花生壳论文：花生壳中木犀草素的提取分离

花生壳论文：花生壳中木犀草素的提取分离

【中文摘要】花生壳中除含有碳水化合物和粗纤维物质外,还含有多种黄酮类化合物。木犀草素是其中主要的黄酮类物质,具有抗菌消炎、解痉祛痰、抗氧化、抗肿瘤等多种药理活性。花生壳是一种价廉且可再生的天然资源,如能提取并分离其中的有效成分木犀草素,

将该产物用于药物或保健食品生产,具有广阔的市场应用前景。本文就酶预处理-醇提联合工艺,探讨了酶解液pH值、酶解温度、酶解时间、酶用量对花生壳中黄酮成分木犀草素提取效果的影响。实验结果显示,最优酶预处理提取工艺条件为:pH值5.4、酶解温度50℃、酶解时间1.5 h、酶用量0.10%。在该最优预处理条件下,木犀草素的提取得率达到2.83 mg·g-1。同时本文依据Fick第二定律,对醇溶液提取过程建立了提取动力学模型。通过实验测得的木犀草素提取得率随提取时间变化的数据,推算出速率常数（k）、活化能（Ea）及有效扩散系数（D）等动力学参数值,为木犀草素的提取工艺设计和操作条件的优化提供了一定的理论依据。利用柱层析分离纯化技术,研究了聚酰胺树脂对花生壳中木犀草素静态吸附的热力学和动力学特征。实验测得的吸附等温线符合Langmuir吸附等温式,并利用热力学函数

关系式计算得到吸附焓（ΔH）、自由能（ΔG）及吸附熵（ΔS）,结果表明该吸附过程是自发进行且伴随放热的物理吸附过程。同时采用拟一级反应和拟二级反应模型描述了吸附动力学数据,得出拟二级吸附动力学模型能更好地描述聚酰胺树脂对木犀草素的吸附行为。另外,

通过动态吸附实验测定了穿透曲线,得到聚酰胺树脂对木犀草素的动态吸附容量（Q）为0.2817 mg·g-1,总传质系数（KFav）为0.0570 s-1,传质长度（Za）为28.40 cm,为木犀草素生产的放大操作提供了实验和理论依据。经不同比例的醇溶液梯度洗脱分离花生壳提取液中的木犀草素,确定75%乙醇溶液洗脱效果最佳。采用分子印迹技术,以木犀草素为模板分子,α-甲基丙烯酸（MAA）为功能单体,乙二醇二甲基丙烯酸酯（EDMA）为交联剂,偶氮二异丁腈（AIBN）为引发剂,丙酮为致孔剂,通过本体聚合法,制备了木犀草素分子印迹聚合物（MIP）。通过静态吸附实验,研究了该聚合物对木犀草素的选择性和吸附性能。结果表明,印迹聚合物对模板分子产生了特殊的印迹效应,对木犀草素

具有明显的选择性和识别能力,而空白聚合物（NIP）没有。通过将该分子印迹聚合物装入固相萃取柱,确定先用55%甲醇溶液为淋洗液清洗,再用甲醇洗脱溶液洗脱,能最大程度分离出木犀草素-芹菜素混合黄酮类化合物中的木犀草素。同时将该分子印迹聚合物应用于花生壳提取物中木犀草素的分离,在合适的淋洗和洗脱条件下,能选择性分

离出目标产物木犀草素,其纯度可由2.51%提高到93.40%,回收率为92.84%。

【英文摘要】Peanut shell contains not only carbohydrates and crude fibre, but also a variety of flavonoids substances. Luteolin is a main flavonoid in the peanut shell, with antibacterial, antiinflammatory, antispasmodic, expectorant, antioxidant, antitumor and other pharmacological activities.

As a cheap renewable resource, peanut shell has wide application prospects and marketable value in the fields of raw medicine and food material if we can extract and purification luteolin.In this paper enzyme pre-treatment reflux extraction joint method was used to extract luteolin in the peanut shell. The effect of the enzyme solution pH, hydrolysis temperature, hydrolysis time, cellulose volume on the yield of total luteolin from peanut shell were studied. The best conditions of extraction were concluded as follows: pH 5.4, enzyme temperature of 50℃, hydrolysis time of 1.5 h, cellulose volume of 0.10%. Under the optimal conditions, it can be included that the luteolin yield is 2.83 mg·g-1. And the mass transfer kinetics of luteolin extraction was established on the basis of the Fick’s Second Law during reflux extraction process. Experimental datas of luteolin extraction were fitted respectively, and calculated some kinetics function values, such as k、Ea、D and so on. Therefore, the modified model can provide the valuable theory foundation for the technical designing and operational condition of luteolin extraction optimization.By column chromatography separation technology, thermodynamics and dynamics of adsorption of luteolin from peanut shell on polyamide were studied. The equilibrium