提取方法对薏仁碎米蛋白氨基酸组成及功能特性的影响  

Effect of extraction methods on amino acid composition and functional properties of rice-coix seed protein

作　　者：杨华连 陈莉[1,2] 卢红梅 贾青慧[2,3] 杨新 安家静 YANG Hua-lian;CHEN Li;LU Hong-mei;JIA Qing-hui;YANG Xin;AN Jia-jing(Guizhou Province Key Laboratory of Fermentation Engineering and Biopharmacy,Guizhou University,Guiyang550025;School of Liquor and Food Engineering,Guizhou University,Guizhou University,Guiyang550025;School of Chemistry and Chemical Engineering,Guizhou University,Guiyang550025)

机构地区：[1]贵州大学贵州省发酵工程与生物制药重点实验室,贵阳550025 [2]贵州大学酿酒与食品工程学院,贵阳550025 [3]贵州大学化学与化工学院,贵阳550025

出　　处：《食品科技》2018年第11期262-268,共7页Food Science and Technology

基　　金：贵州省科技合作计划项目(LH[2015]7668)

摘　　要：以碱提酸沉法和酶法提取得到的薏仁碎米蛋白为对象,研究提取方法对薏仁碎米蛋白氨基酸组成及功能特性的影响,测定碱提酸沉法和酶法提取得到的薏仁碎米蛋白在溶解性、乳化性、起泡性及泡沫稳定性、吸油性等功能特性方面的差异,并与大豆蛋白粉进行比较。结果表明,碱提酸沉法和酶法提取得到的薏仁碎米蛋白的氨基酸存在较大差异,其总量分别为537、467.55 mg/g,其中必需氨基酸含量分别为205.9、183.66 mg/g。在不同p H条件下,碱提蛋白的溶解性、乳化性及乳化稳定性、持水性在不同程度上略低于酶提蛋白,在等电点p H5.2处各功能性质最差;碱提蛋白与酶提蛋白的溶解性、持水性随温度变化趋势一致,皆呈先增后减之势,分别在50、60℃达到峰值;在Na Cl浓度为0.2 mol/L处,酶提蛋白和碱提蛋白的氮溶解指数(NSI)皆达到最大值。酶提蛋白的功能性质在一定程度上优于碱提蛋白,且薏仁碎米蛋白在乳化性、持水性、吸油性等功能特性方面优于大豆蛋白粉,可作为一种优质蛋白替代大豆蛋白粉达到改善食品品质的目的,具有一定的开发利用价值。The rice-coix seed protein extracted by the method of alkali extraction, acid precipitation and enzymatic extraction was used as the object to study the effect of extraction methods on amino acid composition and functional properties of rice-coix seed. The differences in solubility, emulsifying properties, foaming properties, foam stability, oil absorption, and other functional properties of ricecoix seed protein obtained by alkaline extraction and acid precipitation and enzymatic extraction were determined, and compared with soybean protein powder. The results showed that there were significant differences in the amino acids compestiton of rice-coix seed protein extracted by the method of alkali extraction acid precipitation and enzymatic extraction. The total amount of amino acids was 537 mg/g and 467.55 mg/g, respectively. The essential amino acid content was 205.9 mg/g, 183.66 mg/g respectively. Under different pH conditions, the solubility, emulsifying, emulsifying stability and water holding capacity of the alkaline extract protein are slightly lower than that of the enzyme extract protein, and the functional properties are the worst at the isoelectric point pH 5.2. The solubility and water holding capacity of enzyme-extracted proteins were consistent with the trend of temperature, and they all increased at first and then decreased, reaching their maximum values at 50 ℃ and 60 ℃, respectively; at the NaCl concentration of 0.2 mol/L. The nitrogen solubility index(NSI) of the extract protein by two methods reached the maximum value. The functional properties of the enzyme-extracting protein are better than that of the alkali-extracted protein to a certain degree, and the rice-coix seed protein is superior to the soybean protein powder in the emulsifying property, water-holding property, oil-absorption property. It can used as a kind of high quality in some food fields to replace soybean protein powder to improve food quality, therefore, it has certain value for development and utilization.

关 键 词：薏仁碎米蛋白 提取方法 氨基酸组成 功能特性 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]