蒜头果木质素提取及成分分析

采用一般碱法、超声波辅助和微波辅助从蒜头果壳和枝中提取木质素,分别测定了蒜头果壳和枝中木质素含量及木质素的提取率,并对所提取木质素进行红外和紫外光谱分析。克拉森木素定量法测得蒜头果壳和枝中木质素质量分数分别为44.41%±0.65%和34.57%±0.52%,在碱浓度0.5 mol/L、碱液量30 mL/g、超声波处理时间1 h、水浴温度40℃的提取工艺条件下,蒜头果壳和枝的木质素提取率分别为45.21%±0.59%和63.78%±0.73%。紫外和红外光谱显示超声波辅助方法提取的木质素保持了木质素原有结构,存在明显的愈疮木基和紫丁香基苯环结构;并通过黏度法比较了3种不同提取方法所得木质素的相对分子质量。

Analysis of Chemical Component of Lignin Extract from Malania oleifera

Lignins were extracted from Malania oleifera shell and branch by traditional alkaline method,ultrasound-assisted method and microwave-assisted method.The yields and the contents of the lignins from Malania oleifera shell and branch were determined.Meanwhile,the lignins obtained were structurally analyzed by infrared(IR) and UV spectroscopy.Determined by Klason method,the contents of lignin in Malania oleifera shell and branch were 44.41%±0.65% and 34.57%±0.52% respectively.The extraction rates of lignins reached 45.21%±0.59% and 63.78%±0.73% respectively from Malania oleifera shell and branch under the conditions of ultrasound-assisted extraction at 40 ℃ water bath for 1 h with 0.5 mol/L KOH water as the solvent and the solvent/material ratio of 30∶ 1(mL/g).UV and IR spectral analyses show that the lignin extracted by ultrasound-assisted method remained its original structure,and there were many syringyl and guaiacyl groups in Malania oleifera shell and branch.The relative molecular weight of the lignins extracted by the three different extraction methods was compared by adopting the viscosity method.