热效应对小麦醇溶蛋白起泡性与结构的影响  

Insight into the Impact of Heat Treatment on the Foamability and Structure of Gliadin Colloidal Particles

作　　者：王立峰[1] 朱洁 熊文飞 赵萌 袁建[1] 鞠兴荣[1] WANG LiFeng;ZHU Jie;XIONG WenFei;ZHAO Meng;YUAN Jian;JU XingRong(College of Food Science and Engineering,Nanjing University of Finance and Economics,Nanjing 210023)

机构地区：[1]南京财经大学食品科学与工程学院,南京210023

出　　处：《中国农业科学》2021年第4期820-830,共11页Scientia Agricultura Sinica

基　　金：江苏现代农业产业技术体系建设专项(JATS[2020]468);国家优质粮食工程(南京)技术创新中心项目。

摘　　要：【目的】来源于小麦面筋的醇溶蛋白由于具有较强的表面疏水性能,其通过乙醇-水溶液反溶剂制备的胶体粒子展现突出的起泡能力和稳定性。然而,小麦醇溶蛋白胶体粒子在热效应作用下的泡沫特性表现还未得到揭示。因此,为进一步推动小麦醇溶蛋白胶体粒子在真实食品体系中的应用,研究了不同加热温度和加热时间对小麦醇溶蛋白胶体粒子起泡能力和稳定性的影响。【方法】将小麦醇溶蛋白在不同温度下(50、70和90℃)分别处理15、30和60 min后,通过反溶剂法制备小麦醇溶蛋白胶体粒子,测定其起泡能力和泡沫稳定性。通过测定热处理后胶体粒子的尺寸、表面电势、蛋白溶解度的变化,借助原子力显微镜、SDS凝胶电泳、红外光谱、荧光光谱、圆二色谱、紫外光谱、DSC及小角X光散射分析热处理后的小麦醇溶蛋白表面形态及微观结构的变化规律。【结果】经热处理后的小麦醇溶蛋白胶体粒子的起泡能力和泡沫稳定性分别提高了25%和85%。随着加热温度的升高和加热时间的延长,小麦醇溶蛋白胶体粒子发生了部分聚集,粒子尺寸增加,颗粒尺寸主要分布在105—122 nm,ζ-电位降低,90℃时聚集程度更高;加热温度对蛋白溶解度无明显影响,随着加热时间的增加,蛋白的溶解度有了显著的提高;热效应使蛋白分子内部的疏水氨基酸暴露,导致了表面疏水性的增加;二硫键含量减少,游离巯基含量并无显著差异,其原因可能是醇溶蛋白在受热过程中发生了SH/SS交换反应。高温处理改变了小麦醇溶蛋白二级结构,90℃下的蛋白荧光强度降低,β-折叠含量减少,无规则卷曲含量增加,蛋白结构高度伸展,并伴随着部分去折叠。DSC结果显示小麦醇溶蛋白胶体粒子的最高能量从54.33 mW降低到3 mW左右,加热后的谱图比较平缓,蛋白质的构象随着加热时间的延长趋向于无定形态。【结论】热效【Objective】Gliadin derived from wheat gluten has strong surface hydrophobic properties, and the gliadin colloid particles prepared by ethanol-water solution anti-solvent exhibit outstanding foaming ability and stability. However, the foam properties of gliadin under the action of heat have not been revealed yet. Therefore, in order to further promote the application of gliadin particles in real food systems, the effects of different heating temperatures and heating times on the foaming ability and stability of gliadin particles were studied in this paper. 【Method】After treating the gliadin at different temperatures(50, 70 and 90℃) for 15, 30 and 60 minutes, the gliadin particles were prepared by the anti-solvent method, and the foaming ability and foam stability were measured.By measuring the size, zeta potential, protein solubility, atomic force microscopy, infrared spectroscopy, fluorescence spectroscopy, circular dichroism, ultraviolet spectroscopy, DSC and small-angle X-ray scattering of the heat-treated wheat gliadin particles, the changing law of its surface morphology and microstructure were analyzed. 【Result】The results showed that the foaming ability and foam stability of the heat-treated wheat gliadin particles increased by 25% and 85%, respectively. With the increase of the heating temperature and the extension of the heating time, the gliadin particles had partially aggregated;the particle size increases, and it mainly distributed around 105-122 nm, and the zeta potential decreases;the degree of aggregation became greater at 90℃. The heating temperature had no obvious effect on protein solubility, but the solubility of protein has been significantly improved with the increase of heating time;the thermal effect exposed the hydrophobic amino acids inside the protein molecule, resulting in an increase in surface hydrophobicity;the content of disulfide bonds decreases, and the content of free sulfhydryl groups had no significant difference. The reason might be that the SH/SS exchange react

关 键 词：小麦醇溶蛋白 起泡性 结构柔性 表面疏水性 

分 类 号：TS201.21[轻工技术与工程—食品科学]