Evaluation of Milk Fat Fractionation and Modification Techniques for Creating Cocoa Butter Replacers

Abstract

The utilization of milk fat fractions or interesterified milk fat fractions in chocolate confectionery was examined. Anhydrous milk fat was fractionated by two methods: multiple step melt crystallization; and supercritical carbon dioxide extraction. The middle- and high-melting fractions were then interesterified using an immobilized lipase under conditions of CO 2 at atmospheric pressure or CO 2 at supercritical pressures. Milk fat and milk fat fractions were used to prepare mixtures with cocoa butter which were analysed for solid fat content using nuclear magnetic resonance. Isosolid diagrams were prepared from solid fat data to evaluate interactions between milk fat and cocoa butter. Experimental milk chocolates with 10% or 20% of the cocoa butter replaced by milk fat fraction were evaluated. These chocolates also contained intact milk fat added as whole milk powder during conching. Evaluation of cocoa butter/milk fat mixtures indicated that the high-melting fraction produced by melt crystallization was more compatible with cocoa butter than anhydrous milk fat, particularly after interesterification under atmospheric or supercritical conditions. No other fraction, native or modified, displayed significantly increased compatibility. Evaluation of experimental milk chocolates demonstrated that chocolates prepared with modified high-melting fractions replacing 10% of the cocoa butter were significantly harder than chocolates containing 10% of any other milk fat fraction, native or modified. However, these chocolates were still significantly softer than the control chocolate. More potential may exist for using milk fat fractions in dark chocolate than for milk chocolate, which already contains milk fat.