盐法提取豌豆分离蛋白凝胶特性及影响因素

采用一种低变性的提取方法--盐法提取豌豆分离蛋白并使用流变仪测定其流变特性，结果表明：盐法豌豆分离蛋白最低凝胶形成质量浓度是5.5 g/100 mL，豌豆分离蛋白凝胶点与蛋白质量浓度无相关性。豌豆分离蛋白凝胶点随加热速率增加呈上升趋势。较高的加热和冷却速率能够增加反应终点储能模量（G’）和耗能模量（G”）值，因而降低凝胶强度。盐法豌豆分离蛋白凝胶韧性随蛋白质量浓度的增加而增大，且蛋白质量浓度与G’、G”值之间存在乘幂规律。tanδ值随蛋白质量浓度升高而降低，当蛋白质量浓度高于5 g/100 mL时，弱凝胶开始形成；当蛋白质量浓度高于7 g/100 mL时，tanδ值几乎保持恒定，表明凝胶弹性在此范围内基本恒定。比较盐法和商业豌豆分离蛋白凝胶性质后发现：盐法豌豆分离蛋白具有更好的凝胶性。

Gel-Forming Characteristics of Pea Protein Isolate and Their Affecting Factors

A novel low-denaturation extraction method, salt method, was applied to extract pea protein isolate from
commercial pea flour and the gelation characteristics of this protein isolate were determined by a rheometer. The minimum
gelation concentration of salt extracted pea protein isolate (PPIs) was 5.5 g/100 mL. No correlation was noted between
the gelation point and concentration of PPIs, but the gelling point showed a tendency of increasing with heating rate.
Meanwhile, higher heating and cooling rates resulted in decreased final G’ (storage modulus) and G” (loss modulus), thus
reducing the gel stiffness. Higher protein concentration induced greater gel stiffness, and higher G’ and G” values. It was
found that there were power law relationships between protein concentration and either G’ or G” values. Tan delta value
decreased with increasing protein concentration, and weak gel was formed when protein concentration was greater than
5 g/100 mL; however, when protein concentration was greater than 7 g/100 mL, tan delta kept almost constant, which
indicated that gel elasticity was constant within this concentration range. When comparing gelation properties of PPIs to
commercial pea protein isolate (PPIc), the gel stiffness of PPIs was much greater than that of PPIc. Therefore, PPIs may
have greater market prospect than PPIc in emulsified meat products.