Preparation And Isolation Of Bioactive Peptides From Mackerel Skin

With the continuous improvement of people's living standards,the demand for marine aquatic products is also increasing.In the aquatic process to produce a large number of marine aquatic waste,the current waste is only a simple treatment or when the use of pig feed,which not only the waste of resources,but also cause pollution to the environment.Since 1946,people began to explore how to improve the added value of the waste[1],in recent years,many scholars use the waste to prepare bioactive peptides.Huian food Co.Ltd.is a use of mackerel fish production enterprises,every year in the mackerel processing process to produce a lot of fish and fish and other scraps to be exploited.In this paper,the bioactive peptides were prepared by the method of magnetic immobilized enzyme method and membrane separation method,with the aim of improving the added value of aquatic waste.The specific research contents are as follows:1.Antioxidant peptides were prepared by enzymatic hydrolysis of mackerel fish using three free enzymes(neutral protease,alkaline protease and papain).The results showed that the preparation of neutral protease And the optimum conditions for the preparation of antioxidant peptides were as follows: solid-liquid ratio 1:32 g/ml,enzyme ratio 570 U/g,enzymolysis time 4 h,temperature 52?,pH 6,the hydroxyl radical scavenging rate under this condition was 99.78±0.11%.2.The antibacterial rate was used as the index,and the antioxidant peptide was prepared by enzymatic hydrolysis of the mackerel fish with the neutral protease.The optimum process was to obtain the antimicrobial peptide by the method of response surface method.The ratio of solid to liquid was 2:30 g/ml,the ratio of the enzyme was 6200 U/g,the enzymolysis time was 3 h,the temperature was 53?,the pH was6.50,and the antibacterial rate was 63.45±0.28%.3.The optimum conditions for the preparation of magnetic immobilized enzyme were as follows: the amount of particles was 15 mg,the amount of enzyme was 0.60 mg,the reaction time was 1.50 h,and the pH was 6 h,and the optimum conditions were obtained according to the 2-Level Factorial principle.,The rotation speed was125 r / min and the temperature was 25?.Under this condition,the recovery rate of enzyme activity was 60.56±0.25% and the enzyme activity was 1556.14±6.67 U / g.The bioactive peptides were prepared by magnetic immobilized enzyme,and the retention rate of the magnetic immobilized enzyme was about 50%.4.Three groups of different molecular weight ranges were obtained by microfiltration,ultrafiltration and nanofiltration.The components of MAOI(MW:<500 Da),MAOII(MW:500~3000 Da),MAOIII Points(MW:>3000 Da).The highest scavenging rate of hydroxyl radical was MAOI(96.20±1.31%),followed by MAOII(76.21±0.84%)and finally MAOIII(59.68±0.20%).The MAOI fractions were further purified by RP-HPLC to obtain five components.5.Stability of the MAOI component The experimental results show that the temperature and freeze-thaw times decrease the MAOI component activity,but still maintain good oxidation resistance.Prolonged the number of days to put the antioxidant peptide activity increased slightly,indicating that the mackerel fish skin antioxidant peptide has good stability.