Supplementary Material for: Boiling and Pressure Cooking Impact on IgE Reactivity of Soybean Allergens

Background: Soybean is one of the 8 foods that causes the most significant rate of food allergies in the USA and Europe. Thermal processing may impact on the allergenic potential of certain foods. We aimed to investigate modifications of the IgE-binding properties of soybean proteins due to processing methods that have been previously found to impact on the allergenicity of legumes such as peanut. Methods: Soybean seeds were subjected to different thermal processing treatments. To evaluate their impact on the IgE-binding capacity of soybean proteins, individual sera from 25 patients sensitized to soybean were used in in vitro immunoassays. Detection of specific soybean allergens in untreated and treated samples was carried out with specific monoclonal and polyclonal antibodies. In vivo studies of skin prick testing (SPT) were also performed. Results: The IgE reactivity of soybean was resistant to boiling up to 30 min, and this treatment had a higher impact when applied for 60 min. Treatment that combined heat and pressure produced a fragmentation of proteins in both soluble and insoluble fractions that went along with a decreased capacity to bind IgE and reduced the SPT wheal size. However, allergens such as 7S globulins survived this treatment. Conclusions: Thermal-processing methods able to attenuate the capacity of soybean proteins to bind IgE may contribute to the improvement of food safety and could constitute a potential strategy for the induction of tolerance to soybean.背景：大豆是欧美地区引发食物过敏率最高的八种食品之一。热加工可对部分食品的致敏潜力产生影响。本研究旨在探究经此前被证实可影响花生等豆科植物致敏性的加工方式处理后，大豆蛋白结合免疫球蛋白E（IgE）的特性变化。 方法：将大豆种子施以不同热加工处理。为评估各处理对大豆蛋白IgE结合能力的影响，选取25名大豆致敏患者的个体血清开展体外免疫测定；采用特异性单克隆抗体与多克隆抗体，对未经处理及经处理的样品中的特异性大豆过敏原进行检测。此外还完成了皮肤点刺试验（Skin Prick Test，SPT）的体内研究。 结果：大豆的IgE反应性可耐受最长30分钟的煮沸处理，当煮沸时长延长至60分钟时，该煮沸处理的影响更为显著。热压联合处理可使可溶性与不溶性组分中的蛋白质发生裂解，同时伴随IgE结合能力下降及皮肤点刺试验风团面积减小。但诸如7S球蛋白类的过敏原仍可耐受该热压处理。 结论：可减弱大豆蛋白IgE结合能力的热加工方式，有助于提升食品安全，或可成为诱导大豆食物耐受的潜在策略。