蛋白质分子聚集状态对大豆蛋白溶胀性能的影响

通过分子间作用力和分子聚集状态研究了大豆分离蛋白 (SPI)和大豆浓缩蛋白 (SPC)的功能与性质 .SPI 1、SPI 2和SPI 3以及SPC 1和SPC 2的溶出活化能分别为 1 5.63 ,2 4 .2 0 ,1 7.3 1 ,1 6.1 3和 4 .3 1kJ/mol.SPI 2在蛋白质分子之间形成二硫键 ;SPC 2在蛋白质分子间通过二硫键结合成为聚集体 ,而聚集体之间以很弱的范德瓦尔斯力结合 ;SPI 1 ,SPI 3和SPC 1具有较高的粘度且在模拟肉制品中的性能较好 .结构分析表明 ,蛋白质分子形成聚集体 ,但聚集体之间通过疏水键和氢键结合 .导致大豆蛋白产品的分子间作用力和分子聚集状态不同的主要原因是加热以及闪蒸过程中工艺条件的不同 .

Effect of Molecule Aggregation on the Swelling Ability of Soy Protein Preparations

The swelling ability of soy protein isolates (SPI) and concentrates (SPC) was studied as a function of protein interaction and molecule aggregation. The activating energy of dissolving protein in water, which give a measure of the molecular interaction, was determined by Arrhenious plotting of dissolving rate vs 1/T and the values are 15.63, 24.20, 17.31, 16.13, and 4.31 kJ/mol for SPI 1, SPI 2, SPI 3,SPC 1 and SPC 2 respectively. SPI2 and SPC2 have lower viscosity when hydrated than SPI 1, SPI 3 and SPC 1. It is found that, for a good swelling ability, protein aggregates which are formed via disulfide cross linking of molecules, should interact each other by hydrophobic force which is strong enough to avoid being broken down on hydrating but will not be so large to hinder the swelling of protein network.