Dynamic crystallization of dark chocolate as affected by temperature and lipid additives

The dynamic crystallization was studied in a lab-scale Scraped Surface Heat Exchanger by following variations with time of torque applied during different isotherms between 24.9 degrees C and 31.0 degrees C. Crystallization was in two steps for T 26.2 degrees C but it was in one step at T<26.2 degrees C. The first step corresponded to crystallization of about 1% solid fat and was related to that of saturated triacylglycerols (SSS) which segregated from other cocoa butter triacylglycerols (TAGs) because of their low solubility in TAGs. The second step, an abrupt increase of apparent viscosity, leading to complete crystallization was attributed mainly to the monounsaturated TAGs in the beta form. Different amounts of tristearin increased the apparent viscosity and reduced the latent time preceding the first step, but did not influence the main crystallization. Stearic acid and distearin additions also influenced chocolate crystallization.