糖基化反应对蛋清蛋白质凝胶性的影响

Effect of Glycosylation on Gel Properties of Egg White Protein

为研究糖基化反应提高蛋清蛋白质凝胶性的机理,利用氨基酸分析仪、苯酚硫酸法、奥氏黏度计、静态激光散射仪对糖基化蛋清蛋白质氨基酸组成、总糖含量、特性黏度、粒径分布进行测定与分析。结果显示:糖基化反应可使蛋清蛋白质的凝胶强度和持水性分别提高91.7%和35.2%,且二者均在反应4d后达到最高值;糖基化处理5d后,蛋清蛋白质的赖氨酸含量相对降低28.42%,总糖含量增至2.18%;特性黏度随反应时间的延长增幅较小;糖基化蛋白粒径分布在0.1～50.0μm之间,糖基化2d内,粒径分布由小粒径峰向大粒径峰转变;糖基化2 d后,粒径分布变化不明显。

The effect of glycosylation on gel strength and water-holding capacity of egg white protein （EWP） was investigated. The change of amino acid compositions, total sugar content, and intrinsic viscosity as well as particle size distribution were detected by amino acid analyzer, phenol sulfuric acid method, and ostwald viscosimeter as well as static laser light scattering instrument. The results showed that gel strength and water-holding capacity of egg white protein were improved after glycosylation. Both of them reached to the highest value after glycosylation for four days, which revealed the improvement by 91.7% and 35.2%, respectively. The content of lysine in egg white protein exhibited a decrease by 28.42% and the content of total sugar revealed an increase by 2.18% at the fifth day during the glycosylation process. Intrinsic viscosity revealed a slight increase as the extension of treatment time. The particle size of the protein was in the range of 0.1 - 50.0 μ m and the conversion from small size protein to large size protein was observed at the first two days, and no significant change was observed during the last four days.