To clarify the tempering mechanism in solid-fats products, we measured solid content, average size and number of particles by the permeability method developed by us. In this study, we used margarine, shortening and standard sample before and after tempering treatment. Also, the microscopic structures of fats products were observed with a scanning electron microscope. The following results were obtained.
(1) The solid particles in the fats before tempering were agglomerates of fine particles and fine particles dispersed in a certain temperature range, resulting in rapid decrease in average size of particles and increase in solid particle number.
(2) Tempering caused marked changes in size and number of solid particles in solid-fats products, and these changes corresponded well to those of fats before tempering at certain temperature, as mentioned in (1).
(3) The dispersion of constituent fine particles in agglomerates induced by tempering was caused by the change of fat crystals to more stable polymorphism.