INCORPORATION OF MILK-FAT AND MILK-FAT FRACTIONS INTO COMPOUND COATINGS MADE FROM PALM KERNEL OIL

The potential of incorporating anhydrous milk fat and milk fat fractio ns into compound coatings based on palm kernel oil was investigated. F ractionation of milk fat by melt crystallization was utilized to prepa re five fractions with different melting profiles. The anhydrous milk fat and milk fat fractions were added at 5, 10, and 15% of the fat pha se in compound coatings made with palm kernel oil. Fats were analyzed for fatty acid and triacylglycerol profiles, solid fat content, therma l profile, and melting point. Coatings that were made with the additio n of anhydrous milk fat or milk fat fractions were generally softer th an the control coating, although hardness depended on the melting poin t of the added milk fat fraction. Coatings made with fractionated, hyd rogenated palm kernel oil developed fat bloom (the whitish haze that f orms on a chocolate surface) faster than coatings made with fractionat ed palm kernel oil during storage at ambient conditions. As hardness i ncreased, induction time for bloom formation and time to full bloom de creased. Binary mixtures of palm kernel oil and milk fat exhibited dil uent mixing effects and contained only beta' polymorph crystals.