玉米芯半纤维素提取、乙酰化改性及结构表征  

Extraction,Acetylation Modification and Structure Characterization of Hemicelluloses from Corncob

作　　者：彭俏 赵四九 范国枝 程群鹏 宋光森 PENG Qiao;ZHAO Sijiu;FAN Guozhi;CHENG Qunpeng;SONG Guangsen(School of Chemical and Environmental Engineering,Wuhan Polytechnic University,Wuhan 430023,China)

机构地区：[1]武汉轻工大学化学与环境工程学院,湖北武汉430023

出　　处：《食品工业科技》2022年第11期45-51,共7页Science and Technology of Food Industry

基　　金：武汉市科技局应用基础前沿专项(2020020601012263);湖北省科技厅中央引导地方科技发展专项(2019ZYYD059)。

摘　　要：以玉米芯为原料提取半纤维素,并对所提取的玉米芯半纤维素进行乙酰化改性。采用超声辅助碱法提取玉米芯半纤维素,浓硫酸(H_(2)SO_(4))和单质碘(I_(2))共催化玉米芯半纤维素进行乙酰化改性;采用红外光谱(IR)、热重分析(TGA)和核磁共振光谱(NMR)对玉米芯半纤维素及其乙酰化产物进行表征。玉米芯半纤维素得率和提取率分别为33.7%和81.0%,其中半纤维素含量为85.3wt%,乙酰化产物产率和取代度(DS)分别为84.6%和1.27。超声辅助有效缩短了碱法提取玉米芯半纤维素的时间,且玉米芯半纤维素得率和提取率均得到提高。H_(2)SO_(4)和I_(2)是半纤维素乙酰化改性的高效共催化体系,IR和NMR结果表明半纤维素被成功改性,改性产物中存在乙酰基,TGA分析表明乙酰化产物热稳定性增加,且DS值适中,有望进一步用于制备可生物降解的食品包装材料。Hemicellulose was extracted from corncob and further modified by acetylation.Ultrasonic-assisted alkali method was employed for the extraction,in which sulfuric acid(H_(2)SO_(4))and elemental iodine(I_(2))were used as co-catalyst for the acetylation of hemicellulose,respectively.Corncob hemicellulose and its acetylated products were characterized by infrared spectroscopy(IR),thermogravimetric analysis(TGA)and nuclear magnetic resonance(NMR).The yield and extraction rate of corncob hemicellulose were 33.7%and 81.0%,and the hemicellulose content reached 85.3wt%.The acetylation of corncob hemicellulose gave 84.6%yield and 1.27 degree of substitution(DS),respectively.The separation of hemicellulose from corncob using alkali method was effectively shortened by ultrasonic assistance,and the yield and extraction rate of corncob hemicellulose were improved.Concentrated sulfuric acid(H_(2)SO_(4))and elemental iodine(I_(2))were effective cocatalyst for the acetylation of corncob hemicellulose.The results of IR and NMR showed that hemicelluloses were acetylated successfully,and TGA revealed that the thermal stability of the acetylated hemicellulose was improved.Moreover,the DS value of the acetylated product was moderate.Therefore,the acetylated product is expected to be used to prepare biodegradable materials for food packaging.

关 键 词：超声辅助 玉米芯 半纤维素 碱法提取 乙酰化 结构表征 

分 类 号：TS206.4[轻工技术与工程—食品科学]