凝胶电泳法研究蒸汽爆破对高温豆粕中蛋白质结构的影响

Effect of steam flash- explosion on protein structure of high- temperature soybean meal using gel electrophoresis method

采用3种凝胶电泳研究了高温豆粕中蛋白质结构在蒸汽爆破处理过程中的变化。原态凝胶电泳图谱表明蒸汽爆破处理豆粕中蛋白质的聚集体发生解离,蛋白质分子呈连续性分布;还原和非还原SDS-PAGE蛋白染色图谱显示经蒸汽爆破处理后,蛋白质的各个亚基和AB亚基聚集体减少,且出现蛋白质新聚集体;还原SDS-PAGE糖染色电泳图谱显示蒸汽爆破处理豆粕和高温豆粕中较多的蛋白质和糖类发生了共价结合;分离蛋白中总糖与蛋白质含量的比值证明蒸汽爆破处理促进了糖与蛋白质的共价结合,并且该反应与蒸汽爆破处理的压力和时间有关。

The changes of protein structure of high - temperature soybean meal treated by steam flash - explosion （SFE） were studied using methods of native -polyacrylamide gel electrophoresis （PAGE）, re- ducing and non -reducing sodium dodecyl sulphate -polyacrylamide gel electrophoresis （SDS -PAGE）. The native -PAGE results indicated that after SFE treatment, the protein aggregates were dissociated and the molecular distribution of protein was polydisperse. The protein staining of reducing and non - reduc- ing SDS -PAGE results indicated that after SFE treatment, the contents of each subunit and AB subunit aggregates of protein reduced, and new protein aggregates formed. The Schiff staining of reducing SDS - PAGE results showed that many proteins of soybean meal after SFE treatment and high - temperature soy- bean meal combined covalently with carbohydrate due to Maillard reaction. The ratio of total carbohydrate to protein of soybean protein isolate （SPI） indicated that SFE could promote the covalent bond of carbo- hydrate with protein, and the reaction was related to the pressure and time of SFE.