Activated carbon has different physical and chemical properties due to different raw materials and manufacturing methods, which makes its adsorption capacity different. Generally, when the adsorbent is low-molecular, coconut shell activated carbon with micropores is more suitable, and the activated carbon of the coal system is more suitable for the solution of adsorbent materials from low-molecular to large-molecule.

The larger the specific surface area of activated carbon, the stronger the decolorization ability. However, in terms of chemical adsorption, it is not very accurate to select activated carbon only based on the general performance provided by activated carbon manufacturers, such as methylene blue adsorption capacity, iodine value, phenol value adsorption capacity and specific surface area. In particular, the functional groups of organic impurities in the syrup are mostly hydroxyl (phenol type) and carboxyl groups, which easily increase the polarity of the activated carbon surface. The surface of the activated carbon may be positively or negatively charged, thereby chemically combining with the organic impurities in the syrup. In this case, the appropriate activated carbon should be selected through the decolorization test of the actual syrup.