燕麦蛋白理化性质研究

Study on physicochemical properties of oat protein

以燕麦为原料,对碱提酸沉法提取的燕麦蛋白进行理化性质研究,分析了燕麦蛋白的溶解性、起泡性质、乳化性质、分子量分布、氨基酸组成和热变性。结果表明,在接近燕麦蛋白等电点处,溶解度最低,随pH增大溶解度逐渐升高。在等电点处,燕麦蛋白的起泡性最差,泡沫稳定性最好;偏离等电点燕麦蛋白的起泡性随着pH的增大先增加后减小,而泡沫稳定性稍有下降。燕麦蛋白的乳化性随pH的升高先减小后增大,在等电点附近乳化性最低;而乳化稳定性的变化规律正好相反。燕麦蛋白分子量分布主要集中在18.4~25.0 kDa和25.0~35.0 kDa 2个区间。燕麦蛋白氨基酸种类齐全,配比合理,是一种优质植物蛋白。运用DSC测出了燕麦蛋白的变性温度为102℃。

In this study, oat proteins extracted from oat flour by alkali extraction and acid precipitation were studied for its physicochemical properties（solubility, foaming properties, emulsifying properties, amino acid compositions and thermal denaturation）.The results showed that the solubility was the lowest at the isoelectric point, and then it increased gradually with an increase of pH. At the isoelectric point, the foaming ability of the oat protein was the worst, while the foam stability was the best. After the isoelectric point, the foaming property increased firstly and then decreased with an increase of pH, while the foam stability was slightly decreased. The emulsifying property of was decreased firstly and then increased with an increase of pH and the emulsifying property was the lowest at the isoelectric point, while the change rule of emulsion stability was the opposite. The denaturation temperature of the oat protein was determined to be 102℃ by DSC. The oat protein is a high quality vegetable protein with complete amino acid and reasonable proportion and its molecular weight is mainly concentrated upon 18.4-25.0 kDa and 25.0-35.0 kDa.