琥珀酰化改性花生蛋白研究

Modification of peanut protein by succinylation

为考察琥珀酰化改性因素对花生蛋白改性效果及结构性质的影响,采用单因素试验、响应面试验分析花生蛋白质量浓度、琥珀酸酐添加量、反应温度对改性花生蛋白酰化度与产率的影响,确定最优琥珀酰化改性条件。通过红外光谱、电子显微镜、氮溶解指数评价琥珀酰化改性花生蛋白的结构性质。结果表明:花生蛋白质量浓度、琥珀酸酐添加量是显著影响因素;最佳改性条件为花生蛋白质量浓度58.5 g/L、琥珀酸酐添加量为花生蛋白质量的19.55%、反应温度49℃,在最佳条件下改性花生蛋白酰化度与产率分别为(82.82±0.59)%和(76.89±0.74)%;引入琥珀酰基改变了花生蛋白的分子结构,使蛋白质分子由折叠趋向伸展,蛋白质聚集体尺寸减小;改性花生蛋白的溶解性得到明显改善。

In order to investigate the impacts of succinylation modification factors on modification effect and structure of peanut protein,the effects of mass concentration of peanut protein,dosage of succinic anhydride and reaction temperature on acylation degree and yield of the modified peanut protein were analyzed by single factor experiment and response surface methodology,and the optimal conditions of modification by succinylation were determined.The structural properties of modified peanut protein by succinylation were evaluated by infrared spectra,electronic microscope and nitrogen solubility index.The results showed that the mass concentration of peanut protein and dosage of succinic anhydride were significant factors.The optimal modification conditions were obtained as follows：mass concentration of peanut protein 58.5 g/L,dosage of succinic anhydride 19.55% of peanut protein mass and reaction temperature 49 ℃.Under these conditions,the acylation degree and yield of the modified peanut protein reached （82.82 ± 0.59） % and （76.89±0.74） % respectively.Because of the introduction of succinyl group,the molecular structure of peanut protein changed,so that the fold state inclined to extension and the size of protein aggregate shrank.The solubility of modified peanut protein was also improved notably.