草鱼盐溶蛋白乳化性的研究

Study on emulsifying properties of salt-soluble proteins from grass carp

在鱼糜制品中,鱼盐溶蛋白(SSP)的乳化特性决定着产品的均匀性和稳定性。首先采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(SDS-PAGE)测定了草鱼SSP主要成分的分子质量。再采用单因素和响应面实验设计研究了pH、离子强度、油水相体积比对草鱼SSP乳化特性的影响。结果表明:SSP中肌球蛋白的重链、两条轻链和肌动蛋白的分子质量分别为200、30、23、40ku。pH和离子强度是影响SSP乳化能力的极显著因素;当pH为7.94,离子强度为0.7,油水相体积比为1:7时,乳化活性指数(EAI)达到最大值,为45.78m2/g。pH是影响乳化稳定性的显著因素;当pH7.3,离子强度0.58,油水相体积比1:5时,SSP的乳化稳定指数(ESI)达到最大值0.812。综合分析乳化特性指标,得出草鱼盐溶蛋白乳化性的最佳条件为:pH7.5,离子强度0.6,油水相体积比为1:7。

Emulsifying properties of fish salt-soluble proteins（SSP）determine the surimi technical qualities such as uniformity and stability.The molecular mass of main compositions of SSP from grass carp were determined using the method of sodium dodecyl sulfate-polyacrylamide gel electrophoresis（SDS-PAGE）.Effects of pH,ironic strength,and the ratio of oil to water volume on emulsifying properties of SSP were studied by single factor and response surface method.The results showed that the molecular masses of myosin heavy chains,two myosin light chains,and actins from SSP were 200,30,23,and 40ku respectively.pH and ironic strength were very significant factors which influenced emulsifying capability of SSP.The emulsifying activity index（EAI）of SSP had the maximum value（45.78m2/g）on the condition of pH 7.94,ironic strength 0.7,the ratio of oil to water volume 1：7.pH was the significant factor which influenced emulsifying stability of SSP.The emulsifying stability index（ESI）of SSP had maximum value on the condition of pH 7.3,ironic strength 0.58,the ratio of oil to water volume 1：5.The optimal condition of emulsifying properties of SSP from grass carp were pH 7.5,ironic strength 0.6,the ratio of oil to water volume 1：7.