Study On Extraction And Modification By Succinylation Of Pigskin's Collagen

Collagen has been widely applied in the field of medieal treatlnent,health care and beauty fields because of its unique amino acid composition and structure. China is one of the largest pig production in the world. Pigskin is rich in collagen,it has important practical significance to develop pigskin resources and process of the beneficial pig waste for recycling. This subject aims to use pigskin as raw materials to increase the extraction rate of collagen by microwave treatment,and then use succinic anhydride to modify the molecular of collagen and improve their functional properties, to expand its applications.This paper selected the pig skin of Rongchang as raw materials. This paper studies the compositions of pigskin; degreasing agent selection; effects of microwave treatment on extraction yield of collagen:extracted collagen identification; modified succinylated collagen; determination of the nature and acylated collagen. The main results are summarized as follows:(1) Tested obtained:water content was 39.92%, crude fat content was 33.74%, hydroxyproline content was 2.13%, crude protein was 26.46%, collagen accounts for 80% of crude protein in the pigskin. After analyzing and comparing the different effects of degreasing degreasing agent, chloroform: ethanol (2:1;V:V)>5%Na2CO>3>1% lipase> ether:petroleum ether (1:1; V:V)>petroleum ether>ether.(2) This paper studies the different factors on the extraction rate of collagen.And seting extraction rate as target, respectively, using the temperature of the microwave processing, microwave processing time, the ratio and extraction time four orthogonal factors to optimize the extraction rate. The results showed that the order was the solid-liquid ratio>extraction time>microwave time>Microwave temperature. Optimal level was the microwave time 2min, microwave temperature 25℃, solid-liquid ratio of 1:30, the extraction time 35h.(3) Comparing microwave treatment of paraffin sections by microwave treatment,we found collagen more clearly, some collagen fibers shorter and thicker and collagen fibers are dispersed in pig skin. So it can show that the microwave has a strong collagen fiber dispersion. After microwave treatment pigskin can get a higher extraction rate of yield.(4) The maximum UV absorption wavelength of extraction of collagen was at 235 nm, it is full compliance with the characteristics of collagen. The study was approved extraction of collagen has a complete triple helix structure by infrared spectroscopy. Electrophoretic analysis of collagen molecular showed weight of the three peptide chains are larger than 97 kDa,it is similar withIcollagen. Denaturation temperature of collagen show it has a good spatial structure and biological activity.(5) Collagen response with succinic anhydride to modify functional properties, IR spectrum showed the test was successful. Experiments showed that the addition of succinic anhydride, reaction time, reaction temperature, pH value were important factors in the reaction. Response surface showed that the reaction time>anhydride> temperature> pH. It is optimized to obtain the optimal level of collagen protein acylation conditions, the amount of succinic anhydride,15.15%, pH value of 9.10, temperature 39℃, time 3.01h, then the theoretical value predicted collagen 71.446%.(6) Experiments contrast the nature of collagen and acylation of collagen showed several conclusions. Isoelectric point of acylation collagen was in the shift to the acidic environment,There was the greater the degree of acylation, but the isoelectric point of was smaller. After acylation solubility of collagen was significantly enhanced, Generaly the higher acylation correspond with the higher solubility. Emulsifying activity has been strengthened and expanded the scope of application,and the emulsion stability has been improved over the previous. The maximum value of gel strength offset close to the lower pH value.Before the temperature reaches 60℃, the gel strength of acylated collagen increases with increasing temperature. Gel strength did not significantly change when the temperature between 60℃and 80℃. Temperature exceeds 80℃, gel strength of acylated collagen began to decline, and with the greater the degree of acylation, the faster the decline in gel strength.