Studies On Preparation, Anti-oxidant Capacity Of Polypeptides From Sika Deer Fetus And Its Microcapsule Product Development

In our country, the sika deer fetus is a rare traditional tonic,which was honoured as one of “Three treasures of gynaecology”( deer fetus,black bone chicken,donkey hide gelatin)in ancient times. It have much efficacy including the warming uterus for dispelling cold,regulating menstruation, enriching blood,maintaining beauty and keeping young,nourishing ovary,treatment of infertility and so on. The folk had been spreading a rumor:“The emperor hunted deers in order to drink blood of deers,the queen searched deers in order to eat deer fetus”,which indicates deer fetus has a long history on function of body building and keeping beauty. With the development of deer farming in our country, deer fetus is no longer difficult to obtain,satisfying the demands of people in a large scale. Due to the shackles of traditional ideas, in domestic existing deer products are mainly simple processing product of raw materials.Most products are produced by traditional processing technology, such as deer fetus cream, without combination of modern food process technology.Level of products are low.The availability of biotechnology is not high.,neither the additional value of products. Therefore, the exploitation and utilization of deer fetus products have vast potential for future development.From the standpoint of the development and utilization of Sika deer fetus,this paper studies the process conditions of preparing deer fetus polypeptide microcapsule. First I confirm the extraction process of protein. Then the deer fetus protein is digested to product deer fetus polypeptide.According to the polypeptides is easily affected by the external environment and internal environment of digestion to inactivate and leading to low bioavailability, spray drying method is choosed to produce the microcapsule. Chitosan is selected to be wall material, encapsulated the sika deer fetus polypeptides into microcapsules, The process conditions are determined. The main research contents and conclusions are as follows:1. Comparing the difference of Salt method and alkali method to extract deer fetus protein.According to the single factor test and response surface analysis results,extracting deer fetus protein is determined by using alkali method. The optimum process is as: extraction time 3.4h, extraction temperature 45℃, lye concentration 1.6%,solid-liquid ratio 1:35. Determined the isoelectric point(p I) of deer fetus protein is 4.0. The best salting concentration 50%.2. Deer fetus protein is hydrolyzed by enzymatic hydrolysis to preparate deer fetus polypeptides.Different proteases enzymolysis effect were investigated, determined using papain to enzymatic hydrolysis of deer fetus protein. According to the single factor test and orthogonal test analysis results,the process conditions for preparing deer fetus polypeptides by papain are as follows: hydrolysis time 2h, solid content 10%, enzyme amount 7000u/g.3. Researching the anti-oxidant capacity of sika deer fetus polypeptides. Through the determination of DPPH scavenging ability,superoxide anion radical scavenging ability(-2O·), hydroxyl radicals scavenging ability(·OH) reduction ability, the results show that the deer fetus polypeptides have certain antioxidant capacity.4. Adopting spray drying method to produce the deer fetus microcapsule. Chitosan is selected to be the wall material. The process parameters for microencapsulation was determined by the method of Plackett-Burman(PB) combined with central composite design(CCD): supply air rate27 m 3 /h, solid content1.8%, core/wall ratio1:4.5, feed flowrate0.43L/h, inlet air temperature153℃. The test shows that the process conditions are reproducible and feasible.5. The physicochemical properties,sensory properties, microstructure, slow-released properties of deer fetus polypeptides had been studied.The result shows that the microcapsule is in powder form, uniform color, straw yellow, no impurity, no bad smell, slightly deer fetus smell and powder is exquisite.Using the scanning electron microscope(SEM) to watch the microstructure of the microcapsules,the SEM pictures shows that they are round,independent from each other and no adhesion.the surface is flat and no crackle.So it can protect the core material. By in vitro simulated gastrointestinal environment, the release of the microcapsules were studied. Results show that the microcapsules can protect the core material and have good slow-release and enteric properties.