连续相变萃取灵芝多糖动力学球状模型的建立及其结构特征  

Dynamic Analysis Spherical Model of the Continuous Phase Transition Extraction and Structural Characteristics for Polysaccharide from Ganoderma lucidum

作　　者：张军 段杉[1] 全丽金 张杏思 曹庸[1] ZHANG Jun;DUAN Shan;Quan Li-jin;ZHANG Xing-si;CAO Yong(College of Food Sciences,South China Agricultural University,Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods,Guangdong Province Engineering Research Center for Bioactive Natural Products,Guangzhou 510642,China)

机构地区：[1]华南农业大学食品学院,广东省功能食品活性物重点实验室,广东省天然活性物工程技术研究中心,广东广州510642

出　　处：《食品工业科技》2020年第17期114-120,共7页Science and Technology of Food Industry

摘　　要：根据中草药浸提机制和非稳态扩散理论对灵芝多糖(GLP)的连续相变萃取过程动力学进行研究,研究不同温度、流速和时间下GLP传质动力学,并对多糖结构特征进行分析。以灵芝子实体为原料,采用连续相变萃取技术得到GLP,基于Fick第二定律建立GLP溶出动力学球状模型方程并研究了萃取过程的热力学特性。利用高效凝胶渗透色谱法(HPGPC)研究多糖分子量分布、傅里叶变换红外光谱(FT-IR)对多糖官能团结构进行分析及扫描电子显微镜(SEM)观察多糖形态结构。最佳萃取工艺条件为:温度为373.15 K、流速为28 L/h,时间为190 min,在此条件下GLP得率为2.04%。动力学球状模型方程为ln[(C∞-C)/C∞]=π^2Dt/R^2+ln(π^2/6),速率常数k、相对萃余率y=(C∞-C)/C∞及半衰期方程y=-7.440 x+2864.4等动力学参数,试验数据与动力学模型计算值吻合良好(R^2>0.94),萃取过程符合一阶扩散动力学模型。HPGPC结果表明GLP分子量分布范围为1.35×10^3~2.26×10^7 Da。FT-IR结果表明GLP为β-吡喃型多糖,SEM显示GLP由碎片状聚集体所组成,呈现出褶皱状。该动力学模型可为灵芝多糖连续相变萃取工艺条件优化以及深层次研究奠定理论基础。The continuous phase transition extraction was applied to extract Ganoderma lucidum polysaccharides(GLP)based on the mechanism of extraction and unsteady diffusion,the structural characteristics of the polysaccharide were analyzed.Based on Fick’s second law,the mass transfer kinetics model of polysaccharides dissolution was established at different temperatures,flow rates and different extraction time.The molecular weight distribution,functional groups on the polysaccharide structure and observation of morphology of the polysaccharide were studied by high performance gel permeation chromatography(HPGPC),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The results showed that optional extraction of GLP was temperature of 373.15 K,flow rate of 28 L/h and extraction time of 190 min,the yield of GLP was up to 2.04%.The diffusion kinetic spherical model of the continuous phase transition extraction for polysaccharide was fitted to the equation of ln[(C∞-C)/C∞]=π^2Dt/R^2+ln(π^2/6).The relative kinetics parameters including rate constant k,relative extraction rate y=(C∞-C)/C∞,half-life linearity y=-7.440 x+2864.4 and other kinetic parameters were calculated,the thermodynamics properties were investigated,respectively.The kinetics equation for extraction of polysaccharides from Ganoderma lucidum was fitted with the first-order dynamic model.HPGPC showed the molecular weight of GLP were from 1.35×10^3 to 2.26×10^7 Da.FT-IR results suggested β-pyran ring in GLP.SEM showed that GLP was flaky and the surface appeared dry folds.The kinetic model established lays the foundation for the optimization of the continuous phase transition extraction technological conditions and further theoretical study.

关 键 词：灵芝 多糖 连续相变 动力学模型 萃取 

分 类 号：TS201.2[轻工技术与工程—食品科学]