南美蟛蜞菊叶蛋白提取方法筛选

Evaluation of leaf protein extraction methods from Wedelia trilobata

【目的】筛选出适合南美蟛蜞菊叶蛋白的提取方法和条件,为其蛋白饲料资源化利用提供技术支持。【方法】通过正交试验分别优化酸加热法、碱加热法、盐析法和有机溶剂法提取南美蟛蜞菊叶蛋白的工艺条件,并对比4种方法的提取效果,确定最佳提取工艺。【结果】4种方法提取的南美蟛蜞菊叶片粗蛋白含量排序为:盐析法(15.18 mg/g)>酸加热法(9.97 mg/g)>碱加热法(9.79 mg/g)>有机溶剂法(7.21 mg/g)。其中,盐析法的最适提取条件为氯化钠质量浓度30%、絮凝时间10 min;酸加热法的最适提取条件为絮凝温度60℃、pH 3、絮凝时间2 min;碱加热法的最适提取条件为絮凝温度25℃、pH 7、絮凝时间2 min;有机溶剂法的最适提取条件为乙醇体积分数20%、絮凝时间10 min。絮凝温度对酸加热法和碱加热法提取效率有显著影响(P<0.05),溶液浓度对盐析法和有机溶剂法提取效率有极显著影响(P<0.01)。【结论】综合比较4种方法提取南美蟛蜞菊叶蛋白的效果,确定盐析法是提取南美蟛蜞菊叶蛋白的最适方法,其提取效率高、操作简便、蛋白质活性保持较好,适用于实验室提取和工业生产。

[Objective]The leaf protein extraction method and conditions from Wedelia trilobata were selected and op-timized, which provided technical support for the exploitation and utilization of W. trilobata as protein feed resources.[Method]Using orthogonal experiment,four leaf protein extraction methods including acid heating method,alkali heating method, salting out method and organic solvent method were optimized and extraction results were compared.Hence the optimal extraction conditions from W. trilobata were determined. [Result]According to the extracting leaf crude protein content from W. trilobata,the four methods were ranked as follows：salting out method （15.18 mg/g）〉acid heating method（9.97 mg/g）〉alkaline heating method（9.79 mg/g）〉organic solvent method（7.21 mg/g）. The optimum extraction conditions for salting out method were as follows：concentration of sodium chloride solution was 30%,flocculation time was 10 min. For acid heating method,the optimum extraction conditions were flocculation temperature 60 ℃,pH 3 and floccula-tion time 2 min. The optimum conditions for alkaline heating method were flocculation temperature 25 ℃,pH 7 and floccu-lation time 2 min. The optimum conditions for organic solvent method were 20% ethanol volume fraction and 10 min for flocculation. Flocculation temperature had significant effect on extraction efficiency for acid heating method and alkali heat-ing method（P〈0.05）,and concentration of extracting solution had extremely significant effect on extraction efficiency for salting out method and organic solvent method（P〈0.01）. [Conclusion]By comparing the four methods,salting out method was determined as the optimal method for extracting leaf protein from W. trilibata because of its high extraction efficiency, simple operation,high protein activity which enabling it suitable for laboratory extraction and industrial production.