Study On Extraction Of Deer Tail Protein And Preparation Of Peptide

In this paper,the deer tail of sika deer(Cervusnippon)was used as raw material to analyze its basic composition,extract deer tail protein and prepare deer tail polypeptide,optimize the preparation process of deer tail protein and polypeptide,and explore the digestibility and antioxidation of deer tail protein and polypeptide in vitro and the activity of promoting osteoblast proliferation and differentiation.The results are as follows:(1)The basic components of sika deer tail were analyzed,in which the water content,fat content,crude protein content and ash content of deer tail were 29%,27.56%,60.52%and 5.66%,respectively.Adopting ultrasonic-assisted water extraction method,through single factor and response surface experiment,the best extraction process of deer tail protein was obtained as follows: material-liquid ratio 1:5,ultrasonic power 400 W,extraction time1 h,extraction temperature 60 ℃.Under this condition,the protein extraction content was60.43%.The purified deer tail protein was further separated by ammonium sulfate fractionation precipitation and anion chromatography exchange,and the mixture of alkaline protease,neutral protease and papain was used as the tool enzyme.The ratio was 1:2:1.The conditions of enzymatic hydrolysis were preliminarily determined by single factor experiment,and the optimum enzymatic hydrolysis process was further optimized by response surface method.The optimum enzymatic hydrolysis process was as follows:temperature 50 ℃,p H7,enzyme dosage 6000 U and time 5h.Under these conditions,the degree of hydrolysis was 26.47%.The deer tail peptides were fractionated by ultrafiltration membrane method,and three kinds of peptides were obtained: under 3k Da,between 3-5k Da and 5-10 k Da,accounting for 96.81% of the total peptides.Through amino acid detection and analysis,the highest content of glycine is 27.7%,and there are more amino acids such as glycine and proline.(2)The extracted deer tail protein and deer tail polypeptide were used to digest casein,bovine serum albumin,soybean meal and fish meal in vitro.Through the determination of amino acid production and the calculation of in vitro digestibility,it was found that both deer tail protein and deer tail polypeptide had digestibility,and the digestibility of deer tail polypeptide was better than that of deer tail protein.(3)Through the determination of the reducing power of deer tail protein and polypeptide and the scavenging ability of DPPH free radical,both deer tail protein and polypeptide have antioxidant ability,and deer tail polypeptide has stronger antioxidant ability than deer tail protein.After fractionation,the antioxidant capacity of deer tail polypeptide is stronger.(4)By measuring the proliferation of MC3T3-E1 cells and the activity of alkaline phosphatase(Alkalinephosphatase,ALP),it was found that both deer tail protein and deer tail polypeptide could promote the proliferation of osteoblasts,and the effect of small molecular weight deer tail polypeptide was more obvious,and the smaller the molecular weight was,the greater the promoting effect was.Osteoblasts were cultured with isolated small molecular peptides,and all the peptides had a good effect on promoting proliferation and differentiation.