Tempering method for chocolate containing milk-fat fractions

Anhydrous milk fat (AMF) was fractionated by a two-stage dry fractionation process to produce three fractions-high-(HMF), middle-(MMF), and low-melting (LMF). The effect of replacing 12.2-40% by weight of cocoa butter with these fractions on the tempering profile of milk chocolate was studied. Degree of temper was evaluated by differential scanning calorimetry, and expressed as the ratio of enthalpies of melting for higher-stability polymorphs to those of lesser stability. The degree of temper was dependent on the crystallization time and temperature, and the type and quantity of milk-fat fraction in the formulation. Chocolates containing AMF or its fractions in concentrations of up to 20 wt% (total fat basis) were tempered after a conventional thermocycling tempering process (50 degrees C/30 min, 27.7 degrees C/4 min, 31 degrees C/2 min) to obtain products with good contraction and mold release properties. For those milk chocolate formulations that did not temper by the conventional method and resulted in poor contraction and mold release, a new tempering protocol was developed. Lower crystallization temperatures and/or longer holding times were required at concentrations of AMF, MMF, or LMF above 20%. Chocolate containing HMF required slightly higher crystallization temperatures because of high viscosity. Chocolates containing up to 35% HMF and up to 40% of the total weight of fat in the chocolate of AMF, MMF, and LMF were successfully tempered by adjusting crystallization time and temperature.