Effects of Cocoa Butter Origin, Tempering Procedure, and Structure on Oil Migration Kinetics

The effects of cocoa butter (CB) origin, tempering procedure, and structure on oil migration kinetics were studied using a flat bed scanner followed by image processing and analysis. The migration rate (OMR) and migration distance (I-10) of stained oil were determined in tempered and nontempered CBs. Tempered matrices had 10 to 50 times lower OMRs than nontempered CBs. In addition, the lag phase observed before significant oil migration was also significantly longer in tempered CBs (12 days vs 2 days in nontempered butters). Moreover, cocoa butter origin had a strong effect on OMR. Brazilian and Nigerian CBs had the highest OMR in both tempered and nontempered samples. Malaysian CB had the third highest OMR, but this effect was only significant in untempered samples. Finally, the lowest OMRs were found in Chinese, Ecuadorian, and Ivorian cocoa butters. The amount of oleic acid and triunsaturated triglycerides (UUU) was strongly correlated to OMR (the higher the UUU concentration, the lower the resistance to oil migration). However, the relationships between the permeability coefficients and structural factors (squared averaged particle size and crystalline domain size) suggest that the micro- and nanostructure of the material also plays a significant role in the oil migration process.