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旨在为开发大豆蛋白的脱敏技术提供参考，对大豆分离蛋白（SPI）进行挤压膨化处理，对不同挤压膨化温度下SPI的抗原性、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）、氨基酸组成、溶解度、紫外吸收光谱、内源荧光光谱及表面疏水性进行分析。结果表明：随着挤压膨化温度的升高，SPI抗原性呈现先降低再升高的趋势，145 ℃时SPI的抗原性下降最为显著；SPI中抗原蛋白β-伴大豆球蛋白的α、α′、β亚基以及大豆球蛋白的酸性亚基和碱性亚基均发生明显降解；SPI的氨基酸组成、必需氨基酸含量与氨基酸总量比值无明显变化，营养性保持良好；SPI溶解度降低；氢键、二硫键、疏水相互作用均是维持SPI空间结构的分子作用力，其中氢键起主要作用；SPI的紫外光谱和内源荧光光谱均出现不同程度的红移，紫外吸收强度及荧光强度发生变化，表面疏水性显著下降，SPI的三级结构发生改变。综上，挤压膨化能够在一定程度上降低SPI的抗原性，并影响其空间结构。 In order to provide reference for the development of desensitization technology of soybean protein, the antigenicity, SDS-PAGE, amino acid composition, solubility, UV absorption spectra, endogenous fluorescence spectra and surface hydrophobicity of the soybean protein isolate (SPI) extruded at different extrusion temperatures. The results showed that the antigenicity of SPI decreased first and then increased with the increase of extrusion temperature, and the antigenicity of SPI decreased most significantly at 145 ℃. The α, α′ and β subunits of the antigen protein β-conglycinin and the acidic and basic subunits of glycinin in SPI were significantly degraded. The amino acid composition and the ratio of essential amino acids to total amino acids of SPI had no obvious change, and the nutritional characteristics of SPI remained good. After extrusion, the solubility of SPI decreased, and hydrogen bond, disulfide bond and hydrophobic interaction were the molecular forces that maintained SPI spatial structure, in which hydrogen bond played the main role. The UV and endogenous fluorescence spectra of SPI extruded showed different degrees of redshift, the UV absorption intensity and fluorescence intensity changed, the surface hydrophobicity decreased significantly, and the tertiary structure of SPI changed. In conclusion, extrusion can reduce the antigenicity of SPI to a certain extent and affect its spatial structure.

为了有效提高核桃蛋白的利用率，拓展核桃蛋白在食品领域的应用范围，采用阴离子（Cl-、PO3-4、S2O2-3、HCO-3）和阳离子（Na+、K+、Mg2+、Ca2+）对核桃蛋白进行改性，并对改性后核桃蛋白的结构与功能特性进行研究。结果显示：阴离子PO3-4、HCO-3 和阳离子Na+、Mg2+增加了核桃蛋白的巯基含量；除了Cl-和K+，其他6种离子改性核桃蛋白的二硫键含量均下降，其中HCO-3改性核桃蛋白下降最多；8种离子对核桃蛋白的亚基组成无影响；Cl-、PO3-4、Na+和Ca2+使核桃蛋白构象稳定性提高，而HCO-3会使核桃蛋白紧密程度变差；不同离子对核桃蛋白溶解度的影响存在差异；不同离子改性均提高了核桃蛋白的乳化性和乳化稳定性，其中阴离子PO3-4改性核桃蛋白的乳化性提高了2.52倍，而阳离子Na+改性核桃蛋白的乳化稳定性提高了46.22百分点；阴离子S2O2-3与阳离子Mg2+对核桃蛋白的起泡性影响最大，而Na+改性核桃蛋白的起泡稳定性最好；PO3-4改性核桃蛋白的持水性和吸油性均最高。综合来讲，Na+和Mg2+改性核桃蛋白的乳化性、乳化稳定性、起泡性和起泡稳定性相对更好。 In order to effectively improve the utilization rate of walnut protein and expand its application range in the field of food, walnut protein was modified by anions ( Cl-, PO3-4, S2O2-3, HCO-3) and cations ( Na+, K+, Mg2+, Ca2+ ), and the structure and functionality of the modified walnut protein were studied. The results showed that the anions PO3-4, HCO-3 and cations Na+, Mg2+ could increase the sulfhydryl content of walnut protein. Except Cl- and K+, the content of disulfide bonds in walnut protein treated with other six ions decreased, among which HCO-3 treated samples decreased the most. Eight ions had no effect on the subunit composition of walnut protein. The Cl-， PO3-4, Na+ and Ca2+ improved the stability of walnut protein conformation, while HCO-3 made the tightness of walnut protein worse. The effects of different ions on the solubility of walnut protein were different. The ions improved the emulsifying property and emulsion stability of walnut protein. The emulsifying property of walnut protein treated with anion PO3-4 increased 2.52 fold, while the emulsion stability of walnut protein treated with cation Na+ increased by 46.22 percentage points. The anion S2O2-3 and cation Mg2+ had the greatest effect on the foaming property of walnut protein, while the foam stability of walnut protein treated with Na+ was the best. The walnut protein treated with PO3-4 had the highest water holding capacity and oil absorption capacity. In general, the emulsifying property, emulsion stability, foaming property and foam stability of walnut protein treated with Na+ and Mg2+ are relatively better.