Abstract
Fat boom stability of cocoa butter to which sucrose fatty acid ester, POS-135, and polyglycerol fatty acid esters, 10G9POS and 10G12POS had been added was studied by scanning electron microscopy (SEM) and X-ray diffraction measurement (XRD) so as to clarify the mechanism for anti-bloom effects of emulsifiers. Fatty acids compositions of the emulsifiers were similar to that of cocoa butter, all involving palmitic, stearic and oleic acids. Cocoa butter was crystallized in form V by seeding β2 form crystals of 1,3-behenoyl-2-oleoyl glycerin and transformation to form VI was examined by tempering for 432 hours through 20°C (12 hours) and 30°C (12 hours) thermocycle.
In the case of cocoa butter without emulsifiers, XRD showed cocoa butter to be completely transformed from form V to VI after a 120 hour thermocycle treatment before fat bloom could be visually observed. Bloom was observed after a 292 hour thermocycle.
It was observed that POS-135 retarded the transformation to cocoa better and fat bloom formation most enhancedly in comparison with 10G9POS and 10G12POS. This mean that the effect of hydrophilic unit structure of sucrose of POS-135 is important for the inhibition the fat bloom formation.
