大米蛋白质中砷分布规律研究

米蛋白在婴幼儿产品和高端产品领域应用具有广阔前景,然而重金属易于在稻米蛋白质中富集增加了米蛋白制品的安全风险。以砷污染大米为研究对象,通过Osborne法连续提取大米中清蛋白、醇溶蛋白、谷蛋白和球蛋白,用SDS-PAGE、MALDI-TOF-MS等方法对蛋白进行表征,并运用红外光谱法,紫外扫描分析研究了各蛋白的光谱吸收特征。利用ICP-MS法测定重金属含量得到不同蛋白结合砷的能力差异,得出砷与清蛋白是优势的结合形态。通过氨基酸组成分析并比对正常大米的氨基酸组成,推测砷可能与蛋白中的脯氨酸结合紧密。

The distribution of As in rice protein

Rice protein has broad prospects for use in infant and baby products and high-end products. However, the accumulation of heavy metals in rice proteins increases the safety risk of rice protein products. In this paper, As-contaminated rice was used as the research object, and the albumin, prolamin, gluten and globulin in rice were continuously extracted by Osborne method. The four proteins were characterized by SDS-PAGE, MALDI-TOF-MS, etc., and the spectrum absorption character of each protein were studied by infrared spectroscopy and UV spectroscopy. The difference in the ability of different proteins to bind As was determined by ICP-MS method. It was found that As and albumin were the dominant binding complex in rice. Finally, by analyzing the amino acid composition and comparing with that of normal rice, it is speculated that As probably binds tightly to proline in the protein. This study responds to the national quality grain engineering construction and provides a theoretical basis for the development of high-quality rice protein products and rice As reduction technology.