Off-flavors remain a major hurdle in expanding the use of soy protein isolate (SPI) in mainstream food applications. The complexity in solving this problem arises from the presence of protein-bound precursors in SPI. Among the most predominant sources of off-flavors in SPI is the residual amount of phospholipids that contain polyunsaturated fatty acids (PUFAs). Autoxidation of PUFAs generates several classes of volatile compounds that contribute to the beany, grassy, or green odor of SPI. In addition, several polyphenolic compounds, such as isoflavones, saponins, phenolic acids, etc., impart bitter and astringent tastes to SPI. Traditional methods for removing protein-bound precursors from SPI and their limitations are reviewed. The most notable trade-off of conventional methods is the loss of protein functionality to some degree. Therefore, pursuit of gentler treatments to overcome SPI off-flavor has been the focus of industry and academia alike. Novel approaches that employ β-cyclodextrin to remove both SPI-bound precursors and volatile compounds are described.

中文翻译：

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大豆分离蛋白中的异味前体及其去除新策略。

异味仍然是在主流食品应用中扩大使用大豆分离蛋白（SPI）的主要障碍。解决此问题的复杂性是由于SPI中存在蛋白结合的前体。SPI中最主要的异味来源是含有多不饱和脂肪酸（PUFA）的磷脂残留量。PUFA的自氧化会生成几类挥发性化合物，这些化合物会导致SPI产生豆腥味，草味或绿色气味。另外，几种多酚化合物，例如异黄酮，皂角苷，酚酸等，赋予SPI苦涩的味道。综述了从SPI中去除蛋白质结合前体的传统方法及其局限性。传统方法最明显的折衷是蛋白质功能性在一定程度上丧失。所以，寻求更温和的疗法来克服SPI异味一直是工业界和学术界关注的焦点。描述了采用β-环糊精同时去除SPI结合的前体和挥发性化合物的新型方法。