米渣酶解工艺及其蛋白等电点测定

Enzymolysis of residue of rice and determination of its protein isoelectric point

以米渣为原料,按照生物酶工程技术,先对米渣进行适度酶解,确定用复合胰蛋白酶进行限制性酶解,其工艺条件为:酶量1%,温度50℃,固液比1∶5(W/V),pH8,酶解时间3h;利用酸碱沉降法对米渣酶解物的等电点进行了连续细化测定,其结果为:米渣蛋白液在不同pH下的沉淀曲线中出现两个明显波峰,说明至少存在两种不同等电点的蛋白质,在等电点为2.8时,其最大沉淀率和提取度分别为31.70%和19.02%;而在等电点为8.6时,其最大沉淀率和提取度则分别为17.78%和10.67%,该结果为进一步研究米渣蛋白的提取和改性工艺提供了重要的参考。

Using residue of rice as raw material and according to the technology of biology enzyme engineering, firstly,residue of rice was appropriate enzymolysis. Then using comb-parenzyme, the optimization conditions were：enzyme addition 1% , temperature 50℃,the ratio 1：5 （W/V）, pH 8, reaction time 3h. Using the method of acid-base precipitation to in series of zoom determination of the protein isoelectric point of residue of rice,the results were.the protein liquid of residue of rice had two obviously wave in its precipitation curve at different pH, indicated that there were two different protein at least which was in different isoelectric point,one isoelectric point was 2.8,the most precipitation rate and extraction degree were 31.70% and 19.02%, but another isoelectric point was 8.6,the most precipitation rate and extraction degree were 17.78% and 10.67%. The results give the important reference to the technology of protein extract and reshape in the follow research of residue of rice.