酶-碱法提取碎米蛋白工艺研究

以精米加工副产物的碎米为原料,采用酶法富集-碱法浸提工艺对碎米蛋白质进行提取。首先采用α-淀粉酶对碎米进行液化预处理,以利于碎米中蛋白质组分的富集。在酶解温度95℃、pH7.5、固液比1∶15、α-淀粉酶用量20U/g、水解时间150min条件下,碎米原料液化率达到61.4%,经离心分离后的沉淀作为下游碱法提取蛋白质的原料。在单因素实验基础上,以提取率为指标,设计正交实验对碱法提取工艺条件进行了优化。结果表明,最佳浸提工艺参数为:NaOH浓度0.06mol/L、料液比1∶5(w/v,g/mL)、提取时间5h、温度50℃,在此最佳条件下,碎米蛋白提取率达到86.26%。酶-碱复合法集酶法富集与碱法浸提为一体,为碎米蛋白的生产及碎米资源的高值化利用提供了相关依据。

Optimization of enzyme-alkali assisted extraction of rice protein from broken rice

Broken rice,byproduct of refined rice manufacture was used as raw material to extract its protein by enzymatic enrichment and alkali extraction methods.Firstly,α-amylase was applied to pretreat the broken rice for enriching protein elements.Under the condition that 95℃,pH7.5,solid-liquid ration 1∶15,α-amylase content 20U/g and hydrolysis time 150 min,liquefaction rate of broken rice was up to 61.4%,which was use for the next alkaline extraction after centrifugation.Based on the extraction rate of protein(BRP),the single factor and orthogonal analysis method were designed to optimize alkaline extraction conditions.The results showed that the best parameter for protein extraction were as follows:NaOH 0.06mol/L,solid-liquid ratio(g/mL) 1∶5,extraction time 5h and extraction temperature 50℃.The extraction ration of BRP was up to 86.26% under the optimized process.Enzyme-alkali assisted extraction method integrated the enzymatic enriching and alkali extraction,which would provide some theoretical foundation for the production of BRP and the value-increment application of broken rice resources.