STUDIES OF BLOOM FORMATION USING X-RAY-DIFFRACTION FROM CHOCOLATES AFTER LONG-TERM STORAGE

This note describes experiments and results obained using X-ray powder diffraction, Differential Scanning Calorimetry and Nuclear Magnetic R esonance techniques to study the polymorphic condition of cocoa butter in samples of chocolate which have been carefully stored for long per iods of time. The results show that bloom formation is accompanied by the presence of a different polymorphic form (VI) to the bloom-free ca se (form V). Also evident is an enhanced resistance to polymorphic tra nsition at a reduced temperature of storage, 18-degrees-C, or the addi tion of a small amount of butter fat to the chocolate. These effects a re apparent after more than three years on storage.