Department of Biotechnology, Central University of Rajasthan, Ajmer, India.
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia.
J Food Biochem. 2022 Oct;46(10):e14369. doi: 10.1111/jfbc.14369. Epub 2022 Aug 9.
Purified soya bean proteins (glycinin and conglycinin) are known to form amyloid-like aggregates in vitro at a higher temperature. Soya beans (chunks) are textured proteinaceous vegetables made from defatted soya flour by heating it above 100°C and extruding under high pressure. Therefore, it was assumed that subjecting the soya bean proteins to high temperatures raises the possibility of forming amyloids or amyloid-like protein aggregates. Hence, the present study aimed to examine the presence of amyloid-like protein aggregates in soya beans. The isolated protein aggregates from hydrated soya beans displayed typical characteristics of amyloids, such as the red shift in the absorption maximum (λ ) of Congo red (CR), high Thioflavin T (ThT), and 8-Anilinonapthalene-1-sulfonate (ANS) binding, and fibrilar morphology. Furthermore, these aggregates were found to be stable against proteolytic hydrolysis, confirming the specific property of amyloids. The presence of amyloid-like structures in soya beans raises concerns about their implications for human nutrition and health. PRACTICAL APPLICATIONS: Protein aggregation has usually been considered detrimental. The traditional food-processing conditions, such as thermal processing, are associated with protein denaturation and aggregation. The formation of ordered protein aggregates with extensive β-sheet are progressively evident in various protein-rich foods known as amyloid, which expands food safety concerns. Instead, it is also associated with poor nutritional characteristics. The present study concerns the presence of amyloid-like protein aggregates in widely consumed native soya beans, which are manufactured by extensive heat treatment of defatted soy flour. Although there is no indication of their toxicity, these aggregates are found to be proteolytically resistant. The seminal findings in this manuscript suggest that it is time to adapt innovative food processing and supplementation of bioactive molecules that can prevent the formation of such protein aggregates and help maximize the utilization of protein-based nutritional values.
纯化的大豆蛋白（glycinin 和 conglycinin）已知在较高温度下在体外形成类似淀粉样的聚集物。大豆（块状物）是由脱脂大豆粉加热至 100°C 以上并在高压下挤压而成的质地蛋白蔬菜。因此，人们认为使大豆蛋白经受高温会增加形成淀粉样蛋白或类似淀粉样蛋白聚集物的可能性。因此，本研究旨在检查大豆中是否存在类似淀粉样蛋白的聚集物。从水合大豆中分离出的蛋白聚集物显示出淀粉样蛋白的典型特征，例如刚果红（CR）吸收最大值（λ）的红移、高硫黄素 T（ThT）和 8-苯胺萘-1-磺酸盐（ANS）结合以及纤维状形态。此外，这些聚集物被发现对蛋白水解具有抗性，证实了淀粉样蛋白的特异性。大豆中存在类似淀粉样结构引起了人们对其对人类营养和健康影响的关注。实际应用：蛋白聚集通常被认为是有害的。传统的食品加工条件，如热处理，与蛋白变性和聚集有关。在各种富含蛋白的食物中，有序的蛋白聚集物与广泛的β-折叠逐渐变得明显，这些聚集物被称为淀粉样蛋白，这扩大了食品安全问题。相反，它也与较差的营养特性有关。本研究涉及广泛食用的天然大豆中类似淀粉样蛋白聚集物的存在，这些大豆是通过对脱脂大豆粉进行广泛的热处理制造的。尽管没有表明它们有毒性，但这些聚集物被发现具有抗蛋白水解性。本文的主要发现表明，现在是时候采用创新的食品加工和生物活性分子的补充方法来防止这种蛋白聚集物的形成，并有助于最大限度地利用基于蛋白的营养价值。
