过氧化脂质对分离蛋白凝胶性质的影响

以大豆为原料,通过常温下正己烷浸提去油,得到高脂肪氧合酶活力的豆粕,采用不同干热程度处理得到酶活不同的豆粕,进而以碱溶酸沉法制备分离蛋白。发现不同脂质过氧化程度的豆粕提取出的分离蛋白性质差异比较显著。不同蛋白氯仿-甲醇提取液的荧光测定证实了过氧化脂质的存在。浊度反映了蛋白中不溶性聚集体的含量。凝胶的流变、质构和渗透性测定表明了不同程度蛋白聚集的凝胶性质的变化,而凝胶的扫描电镜图也显示了凝胶微观结构随灭酶程度的变化。

Effect of peroxidized lipids in defatted soybean flour on the gelling properties of soybean protein isolate

Soybean flour was defatted by hexane at room temperature,and high lipoxygenase(LOX) activity flour was attained.Different LOX activity flour was obtained with varying dry heating time.Soybean protein isolate was prepared with these defatted flour.The great different properties were found in these proteins.Fluorescence of choloroform-mehtanol extract from protein certified the existence of peroxidized lipids.Turbidity reflected the content of insoluble aggregates contained in protein.The gelling properties were changed with different aggregated protein extent,and the scanning electron microscope showed the changes at microstructure.