To investigate the effects of particulates on fat bloom in chocolate, model systems were formulated with 50% nonfat particles and 50% cocoa butter on a mass basis, where cocoa powder was gradually replaced by sugar particles (sucrose, maltitol, corn syrup solids [CSS], and polydextrose [PD]). Bloom extents were investigated in three ways: the change in whiteness index (Delta WI), white area percentage, and visual bloom level. All three bloom evaluation methods showed similar trends, although the methods were more sensitive under different conditions. Bloom extents in sucrose model systems were the highest compared to the other three sugar types, whether crystalline or amorphous. Increasing sucrose crystal levels significantly promoted bloom, whether with or without 0.5% lecithin. Adding 0.5% lecithin significantly reduced bloom extents in all model systems except for the system with CSS. The effects of sugars and lecithin might be due to the difference in the interactions between sugar particles, cocoa powder, and lecithin in the chocolate matrix, as supported by the contact angle and tensiometry results.
