糖类对苜蓿叶蛋白中SOD的冻干保护作用

Protective Effect of Sugar on SOD in Alfalfa Leaf Protein during Freeze Drying

研究海藻糖(0.1%,0.2%,0.3%)、蔗糖(0.1%,0.2%,0.3%)、乳糖(0.1%,0.2%,0.3%)和蔗糖+乳糖(0.1%+0.2%,0.15%+0.15%,0.2%+0.1%)对苜蓿叶蛋白中超氧化物歧化酶(SOD)活性的影响及苜蓿(Medicago sativaL.)叶蛋白的化学成分,探讨适合的冻干保护剂。结果表明:糖类冻干保护剂在一定浓度范围内对苜蓿叶蛋白中SOD活性具有保护作用,其中海藻糖处理(0.1%、0.2%和0.3%)、0.1%和0.2%乳糖处理、混合糖处理SOD活性保存率均显著高于对照(P<0.05),其中0.3%海藻糖处理和1∶1比例的蔗糖和乳糖组合处理保护效果最好;0.3%蔗糖和0.3%乳糖处理对SOD未起到保护作用。苜蓿叶蛋白中富含蛋白质,而且各种氨基酸种类齐全,组成比例较为平衡,其中赖氨酸含量比较丰富。

The protective effects of trehalose （0. 1%, 0. 2%, and 0. 3%）, sucrose （0. 1%, 0. 2%, and 0.3%）, lactose （0.1%, 0.2%, and 0.3%）, and mixture of sucrose and lactose （0.1%＋0.2%, 0.15%＋ 0.15%, 0.2%＋0.1%） on SOD activity and the chemical composition of alfalfa leaf protein were studied for choosing protective agent for freeze drying. The results show that the activity of SOD in alfalfa leaf protein could be protected by sugar protective agent within a given range of sugar concentrations. The activity remain rate of SOD in alfalfa leaf protein treated with trehalose （0.1%, 0.2%, and 0.3%）, lactose （0.1% and 0.2%）, and mixed sugar were significantly higher than the control （P〈0.05） ; treatments of trehaloes （0.3%） and the mixed sugar （1 ： 1） were better than others; The 0.3% sucrose and 0.3% lactose had no protective effect. Alfalfa leaf protein had complete amino acids with balanced composition and was rich in lysine.