15 - Milk Fat and Cocoa Butter

Abstract

The mixture of milk fat and cocoa butter provides challenges for controlling lipid interactions to give consistent product quality. From phase behavior to crystallization kinetics, understanding the interactions between milk fat and cocoa butter is critical for controlling the quality characteristics and shelf life of milk chocolate. The addition of milk fat to chocolate creates a complex mixture of TAGs whose crystallization behavior is quite complex. There are several notable changes in chocolate due to the effects of milk fat addition. The softening effect from adding milk fat to cocoa butter is easily explained through phase behavior. Milk fat also has an inhibitory effect on cocoa butter crystallization, which means that chocolate containing milk fat must be tempered at different conditions. Specifically, milk chocolate is tempered at slightly lower temperatures than dark chocolate to offset the inhibitory effects and allow more rapid cocoa butter crystallization. The milk fat is known as a bloom inhibitor, most likely through its effect on slowing the polymorphic transformation of cocoa butter to the most stable polymorph, β-VI.