提取方法对金针菇菌根蛋白特性的影响

Effects of Extracting Methods on Properties of Proteins from Root of Flammunlina velutipes

以金针菇下脚料菌柄基部为原料,采用碱法和超声辅助碱法两种方式制备蛋白质,研究不同方法制备的蛋白的特性,以期为更好地应用于食品加工业提供理论依据。金针菇蛋白分子质量主要分布在24~35 ku,45~50 ku和70~120 ku等区间,含有8种必需氨基酸,符合FAO/WHO的理想蛋白质模式。碱法提取蛋白中蛋氨酸和半胱氨酸为第1限制性氨基酸,超声辅助提取蛋白的限制性氨基酸为亮氨酸。两种方法提取蛋白的组成单元均以α-螺旋和β-折叠为主,碱法提取蛋白和超声辅助提取蛋白的热变性温度分别为73.07,73.45℃。碱法提取蛋白疏水性、起泡性较好,可用在甜点、肉制品中。超声辅助提取蛋白的溶解性、乳化性较好,可用于饮料、汤料、蛋糕等食品中。

Proteins in base of Flammulina velutipes stipe was extracted respectively by alkali extraction and ultra- sound-assisted extraction. The properties of proteins prepared by different methods were investigated with the purpose of providing a theoretical basis for the better application in food processing. The molecular weight of the extracted protein of Flammulina velutipes mainly distributed in 24-35, 45-50, 70-120 ku area. Flammulina velutipes proteins contained eight essential amino-acids and which was accorded with FAO/WHO ideal protein system. According to the nutritional evalua- tion amino acid score, the first limited amino acid was methionine and homoeysteine in alkali extraction proteins, while that was leueine in ultrasound-assisted extraction protein. The mainly composition unit of two methods extraction proteins were both α- helix and β- folding. The distortion temperature of proteins respectively were 73.07, 73.45 ℃, Alkali extraction proteins were better in terms of hydrophobie, foaming capacity and were therefore available in dessert and meat products. Ultrasound-assisted extraction proteins were better in terms of solubility, emulsifiability so were available in the drink, soup, cake and other food.