Pigments incorporation process

Aggregates formed by primary particles and agglomerates have to be broken down by a dispersion process. An adequate dispersion of pigments is a basic requirement of any incorporation process [71. 

Ease of Incorporation Evaluating pigment incorporation should be consistent with the methods of processing used in manufacture. A usefiil laboratory test involves banding a standard white compound on a two-roll mill. The pigment or dispersion to be tested is added and milled for 3 minutes. The batch is then removed, allowed to cool to room temperature, placed back on the mill and examined for color streaks and other evidence of unincorporated pigment. With compounds that do not mill well, the color dispersion should be added using a laboratory extrader under conditions comparable to plant operation. 

Rotomolding parts with aluminum pigments has been a challenge, as this process provides limited aesthetic effects. Rotomolding compounds made by fine micro-pelletization provided a good method of aluminum pigment incorporation. Our research was to determine the benefits and limitations of this manufacturing method. 

When the problem is to disrupt Ughtly bonded clusters or agglomerates, a new aspect of fine grinding enters. This may be iUustrated by the breakdown of pigments to incorporate them in liquid vehicles in the making of paints, and the disruption of biological cells to release soluble produces. Purees, food pastes, pulps, and the like are processed by this type of mill. Dispersion is also associated with the formation of emulsions which are basically two-fluid systems. Syrups, sauces, milk, ointments, creams, lotions, and asphalt and water-paint emulsions are in this categoiy. 

The bioaccessibility of a compound can be defined as the result of complex processes occurring in the lumen of the gut to transfer the compound from a non-digested form into a potentially absorbable form. For carotenoids, these different processes include the disruption of the food matrix, the disruption of molecular linkage, the uptake in lipid droplets, and finally the formation and uptake in micelles. Thus, the bioaccessibility of carotenoids and other lipophilic pigments from foods can be characterized by the efficiency of their incorporation into the micellar fraction in the gut. The fate of a compound from its presence in food to its absorbable form is affected by many factors that must be known in order to understand and predict the efficiency of a compound s bioaccessibility and bioavailability from a certain meal. ... 

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