花生球/伴球蛋白富集组分的制备及其物化与功能特性研究

本文以低温脱脂花生粉为原料，采用冷沉法分离制备了花生球蛋白和伴球蛋白富集组分，并研究了两种组分的物化和功能特性。通过冷沉法所制备花生球/伴球蛋白富集组分的蛋白含量分别为91.27%和84.87%，蛋白的纯度分别为93.1%和71.4%。研究结果表明，该法制备的花生球蛋白富集组分相比伴花生球蛋白富集组分和花生分离蛋白，具有更低的热变性程度和更高的热稳定性。而伴花生球蛋白富集组分和花生分离蛋白相比花生球蛋白富集组分具有更加松散的三级构象和更高的表面疏水性。花生球蛋白富集组分展示了更高的溶解性（pH 6.0处除外）。乳化活性和稳定性按从高到低的排序为花生球蛋白富集组分、伴花生球蛋白富集组分和花生分离蛋白。伴花生球蛋白富集组分的溶解性在pH值3.0~6.0的范围内变化最为敏感并表现出在中性条件下最佳的凝胶特性。

Preparation of Arachin/Conarachin Rich Fractions and Analysis of Their Physicochemical and Functional Properties

The arachin/conarachin-rich fractions were isolated from the defatted peanut flour by cryoprecipitation, and the physicochemical and functional properties of both fractions were studied. The protein contents of arachin/conarachin fractions prepared by cryoprecipitation were 91.27 and 84.87%, respectively, while the corresponding protein purities were 93.1 and 71.4%, respectively. The study results indicated that the arachin-rich fraction prepared by this method had a lower degree of thermal denaturation and higher thermal stability compared with the conarachin-rich fraction and peanut protein isolate (PPI). Conarachin-rich fraction and PPI had a more loose tertiary conformation and surface hydrophobicity compared to the arachin-rich fraction. The arachin-rich fraction showed the highest solubility in the entire pH range except at pH 6.0; however, the solubility of the conarachin-rich fraction was the most susceptible to change in pH value between 3.0 and 6.0. The arachin-rich fraction showed the highest emulsifying activity and stability, followed by conarachin-rich fraction and PPI. The conarachin-rich fraction exhibited the best heat-induced gelation properties at neutral pH, followed by the arachin-rich fraction and PPI.