超高压处理对苦杏仁分离蛋白结构和致敏性的影响

苦杏仁中含有多种生物活性组分和营养素，具有较高的营养价值，但苦杏仁具有致敏性，过敏人群食用含有苦杏仁的食品后可能会产生过敏的风险。为探究超高压处理对苦杏仁分离蛋白结构和致敏性的影响，对杏仁分离蛋白进行不同压力处理，并利用圆二色谱、外源荧光光谱和酶联免疫吸附实验对其空间结构和致敏性进行表征。结果表明：苦杏仁分离蛋白100~500 MPa压力处理苦杏仁分离蛋白900 s后，苦杏仁分离蛋白其二级结构未发生显著变化。随着压力强度和保压时间的增加，苦杏仁分离蛋白的三级结构展开，荧光强度增加，疏水性基团暴露，表面疏水性逐渐增大，致敏性显著降低。苦杏仁分离蛋白致敏性的降低，可能是苦杏仁的过敏原构象表位发生了变化。该研究结果对开发安全的苦杏仁食品和饮料具有重要意义。

Effect of Ultra-High Pressure on Structure and Immunoreactivity of Bitter Apricot Kernel Protein Isolate

Bitter apricot kernel contains various bioactive components and nutrients and can be used as value-added food ingredients. However, it is also an allergen which may cause risk to allergic people if they consume foods containing bitter apricot kernel.To investigate the impact of ultra-high pressure on the structure and immunoreactivity of bitter apricot kernel protein isolate, the spatial structure and allergenicity under different pressures were detected by circular dichroism, fluorescence spectroscopy and enzyme linked immunosorbent assay(ELISA). The results demonstrated that ultrahigh pressure treatment at 100~500 MPa for 900 s insignificantly changed the secondary structure of bitter apricot kernel protein isolate. However, with the increase of pressure intensity and processing time, the tertiary structure of bitter apricot kernel protein isolate was unfolded and the hydrophobic groups were thus exposed, which led to the increase of fluorescence intensity and surface hydrophobicity and the decrease of immunoreactivity. The reduced immuno- reactivity of bitter apricot kernel protein isolate was possibly due to the changes of conformational epitopes causing food allergy. This study may provide important implications for the development of safe bitter apricot kernel food and beverage products.