Abstract:

Cocoa butter was crystd. in the differential scanning calorimeter in the presence and the absence of sorbitan monostearate at different cooling rates. The solidification and fusion curves were recorded. The cooling rate affects enthalpies and temps. of phase transitions. Very slow cooling causes a significant decrease in crystn. enthalpy, suggesting that fractionation of glycerides occurs under these conditions. In the presence of 5% sorbitan monostearate, cooling and heating curves of cocoa butter are sharper, the solidification point is higher, and the fusion point is slightly lower; further, both crystn. and fusion enthalpies are lower than in pure cocoa butter. The presence of the emulsifier seems mainly to promote fractional crystn. Fusion curves after different periods of isothermal crystn. suggest that higher polymorphic forms differ in chem. compn. from lower ones, and that the presence of sorbitan monostearate affects the fractionation in the fat. [on SciFinder(R)]