超高压处理对大豆拉丝蛋白特性的影响

Effects of High Pressure Processing Treatment on Properties of Drawing Soy Protein

本文研究了超高压处理对大豆拉丝蛋白特性的影响,以达到改善其再加工特性的目的。实验利用不同超高压处理条件(200~600 MPa,10~30 min)对大豆拉丝蛋白进行处理,采用傅里叶变换红外光谱、紫外吸收光谱和内源荧光光谱分析超高压对大豆拉丝蛋白结构的影响,并通过持水力、表面相对疏水性、游离巯基含量的变化研究超高压对大豆拉丝蛋白功能特性的影响。结果表明:随着压力和时间的增加,β-折叠、无规则卷曲相对含量上升,大豆拉丝蛋白的二级结构向着无序化方向进行;同时蛋白质三级结构伸展,内部疏水基团暴露量增多,但过大的压力和过长的时间则会使得疏水基团重新包埋。400 MPa、10 min时,大豆拉丝蛋白的持水力、游离巯基含量以及表面相对疏水性达到最大值,分别比对照组高32.87%、41.57%、15.66%。综上,适当条件的超高压处理有利于提高大豆拉丝蛋白再加工特性,这为超高压技术应用于大豆拉丝蛋白的生产提供参考。

In this study,the effects of high pressure processing treatment on the properties of drawing soy protein were evaluated in order to improve its reprocessing characteristics.Drawing soy protein was treated under different high pressure conditions(200~600 MPa for 10~30 min).After that,Fourier transform infrared(FTIR)spectroscopy,ultraviolet(UV)absorption spectroscopy and endogenous fluorescence spectroscopy were employed to characterize the effect of high pressure processing on the structure of drawing soy protein.The trends of water holding capacity,surface hydrophobicity and free sulfhydryl content were used as indices to evaluate the effect of high pressure processing on the functional properties of drawing soy protein.The results showed that the relative contents ofβ-sheets and random coil increased with the increase of pressure and dwell time,showing the transition of secondary structure from an ordered to a disordered state.Meanwhile,the tertiary structure of the protein was highly stretched,facilitating the exposure of hydrophobic groups initially buried inside,but the the exposed hydrophobic groups were re-buried with increasing pressure or time.At 400 MPa for 10 min,the water holding capacity,free sulfhydryl content and surface hydrophobicity of drawing soy protein reached the maximum,which were 32.87%,41.57%and 15.66%higher than those of the control group,respectively.In conclusion,high pressure processing treatment under appropriate conditions could be beneficial to improve the reprocessing characteristics of drawing soy protein,providing a reference for the application of high pressure processing technology in the production of drawing soy protein.