An extensive series of layered minerals including montmorillonite was studied to determine if the fundamental physicochemical properties responsible for pigment adsorption could be identified. Samples were subjected to a uniform preparation regimen to eliminate such secondary effects as particle size, moisture content, level of activation and degree of washing. By doing so, it has been possible to show that both carotene and chlorophyll adsorptions can be described by a rather simple model that employs both surface acidity and pore volume as key variables. Further, it was found that this model provides an adequate fit to the actual data only when specific regions for these variables are considered (i.e., concentration of sites of strong surface acidity, not just total surface acidity; pore volume in region 50\s‐200 Å, not just total pore volume).

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The adsorption of model fatty acids (hepatnoic, oleic), using spiked vegetable oils, was studied using different kinds of zeolites (A‐zeolite, X, Y‐zeolites, mordenite), Y‐zeolite exchanged with different cations (alkali, alkaline earth, transition metal ions), and with bleaching clay/zeolite blends. The adsorption process was shown to be governed by the molecular sieving properties of the zeolites involved as well as the electrostatic field strengths of the exchange cations. Facile interparticle diffusion of cations between clay and zeolite particles in the blends was verified by electron microprobe analysis and shown to cause unexpected results with respect to bleaching and fatty acid removal.