Abstract In this study an alternative mild fractionation process for the extraction of soy protein is investigated; aqueous fractionation, in which oil extraction and intensive washing steps are omitted. Moreover, a pH adjustment is proposed instead of the conventional neutralization step. The mildly fractionated soy protein fractions (SPFs) showed higher protein and oil content compared to commercial soy protein isolate. The process retained the proteins’ native state. SPFs adjusted at pH 4.5 and 5.5 (close to pI) formed a powdery texture, resulting in larger size particles after dispersion in water. Despite their low nitrogen solubility index, water holding capacity and viscosity, when mixed with flour these SPFs presented the highest G* values. A flaky texture and reversed properties were observed with SPF adjusted at pH away from the pI. The range of properties achieved exhibits new routes in creating soy protein ingredients with desired functionality, avoiding over-processing due to post-treatment modifications.

中文翻译：

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受加工pH影响的轻度分级大豆蛋白的功能特性

摘要 在这项研究中，研究了一种用于提取大豆蛋白的替代性温和分级工艺；水分馏，其中省略了油提取和强力洗涤步骤。此外，建议调整 pH 值来代替传统的中和步骤。与商业大豆分离蛋白相比，轻度分离的大豆蛋白组分 (SPF) 显示出更高的蛋白质和油含量。该过程保留了蛋白质的天然状态。在 pH 值 4.5 和 5.5（接近 pI）下调节的 SPF 形成粉状质地，在水中分散后产生更大尺寸的颗粒。尽管它们的氮溶解度指数、持水能力和粘度较低，但当与面粉混合时，这些 SPF 表现出最高的 G* 值。在将 SPF 调整为远离 pI 的 pH 值时，观察到片状质地和相反的特性。