摘要
目的:研究不同温度和料液比下临泽小枣粗多糖(Lingze jujube polysaccharide,LZJP)提取传质动力学,并分析多糖理化性质和显微结构。方法:采用水提醇沉法得到LZJP,以Fick第一定律建立LZJP提取动力学模型,获得速率常数、相对萃余率、活化能和半衰期等模型参数。采用DEAE-52纤维素柱和Sephadex G-100凝胶色谱柱分别纯化得到LZJP3和LZJP4,采用傅里叶变换红外光谱进行多糖官能团结构分析,并利用扫描电子显微镜和原子力显微镜观察不同多糖组分表面显微结构。结果:实验数据与动力学模型计算值良好吻合,且提取过程符合一级动力学模型,该提取过程的活化能为19.266 kJ/mol,表明水提醇沉法可有效地提取LZJP。傅里叶变换红外光谱结果表明,LZJP3和LZJP4均为酸性多糖,且为β-吡喃型多糖。原子力显微镜观察结果显示,LZJP3分子排列疏松、大小形状均一;LZJP4有少量的分子球状聚集体和大量的分散体,大小不均匀。扫描电子显微镜观察结果显示LZJP3多糖呈片状,表面形貌光滑略有破损;LZJP4为分枝状,表面呈现出干燥的褶皱状。
The extraction of polysaccharides from Linze jujube fruit(LZJP)by hot extraction followed by ethanol precipitation was studied.The physicochemical properties and microstructure of LZJP were analyzed.Based on Fick's first law of diffusion,the mass transfer kinetics of polysaccharides at different temperatures and solid to solvent ratios were investigated and a kinetic model was established for the extraction process.The key model parameters including rate constant,relative extraction rate,activation energy and half-life were calculated.The experimental data were found to be well fitted to the kinetic model and the extraction process obeyed first-order kinetics with an activation energy of 19.266kJ/mol,indicating that hot water extraction could enable effective extraction of polysaccharides from Linze jujube fruit.Purification of LZJP by DEAE-52 cellulose and Sephadex G-100 column chromatography yielded homogenous polysaccharides LZJP3 and LZJP4,respectively.Fourier transform infrared spectra showed that LZJP3 and LZJP4 were acidic polysaccharides andβ-pyran polysaccharides.Atomic force microscopy indicated that LZJP3 molecules were loosely arranged with uniform size and shape and that LZJP4 had a small amount of globular aggregates and a large number of dispersions with unequal sizes.Scanning electron microscopy showed that LZJP3 was flaky with a smooth but slightly damaged surface;LZJP4 was branched with a wrinkled and dry surface.
作者
徐也
刘晓风
王永刚
任海伟
刘继超
张璇
范文广
杨明俊
XU Ye;LIU Xiaofeng;WANG Yonggang;REN Haiwei;LIU Jichao;ZHANG Xuan;FAN Wenguang;YANG Mingjun(School of Life Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2019年第3期1-8,共8页
Food Science
基金
国家自然科学基金地区科学基金项目(31760028
81660581)
关键词
红枣
多糖
动力学
傅里叶变换红外光谱
原子力显微镜
Ziziphus jujuba Mill.
polysaccharides
kinetics
Fourier transform infrared spectroscopy
atomic force microscope
