胡麻籽分离蛋白的溶解性与起泡性研究

Solubility and Foaming Properties of Falxseed Protein Isolate

为促进胡麻籽分离蛋白在食品工业中的应用,研究了pH值、盐浓度、蛋白质浓度等因素对其水溶性、起泡性和泡沫稳定性的影响。pH值对胡麻籽分离蛋白溶解度的影响呈典型的V形曲线。NaCl浓度为0.4mol/L前后胡麻籽分离蛋白表现出明显的盐溶与盐析效应。在0.1%～0.8%范围内,提高蛋白质浓度能增强起泡性与泡沫稳定性。在等电点附近,胡麻籽分离蛋白的起泡性最差但却具有最强的泡沫稳定性。NaCl对胡麻籽分离蛋白的起泡性的影响与其对溶解性的影响有相同的趋势。蔗糖能提高胡麻籽分离蛋白的泡沫稳定性,但当浓度高于5%时,对起泡性有负面影响。

Effects of factors including pH, NaCl, protein concentration on solubility and foaming properties of flaxseed protein isolate were investigated in this study. Results indicated that the influence of pH on solubility of protein isolate showed a typical V-shaped curve pattern. Significant salt-in and salt-out effects were observed when NaCl concentration was lower than 0.4 mol/L or higher than that. Within the range of 0.1% to 0.8 %, an increment in protein concentration resulted in enhancements in foaming capacity and foaming stability. Lower foaming capacity was found at isoelectric point （pI）, which proved to be higher foaming stability. NaCl concentration displayed the similar pattern in influencing foaming properties and solubility of protein isolate. Addition of sugar could increase foaming stability of flaxseed protein isolate while reduce its foaming capacity at the concentration above 5%.