Effect of antibloom fat migration from a nut oil filling on the polymorphic transformation of cocoa butter.

In confectionery products, loss in texture contrast between chocolate and filling and the appearance of fat bloom on the surface of the chocolate can be caused by fat migration. Bloom is often linked to the transformation of the cocoa butter betaV polymorph into betaVI. A previous study showed that small additions (1%) of nut oil can have a significant impact on the rate of transformation and that migration of nut oil from a filling would increase polymorphic transformation of cocoa butter. In the present study, antibloom fat was added to the filling in a model system. The antibloom fat migrated with the nut oil and inhibited the transformation of cocoa butter from the betaV polymorph into betaVI. Despite experiencing migration of greater amounts of nut oil, cocoa butter closest to the filling transformed more slowly than that farther away (i.e., the reverse of the situation in the absence of antibloom fat).