两种工艺提取的白玉菇蛋白理化性能比较

Comparison of Physicochemical Properties of White Hypsizygus marmoreu Protein Extracted by Two Methods

白玉菇风味与营养俱佳,蛋白含量丰富。为充分开发利用白玉菇蛋白资源,本研究采用传统碱法和超声辅助两种方式提取蛋白质,并对其吸油性、持水性、溶解性、起泡性、乳化性等理化特性进行分析。结果表明,超声辅助提取使蛋白的提取率上升到31.4%,比传统碱法提高8%。热学实验表明,超声提取蛋白最大失重速率温度为311.4℃,传统碱法提取蛋白为334.8℃。傅里叶变换红外分析发现,传统碱法提取使白玉菇蛋白的α螺旋减少,无规则卷曲增加。以大豆分离蛋白为参照,展开理化性能实验,发现在非中性或盐离子浓度0.5 mol/L时,两种提取工艺的白玉菇蛋白乳化性和乳化稳定性与大豆分离蛋白差异不显著,pH相同时,两种提取工艺的白玉菇蛋白持水性、乳化稳定性差异不显著。在相同NaCl浓度下,两种提取工艺的白玉菇蛋白溶解性、起泡稳定性和乳化稳定性差异不显著。在25~65℃区间内,不同提取方法的白玉菇蛋白的吸油性与大豆分离蛋白差异不显著。在此区间内,不同提取方法的白玉菇蛋白溶解性和起泡性均随温度的变化呈先增长后降低的趋势。

The white Hypsizygus marmoreu has good flavor and nutrition,and is rich in protein.To fully develop the white Hypsizygus marmoreu protein resources,protein was extracted by traditional alkali method and ultrasonic assisted method.The protein’s physicochemical properties such as oil absorption,water holding,solubility,foamability,emulsification were analyzed.The results showed that ultrasound-assisted extraction increased the extraction rate of protein to 31.4%,which was 8%higher than the traditional alkaline method.Thermal experiments showed that the maximum weight loss rate of protein extracted by ultrasound was 311.4℃,and that of protein extracted by traditional alkali was 334.8℃.Fourier transform infrared analysis showed that theα-spiral structure decreased while the irregular curly structure increased for the protein extracted by traditional alkali method.Compared with the soybean protein isolate(SPI),at non neutral pH or the salt ion concentration of 0.5 mol/L,there was no significant difference for the emulsifying ability and stability between white Hypsizygus marmoreu protein and SPI.At the same pH,there was no significant difference in water retention and emulsification stability between the two extraction processes.At the same NaCl concentration,no significant difference was observed between the solubility,foam stability and emulsification stability.Within 25~65℃,the oil absorption and foaming stability of white Hypsizygus marmoreu protein showed no significant difference between that of SPI.In this range,the solubility and foamability of white Hypsizygus marmoreu protein increased firstly and then decreased with the change of temperature.