脉冲电场对大豆分离蛋白溶液表面性质的影响  

Effect of Pulsed Electric Field Treat ment on Surface Properties of Soy Protein Isolate Solutions

作　　者：曾新安[1] 刘燕燕[1] 

机构地区：[1]华南理工大学轻化工研究所,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2009年第4期116-119,148,共5页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省科技计划项目(2007B080401010)

摘　　要：为了探讨高强脉冲电场（PEF）对大豆分离蛋白（SPI）溶液分散体系稳定性的影响，研究了高强脉冲电场对大豆分离蛋白溶液ξ电位、氨基酸种类和表面张力的影响．结果表明：随着脉冲场强的不断增强，10mg／L及20mg／L的SPI溶液的ξ电位绝对值呈现先增大后减小的趋势，前者的ξ电位值在场强为10kV／cm时为-27．60mV（其绝对值达到最大），后者的则在场强为20kV／cm时为-32．57mV（其绝对值达到最大），此规律与SPI溶液中带负电荷氨基酸与带正电荷氨基酸的差值的变化规律基本一致；SPI溶液的表面张力随着脉冲场强的增强先增加，而后经历一个相对稳定的阶段，在较高场强下（25～35kV／cm）又有所降低．这说明脉冲电场处理对SPI溶液的作用机理在于：高强脉冲电场处理影响了氨基酸的极性和电负性，进而影响了蛋白质分子间的相互作用，从而影响到ξ电位和溶液稳定性．In order to reveal the effect of high-intensity pulsed electric field （PEF） treatment on the stability of the dispersion system of soy protein isolate （SPI） solutions, the ξ potential, the types of amino acids and the surface tension were investigated, with 10mg/L and 20 mg/L SPI solutions as the samples. The results indicate that （1） with the increase of PEF intensity, the absolute values of ξ potential of the two SPI solutions first increase and then decrease; （2） the ξ potential of 10 mg/L SPI solution reaches -27.60 mV with a maximum absolute value at a PEF intensity of 10 kV/cm, while that of 20 mg/L solution reaches - 32. 57 mV with a maximum absolute value at 20 kV/cm ; （3） the variation of ξ potential accords with that of the content difference Dn/p between the negatively- charged amino acids and the positively-charged amino acids; and （4） with the increase of PEF intensity, the surface tension of SPI solutions first increases and then decreases at 25 - 35 kV/cm after a constant stage. It is thus concluded that PEF treatment affects the polarity and electronegativity of amino acids and further affects the interaction among protein molecules, thus resulting in the variation of ξ potential and solution stability.

关 键 词：高强脉冲电场 大豆分离蛋白 ξ电位 表面张力 氨基酸分析 

分 类 号：TS205.9[轻工技术与工程—食品科学]