活性炭微观结构对玉米朊脱色效果的影响

为研究国内外活性炭在玉米朊脱色过程中吸附色素特性的差异，以玉米朊的乙醇萃取溶液和商业玉米朊 产品乙醇复溶溶液为研究对象，分别采用国产活性炭（ACP）和进口活性炭（ACD）对比研究其对玉米朊的脱色效 果，并对活性炭的微观结构进行表征。静态吸附实验结果表明，活性炭对玉米朊复溶溶液和萃取液的脱色效果没有 明显差异；ACP对玉米朊溶液中色素的吸附率（77.31%）略高于ACD（67.27%）。扫描电子显微镜分析表明，ACP 结构向内延伸而ACD表面凹陷孔结构不明显；比表面积和孔隙结构分析表明，ACP的比表面积（1 438.082 m2/g） 和总孔容积（1.310 cm3/g）大于ACD（779.809 m2/g、0.626 cm3/g），且ACP具有更多的微孔和中孔结构。ACD表 面含有较多的羧酸和内酯类官能团，可与色素分子中的羟基结合，从而有效增强活性炭的化学吸附效果。ACD粒 径分布更加集中，有利于脱色后的固-液分离。综合以上因素考虑，ACD更适合用于黄色玉米朊的脱色处理。

Effect of Microstructure of Activated Carbon on Decolorization of Zein

In order to understand the difference between domestic activated carbon (ACP) and foreign activated carbon (ACD) in the decolorization efficiency of zein, the decolorization efficiency and microstructure of ACP and ACD were compared. The results showed that there was no significant difference between the decolorization efficiencies of zein solution and extract, but the pigment adsorption rate of ACP (77.31%) was higher than that of ACD (67.27%). Furthermore, scanning electron microscopic analysis showed that the structure of ACP was extended inwards while the structure of ACD was less porous. Then, specific surface analysis and pore size analysis showed that the specific surface area and total pore volume of ACP (1 438.082 m2/g, 1.310 cm3/g) were bigger than those of ACD (779.809 m2/g, 0.626 cm3/g) because there were more micropores and mesopores in the structure of ACP. Meanwhile, the surface of ACD showed more carboxylic acid and lactone functional groups, which could enhance the chemical adsorption of activated carbons effectively when bound to the hydroxyl groups in the pigment molecules. Simultaneously, ACD was more homogeneous in particle size, which was beneficial to the solid-liquid separation after decolorization. Taken together, ACD is more suitable for zein decolorization.