Study On Preparation Of Antihypertensive Peptides From Tilapia Scale And Skin

Antihypertensive peptide is a kind of low molecular protein peptide which has blood pressure lowering effect.Compared to chemical medicine,antihypertensive peptide from food protein has advantages of high safety,strong absorption and digestion,no effect on normal blood pressure and no side effects,which made it become the hotspot in the field of biological active peptide.This paper studied on the preparing process of antihypertensive peptide from fish skin and scale with the method of single factor and orthogonal test.First,respectively optimizate the process of skin-degreasing,skin-bleaching and scale deashing;and next hydrolysis with composite enzymatic,the degree of hydrolysis(DH)and ACE inhibition rate as index;then ultra filtrate ACEIP respectively,compare the ACE inhibition rate of different fraction,determinate the amino acid composition of high inhibition rate of ACE component,and analysis its molecular weight distribution by using the MALDI-TOF-MS method,finally,conduct animal experiment according to the optimal process for the production of fish skin collagen antihypertensive peptide.The experimental results are as follows:The optimal process of fish skin processing antihypertensive peptide:first degrease,NaOH concentration 1%,solid-liquid ratio 1:12,30 min;next bleach,NaClO concentration 15 mL/100g materials,oxidation bleaching 4h,H2C2O2 to substrate quality ratio 1%,reductive bleaching 50min;then enzymolysis,55?,pH7.0,solid to liquid ratio 1:5,enzyme to substrate quality ratio 2.0%,5h.The hydrolysate has DH 34.48%,ACE inhibition rate 76.16%,and yield 83.43%.The ACE inhibition rate of component of molecular mass less than 2000Da is the highest,reaching 81.11%;the component contain mainly Gly and Pro,respectively 22.21%and 11.51%;its molecular mass ranges 600-800Da.The optimal process of fish scale processing antihypertensive peptide:first deash,HCl content 3.5%,solid-liquid ratio 1:12,1.0h,then enzymolysis,55?,pH 8.0,solid to liquid ratio 1:6,enzyme to substrate quality ratio 2.5%,5h.The hydrolysate has DH 37.48%,ACE inhibition rate 76.66%and yield 35.46%.The ACE inhibition rate of molecular mass less than 2000Da component is the highest,reaching 80.15%;the component contain mainly Gly and Pro,respectively 22.04%and 11.40%;its molecular mass ranges 1300-2000Da.Quality and health indicators of scale and skin ACEIP meet collagen hydrolysate standards of QB2732-2005.Acute toxicity test showed antihypertensive ACEIP in this experiment are non-toxic substances.Animal experiment shows that ACEIP in spontaneously has significant antihypertensive effect on SHR,up to 30mmHg,and no significant effect on WKY which has normal blood pressure.