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Abstract：
Alternative protein sources for the human diet may help overcome the growing food pressure. Plants with abundant resources and high protein content are potential sources. In this article, graded proteins and isolated proteins from Corylus mandshurica Maxim kernels were extracted by the Osborne procedure and the alkali-solution and acid-isolation method, respectively, and the contents of the five proteins, and the differences in nutritional value and structural properties of the main proteins, were investigated. Amino acid analysis revealed that the total essential amino acids in the five proteins ranged from 249.58 to 324.52 mg/g. The essential amino acid profiles in the proteins were similar to those of FAO/WHO except for the alcohol-soluble protein. The essential amino acid indices ranged from 58.59 to 72.19 and the biological values ranged from 52.16 to 66.99, and the highest nutritional indices were found for the isolate and water-soluble protein, which were 41.68 and 55.78, respectively. The molecular weight pattern distribution of the protein isolates of the Corylus mandshurica Maxim kernel was more similar to that of the water-soluble proteins by SDS-PAGE. The β-sheet and α-helix were the main secondary structures in the two protein fractions. The fluorescence spectra showed that the maximum fluorescence intensity of the two proteins and their λmax were also somewhat different. From the perspective of microscopic morphology, the two proteins are mainly compact and irregular lamellar structures, but the surface of the water-soluble protein is more flat and regular. Both proteins have good solubility, and the water-soluble protein has higher solubility. In general, the protein isolates of the Corylus mandshurica Maxim kernel and the water-soluble protein showed their potential as plant protein resources.
摘要：
人类饮食的替代蛋白质来源可能有助于克服日益增长的食物压力。植物资源丰富，蛋白质含量高，是潜在的来源。在这篇文章中,通过Osborne程序以及碱溶液和酸分离方法提取了从MandshuricaMaxim核提取的分级蛋白和分离蛋白，分别,以及五种蛋白质的含量，以及主要蛋白质的营养价值和结构特性的差异，被调查了。氨基酸分析表明，五种蛋白质中的总必需氨基酸范围为249.58至324.52mg/g。除了醇溶性蛋白质外，蛋白质中的必需氨基酸谱与FAO/WHO相似。必需氨基酸指数在58.59~72.19之间,生物学值在52.16~66.99之间,分离蛋白和水溶性蛋白的营养指数最高,分别为41.68和55.78。通过SDS-PAGE分析，山核桃核分离蛋白的分子量分布与水溶性蛋白的分子量分布更为相似。β-折叠和α-螺旋是两个蛋白质组分中的主要二级结构。荧光光谱表明，两种蛋白质的最大荧光强度及其λmax也有所不同。从微观形态来看,这两种蛋白质主要是致密和不规则的层状结构，但是水溶性蛋白质的表面更平坦和规则。两种蛋白质都有很好的溶解性,水溶性蛋白质具有较高的溶解度。总的来说,锦葵核的蛋白质分离物和水溶性蛋白质显示了它们作为植物蛋白资源的潜力。
