玉米芯半纤维素的制备及表征

Extraction and characterization of hemicelluloses from maize cob

采用碱法提取,以玉米芯半纤维素得率为指标,利用单因素试验考察了料液比、提取温度、提取时间对玉米芯半纤维素得率的影响,研究了玉米芯半纤维素的制备工艺,并采用扫描电镜、红外光谱、热重分析对半纤维素进行了表征。结果表明,料液比与提取时间对半纤维素得率的影响较大,在料液比为1∶25(g/mL)、提取温度为80℃、提取时间为3.0 h的条件下,玉米芯半纤维素的得率达28.2%;扫描电镜图显示玉米芯半纤维素表面大部分为松散结构,红外光谱图显示分子间存在着β-糖苷键连接,热重分析表明其热分解范围在200~300℃。

The alkali solution extraction method was applied to maize cob powder processing.Based on the single factor experiment,the effects of three independent variables,namely,ratio of solid to liquid,extraction temperature and extraction duration on the yield of extracted hemicelluloses were evaluated,and hemicelluloses were then characterized by scanning electron microscopes(SEM),Fourier transform infrared spectroscopy(FT-IR)and thermogravimetric analyzer(TG).The results showed that the impact of ratio of solid to liquid and the extraction duration on the yield of extracted hemicelluloses was obvious.The yield of the hemicelluloses was up to 28.2%under the following conditions:the ratio of solid to liquid was 1∶25(g/mL),extraction temperature was 80℃and extraction duration was 3.0 h.SEM image indicated that the surface structure of maize cob hemicelluloses was loose.FT-IR spectra showed that there wereβ-glyosidic bands structure among hemicelluloses.Thermal analysis suggested that the decomposition temperature of hemicellulose was 200~300℃.