活性炭对玉米朊中黄色素的吸附机理研究  

Adsorption Mechanism of Activated Carbon During Zein Decolorization Process

作　　者：韩及华[1] 吴其飞[1] 徐斌[1] 薛丁萍[1] 

机构地区：[1]江苏大学食品与生物工程学院,镇江212013

出　　处：《中国粮油学报》2016年第10期98-107,共10页Journal of the Chinese Cereals and Oils Association

基　　金：科技部创新基金(11C26213201415);扬州市农业科技攻关(SGG201220049)

摘　　要：为了揭示活性炭脱色玉米朊过程中活性炭对色素和蛋白的吸附机理,本研究首先对活性炭进行扫描电镜、比表面积及孔径分析,在此基础上研究活性炭对色素和蛋白的吸附动力学和热力学。结果表明,活性炭P的吸附能力、比表面和孔隙结构最佳,可作为研究对象;活性炭P对色素和蛋白的吸附均可以用Langmuir模型和Freundlich模型(R^2>0.92)描述;吸附动力学研究表明,活性炭吸附色素和蛋白过程中,伪二级动力学模型(R^2>0.99)占主导地位;吸附热力学研究表明,活性炭吸附色素和蛋白过程中,△G^0<0,△Ha^0>0,S^0△>0,△G^0绝对值随温度升高而增大。活性炭对色素的吸附效果不仅受表面结构和比表面积影响,还与活性炭的微孔或中孔结构有关;活性炭以单层吸附与多层吸附共存的复杂吸附方式吸附黄色素,通过物理和化学复合吸附、膜扩散等共同作用脱除黄色素。In order to explore the adsorption mechanism of activated carbon during zein decolorization process, the microstructure of activated carbons for decolorization was analyzed by scanning electron microscopy （ SEM）, surface area analysis （BET） and pore size distribution analysis. Then, we focused on researching the adsorption isotherm, adsorption kinetics and thermodynamics parameters of decolorization process for activated carbon P （ACP）. The results showed that activated carbon P （ACP） had optimum adsorption capacity, surface area and pore structure. Both Langmuir and Freundlich models fit the adsorption data of pigment and zein on ACP quite reasonably （R^2 〉 0.92）. The adsorption kinetics suggest pseudo - second - order kinetic model was the dominant model all through the total adsorption process （R2 〉 0.99）. Thermodynamics parameters showed that the adsorption of pigment and zein on ACP was spontaneous （ △G^0 〈 0） and endothermal （ △Ha^0 〉 0 ） , and entropy was the driving force （ △S^0 〉 0 ）. We could conclude that the adsorption capacities of activated carbons were affected by not only the surface structure and specific surface area, but also micropore and mesopore structure. The adsorption of pigment on activated carbon was a complex process accompanying with monolayer and muhilayer adsorption and was the result of joint action of physical and chemical composite adsorption, membrane diffusion etc.

关 键 词：玉米朊 脱色 活性炭 动力学 热力学 吸附等温线 

分 类 号：TS201.1[轻工技术与工程—食品科学]