| Angiotensin-Ⅰconverting enzyme(ACE) can prompt Angiotensin-Ⅰwith no catalytic activity into Angiotensin-Ⅱ with vasoconstrictor activity, Angiotensin-Ⅱlead blood pressure to rise. Synthetic drugs like captopril, enalaprilat, lisinopril and other inhibitory drugs were commonly used in the rennin-angiotensin-aldosterone system(RAAS). These drugs have side-effect even though they are good and quick effectiveness, these drugs can let the concentration of drugs in blood increase rapidly which will lead to side effect like angio-edema. Angitensin-Ⅰconverting enzyme inhibitory peptides extracting from natural food have no effect on normal blood pressure and have no side-effect, so many researchers are interested in the extracting of ACE inhibitory peptides from food.The study extracted ACE inhibitory peptides from byproducts of Crucian carp, extracted gelatin from fish scales, corn starch and sweet potato starch as the raw material to made porous starch through enzymolysis. Using ACE inhibitory peptides absorbed in corn porous starch as the core material and gelatin as the wall material to prepare microcapsule through spray drying. Details as follows:1. In this study, byproducts of crucian were used as the raw materials to prepare angiotensin converting enzyme(ACE) inhibitory products on the basis of the inhibitory rate of hydrolysate. Pepsin was identified as the optimal enzyme from alkaline protease, flavor protease, neutral protease, trypsin, papain, and pepsin. On the basis of single factor experiment, the optimal hydrolysis conditions of byproduct of crucian were obtained through RSM, the optimal enzymatic hydrolysate conditions were liquid-material ratio of 1:4.4(g/ml),hydrolysis concentration of [E]/[S]=521u/g, hydrolysis time of 5.3h.Under the optimal conditions, the ACE inhibitory rate of enzymatic hydrolysate reached up to 75.79%.2. Enzymatic hydrolysis fish scales to prepared gelatin, decalcification with hydrochloric acid was followed by proteolytic pretreatment, and then extracted gelatin with hot water.(1) In the process of decalcification with hydrochloric acid, the study investigated the effect of solid-liquid ratio, decalcifying time and the concentration of hydrochloric acid on calcium ion solubility and hydroxyproline solubility, the optimum condition of decalcification was: the solid-liquid ratio is 1:15, the decalcifying time is 3 hours, the concentration of hydrochloric acid is 5%. Large amount of calcium ion dissolved and small amount of hydroxyproline dissolved relatively under this condition.(2) In the process of enzymatic, papain was the best enzyme by examining the effect ofpretreated with neutral protease, flavor protease and papain on scals, On the basis of single factor experiment, the optimal hydrolysis conditions by orthogonal test was as follows: enzyme concentration was [E]/[S]=300u/g, hydrolysis time was 3h, hydrolysis temperature was 45℃, under this conditions, the yield of gelatin is 19.89%, and the viscosity is 6.22mPa·s.3. Study on hydrolysis with glucoamylase and α- amylase of corn starch and sweet potato starch to prepared porous starch. With the water absorption and oil absorption rate of the porous starch as the main reference index, the effect of starch concentration, enzyme proportion, enzyme concentration, initial pH, hydrolysis temperature and hydrolysis time on water/oil absorption of porous starch were tested. The optimal hydrolysis conditions by orthogonal test was as follows: corn porous starch: glucoamylase and α- amylase ratio 4:1, hydrolysis temperature 55℃, initial pH 6.0, hydrolysis time 16 h, enzyme concentration 1.0%, starch concentration 55%; sweet potato porous starch: glucoamylase and α- amylase ratio 3:1, hydrolysis temperature 50℃, initial pH 6.0, hydrolysis time 16 h, enzyme concentration 1.0%, starch concentration 50%.4. ACE inhibitory peptides was absorbed in corn porous starch as the core material and gelatin as the wall material to prepare microcapsule through spray drying, the embeddling rate of microcapsule is 41.25%. |
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