储藏时间对大米蛋白质组分的影响

Effect of different storage time on protein composition of rice

主要研究储藏时间对大米4种蛋白质亚基组分变化的影响。实验以市售普通大米为初始原料,在高温高湿的环境下进行储藏,以5个不同储藏时间段(0、24、48、72、96h)的大米为实验对象,对不同储藏时间段大米的4种蛋白质(清蛋白、球蛋白、醇溶性蛋白和谷蛋白)进行SDS-PAGE电泳实验,分析大米储藏过程中4种蛋白质各自亚基组成的变化。研究发现,储藏过程中水溶性清蛋白的亚基组成变化很大,有低分子质量亚基发生了类似于酶的作用,即先分解后合成,平均分子质量增加;盐溶性球蛋白减少较明显;醇溶性蛋白质组分基本无变化,十分稳定;碱溶性蛋白质高、中分子质量的亚基都存在分解和合成现象,并且在储藏96h后出现一个分子质量约为22ku的亚基。

The effect of different storage time on four protein composition of rice were investigated.A type of commercially available new rice was storaged in a condition of high temperature and high relative humidity（45℃ and 95% RH）for 96 h.Four kinds of protein（albumin,globulin,glutelin and prolamin）were extracted from five stored periods（0,24,48,72and96h）of accelerated aging rice and analysed by using SDS polyacrylamide gel electrophoresis（SDS-PAGE）.During the storage period,albumin subunit composition changed greatly,and one low molecular weight band showed a status of first decomposition at the outset and then composition after a period of storage just like an enzyme,the average molecular weight increased;globulin content reduced obviously;prolamin constituent changed little.Some of glutelin＇s high and medium molecular weight bands were decomposed or composed.And a new glutelin subunit of 22 ku molecular weight appeared after 96 hstorage.