Study On The Preparation And Antioxidant Activity Of The Hippocampus Bone Polypeptide

Seahorse, as a marine biological medicine material, has a highly medicinal value,which has been recorded as a valuable traditional Chinese medicine (TCM), with thefunctions of physical health, invigorating the kidney, stimulating the circulation of theblood, causing the muscles and joints to relax, anti-inflammatory analgesic, and relievingcough and asthma. So, seahorse is an important biological resource which has potential todevelop a kind of health and care product. As the demand of seahorse product increased, itis necessary to develop technology of the deep processing and utilization of seahorseresource. This experiment used the three-spot seahorse Hippocampus trimaculatus Leachas the raw material, using Supercritical Fluid Extraction (SFE-CO2) technology to study onfat extraction process of seahorse bone, and analyse composition of fatty acids by GC-MS;then, selecting and optimizing the Protease process to the defatted seahorse bone meal byusing Response Surface Experimental Design method; At the last, separating digestedpeptides and verifying their antioxidant capacity.(1)The extraction rate of SFE-CO2technology has been affected by many factors,especially, by the extraction pressure, extraction temperature, extraction time and CO2flow. In this study, a single experiment for these four factors had been done at first. Andbased on these, the orthogonal experimental design had been employed to optimize itsextraction conditions. Then, the composition of fatty acid with the defatted adult seahorsebone meal was analysed by GC-MS. In this study, the extraction pressure was the mainfactor for affecting the oil extraction rate, followed as the extraction time, the extractiontemperature and the CO2flow rate. Through orthogonal experiment method, the optimalextraction conditions were: extraction pressure35Mpa, the extraction temperature58℃,extraction time135min, CO2flow rate15L/h, and under the optimal condition, the lipid extraction rate is1.81%of seahorse defatted bone meal. By GC-MS, the obtained extractcontained fifteen main fatty acids, and the content of unsaturated fatty acids accounted for39.10%of total fatty acid, where EPA and DHA accounted for5.55%and11.00%ofunsaturated fatty acid, respectively.(2)Two proteases had been screened in five to digest the defated seahorse bone mealwith the single factor test. Based on the experiment, the hydrolysis conditions with the twoenzymes were optimized by Response Surface Methodology. The selected2enzymeswere Alkaline protease and Trypsin, and the optimal hydrolysis condition was respectively,Alkaline protease digestion process: temperature54.70℃, pH9, the time6h; Trypsindigestion process: the temperature45℃, pH8.8, time4h. Then, Complex enzymaticprocess to be selected was the Trypsin+alkaline protease, the hydrolysis peptides ofseahorse bone meal was more or less at30kDa.(3)Using dextran G-50chromatography system for separating the enzymatic peptides,the polypeptide separated into three intervals according to the peak time, each wascollected and dried, which would be analysed its function, included the peptides reducedpower, DPPH clearance, clearance of the superoxide anion, hydroxyl radical scavengingrate. The results indicates that the reducing power of the polypeptide, DPPH radicalscavenging, superoxide anion radical scavenging rate, hydroxyl radical (aspect OH)ability showed the same trend. The function of peak2with the polypeptide was the best inall peak, while the peak1is the weakest in the antioxidant capacity.