Study On Extraction And Physical-chemical Properties Of Collagen Type Ⅱ From Sheep Scapula

The scapula of lambs herding on natural grasslands in Inner Mongolia was used as material in this paper. Citric acid and pepsin were combined to extract collagen type Ⅱ.The extraction rate was discussed and identified preliminarily. And solubility, viscosity, gel property, emulsibility and emulsion stability were all researched.The effects that three factors of the amount of enzyme, citric acid concentration, extracting time had on collagen type II of sheep scapula were studied. The results showed that extraction rate increased with the increasing of enzyme addition, enzyme extraction, citric acid concentration and extracting time.The self-made collagen was preliminarily identified by SDS-PAGE and ultraviolet-visible (UV) absorption spectrum.The condition of SDS-PAGE were:5%and8%of separating gel, voltage of100V,gel time:2h; The results of analyzing self-made collagen by UV was that the ultraviolet band:190nm～390nm; the concentration:0.1mol/L. The self-made collagen accorded with features of collagen type Ⅱ.Changes of solubility at the condition of different temperature and pH were analyzed. The results show that the solubility decreased with the increase of pH but increased with the increment of temperature until it reached the maximum89.2%at25℃, then it deceased.The effects that collagen concentration, pH, temperature and CaCl2had on gel property of collagen type Ⅱ from sheep scapula were researched. The experimental results demonstrate that:the gel strength grew as the collagen concentration grew and the trend were becoming evident; the gel strength reached the maximum when pH closed to isoelectric point7.The tendency increased obviously the first six hours after gelling and increased gently after fifteen hours; NaCl and MgSO4made gel strength decreased.The research on effects of different pH and temperature on viscosity shows that:the viscosity increased with the increasing of collagen concentration; the viscosity reached its lowest value when pH was7;the increasing of temperature reduced the viscosity of collagen type II from sheep scapula;the denaturing temperature was39℃which was obtained by determining. The effects that collagen concentration, pH, temperature and the concentration of NaCl had on emulsibility and emulsion stability of collagen type Ⅱ from sheep scapula were researched. The results show that:the emulsibility increased with the increasing of collagen concentration, and increased rapidly at first, then increased gently with increasing of collage concentration and stabilized at last.; self-made collagen had good emulsibility when the solution was acid; the emulsibility reached the lowest value; an adequate addition of NaCl improved the emulsibility, but excess NaCl reduced it; the effects on emulsibility was complicated.