptide research,and a large number of studies have proved that food derived bioactive peptide has ACE inhibitory activity.In this paper,ovalbumin was used as the research object.The effects of ultrasound and hydrodynamic cavitation on the physical and chemical properties of ovalbumin and the ACE inhibitory activity and molecular weight distribution after enzymatic hydrolysis were studied.The main results are as follows:(1)The particle size,zeta potential,sulfhydryl content on the surface,intrinsic fluorescence,hydrophobicity on the surface and the degree of hydrolysis,ACE inhibitory activity and molecular weight distribution of the protein were studied.The results show that: With the increase of ultrasound power,the average particle size of ovalbumin first decreased and then increased,from 992.45 ± 29.06 nm to 564.90 ±16.83 nm,and then increased to 1032.00 ± 39.60 nm;the absolute value of zeta potential increased,from 5.03 ± 0.67 MV to 8.38 ± 0.74 MV;the maximum absorption peak of endogenous fluorescence(λ max)shifted blue at 1 nm;the content of sulfhydryl group on the surface decreased,from 1.74 ± 0.23 μ mol / g decreased to0.66 ± 0.10 μ mol / g,surface hydrophobicity increased from 265.93 ± 0.71 to 275.63± 2.63,hydrolysis degree did not change significantly,ACE inhibitory activity increased first and then decreased,and when ultrasonic power was 200 W,ACE inhibitory activity reached 76.64 ± 1.10%,which is 26.64% higher than that of the untreated protein sample solution.The proportion of molecular weight distribution in the phase of molecular weight < 264 Da is reduced,and when the ultrasonic power is200 W,the proportion of molecular weight in the phase of < 264 Da is reduced from71.19% to 19.92%.(2)The particle size,zeta potential,sulfhydryl content on the surface,intrinsic fluorescence,hydrophobicity on the surface,hydrolysis degree,ACE inhibitory activity and molecular weight distribution of ovalbumin were studied.The results show that: The average particle size of ovalbumin increased from 739.95 ± 25.67 nm to 939.70 ± 11.17 nm after being treated by cavitation device A.There was no significant change after being treated by cavitation device B.after being treated by cavitation device C and cavitation device D,the average particle size of ovalbumin increased to 1129.50 ± 95.46 nm,and the absolute value of zeta potential decreased from 8.34 ± 0.74 nm after being treated by cavitation device a MV decreased to 5.82± 0.21 MV,and the change was not significant after treatment by cavitation device B,but increased after treatment by cavitation device C and cavitation device D,and reached 19.35 ± 0.64 MV after treatment by cavitation device D;the maximum absorption peak of endogenous fluorescence(λ max)shifted 1 nm red;the content of sulfhydryl group on the surface decreased,and decreased from 1.13 ± 0.21 μ mol / g to 0.23 ± 0.05 μ mol / g;the surface hydrophobicity decreased significantly from294.49 ± 23.60 to 202.88 ± 8.17 after being treated by cavitation device a,207.81 ±4.54 after being treated by cavitation device B,205.41 ± 19.88 after being treated by cavitation device C,205.72 ± 20.60 after being treated by cavitation device D;the degree of hydrolysis increased significantly from 22.13 ± 1.25% to 31.57 after being treated by cavitation device a ± 0.42%,no significant change after being treated by cavitating device B,increased to 31.57 ± 1.25% after being treated by cavitating device C,decreased to 16.82 ± 1.25% after being treated by cavitating device D,and increased to 73.22 ± from 56.35 ± 1.22% after being treated by cavitating device a5.24%,which was 16.87% higher than that of the untreated protein sample solution.After treatment with cavitation device B,cavitation device C and cavitation device D,the change effect was not obvious;the proportion of molecular weight distribution in molecular weight 4012～944 Da stage increased,and that in < 264 Da stage decreased.