Study On The Decoloration Of Porcine Hemoglobin And Angiotensin-I-converting Enzyme Inhibitory Peptides Derived From Globin With Enzyme

The present study was designed to decolorize porcine hemoglobin hydrolysis with activated carbon and carboxymethyl starch,the decoloration ratio and the loss rate of protein were chosen as indices to optimize the decolorizing condition.The degree of hydrolysis was chosen as an index to optimize the hydrolysis condition of globins with pepsin and papain.Under optimum hydrolysis conditions,through detecting angiotensin-Ⅰ-converting enzyme inhibitory activity at different phases in the globin hydrolysis,the high angiotensin-Ⅰ-converting enzyme inhibitory peptides was separated by Sephadex G-25.It could be determine angiotensin-Ⅰ-converting enzyme inhibitory activity in each ingredient.1.The decoloration of porcine hemoglobin hydrolysis by activated carbon.The effects of the activated carbon quantity,pH,temperatures and time on the decoloration of porcine hemoglobin enzymatic hydrolysis were studied in orthogonal experiments.The result indicates that the quantity of activated carbon 1%,pH4.0,temperature 80℃,time 40minutes were optimal decoloration condition,decoloration ratio of enzyme solution was 87.68%,the loss rate of protein was 37.83%.2.The decoloration of porcine hemoglobin hydrolysis by carboxymethyl starch. According to the single-factor experiment,20minutes for decolorization was determined. Effects of the quantity of carboxymethyl starch,pH and temperature on decoloration of porcine hemoglobin enzymatic hydrolysis were studied in orthogonal experiments.The result indicates that the quantity of carboxymethyl starch 0.2%,pH4.0,temperature 50℃, time 20minutes were optimal color-removing condition,the decolourization ratio of enzymatic hydrolysis was 84.9%,the loss rate of protein was 12.29%.3.Three factors quadric orthogonal rotatable design were used to study on hydrolysis of globins by pepsin,orthogonal experiments design were used to study on hydrolysis of globins by papain.And then the effects of hydrolysis in different phases of each enzymatic hydrolysis mode on angiotensin-Ⅰ-converting enzyme inhibitory activity were measured. The result exhibits that the optimal conditions as following:the amounts of pepsin 0.3%, pH2.6,substrate concentration 0.7%,temperature 37℃,time 4 hours,the highest inhibiting rate on angiotensin-Ⅰ-converting enzyme was 93.2%;the amounts of papain 0.7%,pH5.2, substrate concentration 0.7%,temperature 56℃,time 3 hours,the inhibiting rate on angiotensin-Ⅰ-converting enzyme was 90.49%.4.For separating high angiotensin-Ⅰ-converting enzyme inhibitory peptides derived from globins,the Sephadex G-25 possessing size-exclusion property was designated as chromatography material.The appropriate eluting condition parameters were determined with three different phosphate buffer ion densities,while 0.5mL/min as the eluting rate. The result shows that the globins hydrolysis could be detached four components by Sephadex G-25 with pH8.3 and 0.03mol/L phosphate buffer ion density,and the highest angiotensin-Ⅰ-converting enzyme inhibitory by the fourth ingredient could reach 93.3%.