藕渣纤维素的碱法提取工艺优化及性能测定

Optimization of alkali extraction process and determination of properties of cellulose from lotus root residue

中文关键词:  藕渣  纤维素  响应面  碱法提取  表征

英文关键词:lotus root residue  cellulose  response surface  alkaline extraction  representation

中文摘要:

      目的 优化藕渣纤维素的提取工艺, 研究该纤维素的形貌结构及理化特性。方法 以纤维素的含量为指标, 以NaOH浓度、Na2SO3浓度和提取温度为考察因素进行单因素实验, 结合Box-Behnken响应面实验对提取工艺进行优化。并对提取藕渣纤维素进行组分分析和形貌结构表征。结果 响应面优化结果显示, NaOH浓度、Na2SO3浓度和提取温度对藕渣纤维素的含量均具有显著影响(P<0.05)。确定最佳提取工艺条件为NaOH浓度1.25 mol/L、Na2SO3浓度1.00 mol/L、提取温度80℃, 此条件下样品纤维素含量84.31%, 淀粉含量为0.80%、蛋白质含量为2.75%。红外光谱数据表明纯化样品中半纤维素和木质素的特征峰明显减弱, 具有典型的纤维素峰, 证明该方法有效提取了纤维素样品; X射线衍射结果表明藕渣和提取的藕渣纤维素衍射曲线有较大的差别, 且藕渣纤维素的衍射峰位置与已报道纤维素基本一致, 证明所使用的提取方法并未改变藕渣纤维素的结晶结构; 扫描电镜分析表明木质素和半纤维素被除去后纤维素裸露表面发生聚集, 形成褶皱结构; 热分析表明藕渣纤维素的最佳热分解温度为265℃, 所提取的纤维素具有较好的热稳定性。结论 通过系列工艺优化实验获得了最优的提取工艺条件, 所提取的纤维素具有较高的纯度, 且与棉花纤维素的理化特性一致。

英文摘要:

      Objective To optimize the extraction process of cellulose from lotus root residue and study the morphology, structure and physicochemical properties of cellulose. Methods Taking the cellulose content as the index, NaOH concentration, Na2SO3 concentration and extraction temperature as the investigation factors to carry out a single-factor experiment, and optimize the extraction process in combination with the Box-Behnken response surface experiment. And the composition analysis and morphological structure characterization of the extracted lotus root residue cellulose were analyzed. Results The response surface optimization results showed that the concentration of NaOH, the concentration of Na2SO3 and the extraction temperature had significant effects on the content of cellulose in lotus root residue (P<0.05). The optimal extraction process was determined as NaOH concentration of 1.25 mol/L, Na2SO3 concentration of 1.00 mol/L and extraction temperature of 80℃. Under these conditions, cellulose content was 84.31%, starch content was 0.80% and protein content was 2.75%. Infrared spectroscopy data showed that the characteristic peaks of hemicellulose and lignin in the purified samples were significantly weakened, and the cellulose peaks were typical, which proved that the cellulose samples were effectively extracted. The results of X-ray diffraction showed that there was a great difference between the diffraction curves of lotus root residue and cellulose from lotus root residue and that the diffraction peak position of cellulose from lotus root residue was basically the same as that of reported cellulose, which proved that the extraction method used did not change the crystalline structure of cellulose from lotus root residue. Scanning electron microscopy analysis showed that after lignin and hemicellulose were removed, the bare surface of cellulose gathered to form a fold structure. Thermal analysis showed that the optimal thermal decomposition temperature of cellulose from lotus root residue was 265℃, and the extracted cellulose had certain thermal stability. Conclusion The optimum extraction conditions are obtained through a series of process optimization experiments, the extracted cellulose has high purity and is consistent with the physicochemical properties of cotton cellulose.