罗非鱼肉蛋白的分离及其性质研究

Isolation and characterizing of Tilapia proteins

研究以罗非鱼肉为原料,采用化学方法分离鱼肉蛋白的水溶性、盐溶性和不溶性蛋白3个组分,并对其营养特性、功能特性和分子量分布进行检测和分析。结果表明：罗非鱼肉分离蛋白组分占总蛋白的含量分别为：水溶性蛋白29.34%,盐溶性蛋白49.48%,不溶性蛋白15.54%;SDS-PAGE电泳分析显示,水溶性蛋白的分布量分布范围较广,在200-29.0ku之间;盐溶性蛋白条带主要分布在200ku和44.3ku处;不溶性蛋白的分子量较小,蛋白条带集中在60-20.1ku。冷冻干燥得到水溶性、盐溶性和不溶性蛋白粉,其蛋白含量分别为65.55%、45.76%和64.02%,必需氨基酸占总氨基酸的比例分别为41.6%、43.05%和37.71%。pH对水溶性蛋白的溶解性影响不明显,在pH2.0-10.0范围内,其溶解度均高于72%,但pH对盐溶性蛋白的溶解性和乳化性的影响比较明显,在pH4.0,蛋白的溶解性和乳化活性最差。

Water-soluble protein,salt soluble protein and insoluble protein were separated using chemical method from Tilapia meat in this study,and nutritional,functional properties and molecular weight of three proteins were determined.The results showed that the proportion of water-soluble protein,salt soluble protein and insoluble protein component in total protein from Tilapia meat were 29.34%,49.48% and 15.54%.Studies of SDS-PAGE showed that water-soluble protein strips distributed widely between 200 ku and 29.0 ku and salt-soluble protein strips displayed at 200 ku and 20 ku.Micromolecule insoluble protein distributed between 60 ku and 20.1 ku.Protein content of water-soluble,salt soluble and insoluble protein powder by freeze drying were 65.55%,45.76% and 64.02%,and essential amino acids content were 41.6%,43.05% and 37.71%.No obvious effect of pH value on solubility of water-soluble protein was detected,and the solubility was above 72% under pH range from 2.0 to 10.0.However effect of pH value on solubility and emulsifying properties of salt soluble protein was obvious,and the solubility and emulsifying ability were the lowest at pH value 4.0.