油橄榄果渣水不溶性膳食纤维结构表征及体外吸附性能研究

Structural characterization and in-vitro adsorption capacity of olive pomace insoluble dietary fiber

以油橄榄脱脂果渣为原料,采用碱法制备油橄榄果渣水不溶性膳食纤维(Insoluble dietary fiber,IDF),并用红外光谱和X射线衍射等方法对其表征,并测定分析其体外吸附NO-2和重金属Pb^(2+)、Cu^(2+)、Cd^(2+)的功能特性。结果表明:油橄榄果渣IDF中水不溶性膳食纤维含量为90.09%,其主要由纤维素、半纤维素和木质素组成;红外光谱图显示油橄榄果渣IDF具有糖类和木质素的特征吸收峰;X射线衍射图显示油橄榄果渣IDF呈纤维素I晶型,其结晶度为47.94%;在体外模拟胃环境(pH2)下,油橄榄果渣IDF对NO_2^-的吸附在240 min时达到平衡,平衡吸附量为826μg/g;在体外模拟肠道环境(pH7)下,油橄榄果渣IDF对Pb^(2+)、Cu^(2+)、Cd^(2+)的平衡吸附量分别为418.7、686.6、849.5μg/g,IDF在肠道环境下对Pb^(2+)、Cu^(2+)、Cd^(2+)的吸附能力均优于胃环境。IDF对Pb^(2+)、Cu^(2+)、Cd^(2+)的吸附过程符合准二级动力学方程。

Olive pomaee insoluble dietary fiber（IDF） was prepared by alkaline method with defatted olive pomaee.In addition to its chemical composition and structure characterized by IR and X-ray diffraction ,the effect of olive pomace IDF on the in vitro adsorption capacity of NO2^-, Pb^2＋ , Cu^2＋ , Cd^2＋ was studied.These results showed that the IDF content in olive pomace IDF reached 90.09% ,which was mainly comprised by cellulose, hemicellulose and lignin.The result of IR showed that olive pomace IDF appeared characteristics absorption peaks of sugars and lignin. The result of X-ray diffraction indicated that IDF had cellulose I crystal structure, and its crystallinity achieved 47.94% .The quantities of equilibrated adsorption to NO2^- using IDF under the simulated gastric condition（pH2） was attained 826 μg/g at 240 min.The adsorption capacity of IDF tot Pb^2＋ , Cu^2＋ , Cd^2＋ under the simulated intestine condition （pH7）was far stronger than that in the gastric. The equilibrated adsorption quantities for Pb^2 ＋ , Cu^2＋ , Cd^2 ＋ in simulated intestine condition could reach 418.7,686.6,849.5μg/g, respectively.Besides, the pseudo-second-order kinetics equations were exactly fit for those adsorption processes of IDF for Pb^2＋ , Cu^2＋ ,Cd^2＋.