蔗糖和果糖对罗非鱼皮明胶流变性质的影响

Effect of sucrose and fructose on the rheological properties of gelatin derived from tilapia skin

以罗非鱼皮明胶为原料,探讨了添加不同浓度(5.0%、10.0%、15.0%,w/w)的蔗糖和果糖对明胶溶液(1.5%、2.0%、4.0%、6.67%,w/w)p H、黏度、凝胶点和熔化点的影响。实验结果表明:蔗糖和果糖基本不改变明胶溶液的p H;随着明胶浓度的增加,其黏度值分别为1.7、2.2、5.0、13.3 m Pa·s,二者之间呈二项式增大趋势(R^2=0.9994),其凝胶点(T_G)和熔化点(T_M)分别为11.7、14.6、18.8、21.2℃和26.0、26.7、27.8、28.9℃,呈对数增大趋势(R^2=0.9949、1);加入糖后,明胶体系的黏度随明胶浓度的增加呈二项式增大趋势(R^2=0.9993~0.9997),其凝胶点和熔化点也随之增大,相同浓度的蔗糖对凝胶点和熔化点的影响比果糖强;添加糖前后明胶熔化点或凝胶点绝对温度的倒数与明胶浓度的对数呈线性关系(R^2=0.9772~0.9886),符合Eldridge-Ferry模型,可根据该模型求得明胶凝胶过程或熔化过程焓中的值。

The influence of sucrose or fructose（5.0%, 10.0%, 15.0% w/w）on pH,viscosity, gelling point and melting point of fish gelatin（ 1.5% ,2.0% ,4.0% ,6.67% ,w/w）was investigated in this paper.The results showed that the pH of gelatin solutions did not change with the addition of sucrose and fructose.The viscosity of gelatin（ 1.5% -6.67% w/w） were 1.7,2.2,5.0, 13.3 mPa. s respectively, which were increased binomially （R2 = 0.9994）with the gelatin concentration went up.The gelling points （TG） were 11.7,14.6,18.8,21.2℃ and the melting points （ TM ） were 26.0, 26.7,27.8,28.9 % with the increase of gelatin concentration, both TG and Tu were increased logarithmically（ R2= 0.9949 and 1 , respectively） .After the addition of sucrose or fructose,the viscosity of solutions were also increased binomially（R2 =0.9993-0.9997）.The concentration effect of sucrose on TG and Tu of gelatin was stronger than fructose.A nearly linear relation（ F2 = 0.9772-0.9886）was found between the logarithm of the gelatin concentration and the reciprocal absolute temperature of melting or gelling,which was in line with Eldridge-Ferry model.