不同pH条件下米谷蛋白的理化及结构特性研究

Studies on physicochemical and structural properties of rice glutelin at different pH values

为探索溶解大米蛋白的最适pH值,扩大其应用范围,表征了不同pH(pH 3.0,4.0,7.0)条件下大米蛋白中主要成分——米谷蛋白的理化及结构性质。结果表明,与中性条件下相比,酸性条件下米谷蛋白的溶解度和结构性质发生了明显改变,pH 7.0时米谷蛋白分子结合紧密,形成庞大的分子聚集体,溶解度仅(6.24±1.25)%;而在酸性条件下,米谷蛋白逐渐分散,分子间二硫键断裂,呈现分散疏松的小分子体状态,pH 3.0时其溶解度最高,达到(72.47±2.36)%。

Among cereal proteins, rice proteins are hypoallergenic,rich in essential amino acids and easily digestible etc.While their lower solubilities under neutral conditions limit their applications in food industry.In present study,the physicochemical and structural properties of rice glutelin at different pH values(pH 3.0,4.0 and 7.0)were characterized to explore the optimum pH value to dissolve rice protein and expand its application range.The results showed that,compared to the neutral condition,the solubility and structural properties of rice glutelin were changed significantly under the acidic conditions.The protein solubility was only(6.24±1.25)% at pH 7.0,for under neutral condition,protein molecules linked together to form huge molecular aggregates.However,under acidic conditions,protein molecules dissociated and intermolecular disulfide bonds ruptured gradually.Therefore,the protein solubility increased under the acidic condition,and it reached(72.47±2.36)% at pH 3.0.