Abstract:

The effects of tempering and fatty acid composition on the compatibility of chocolate fats, i.e., cocoa butter (CB)
blended with fully hydrogenated palm kernel stearin (FHPKS), the hardness of chocolate and chocolate blooming during
storage at 20 亷 for 12 weeks were evaluated. Without tempering, the isosolid phase diagram showed a dilution effect
with increasing proportion of CB. With tempering, an eutectic behavior occurred when the mixtures contained 30%.50%
CB. Tempering and compatibility of chocolate fats had a significant effect on the hardness of chocolate. The hardness was
decreased with increasing CB from 0 to 50%. When the content of CB was higher than 50%, two different trends occurred,
i.e., the hardness of the tempered chocolate increased obviously whereas the hardness of the non-tempered one kept constant.
During storage of chocolate at 20 亷 for three months, it was found that tempering was an important factor affecting
chocolate blooming. All the non-tempered chocolate had bloom within 3-month storage tests, and the degree of bloomingfor
non-tempered chocolate was positively correlated to the CB content. After tempering, 10%.50% CB had less bloom
formation than the non-temper ones whereas the products containing 60%.100% CB kept glossy. The results of DSC and
fatty acid compositions indicated that polymorphic transformation from the unstable to the stable state was the reason for the
bloom of non-tempered chocolate containing 亜 50% CB, and the mechanism for bloom formation of chocolate with .50%
CB may mainly be attributed to the lipid migration due to the incompatibility between CB and FHPKS .

Key words: cocoa butter, fully hydrogenated palm kernel stearin, temper, isosolid diagrams, bloom, hardness