Global decline in cocoa butter quality, coupled with growing demand for high quality cocoa butter mean that more robust but flexible refining technologies are required, say researchers.
The study – published in the Journal of Food Engineering – investigated the impact of the cocoa butter refining process on milk chocolate quality, finding that a ‘flexible’ process that involves the option of pre-treatment with silica and the ability to refine at varying temperatures could help to boost the quality of milk chocolate products.
The team, led by Nathalie De Clercq of Ghent University, Belgium, subjected a crude cocoa butter to a steam refining process at different temperatures, in addition to testing the effects of using silica pre-treatment.
Because cocoa butter forms the continuous phase of chocolate, it has a major influence on the quality of the final product, said the researchers.
“Therefore, it is crucial that the cocoa butter has an optimal quality,” they revealed. “Many processing steps precede the final cocoa butter pressing but it may still contain undesired components sometimes making it necessary to refine the product.
The team found that high temperatures used to refine the cocoa butter reduced the levels of free fatty acids – which in turn influenced the crystallisation process.
“By tuning the refining conditions (pre-treatment or no pre-treatment, temperature of the refining process) the cocoa butter properties could be manipulated to suit the desired chocolate properties,” they said.
“Reduction of free fatty acids positively influenced the crystallization kinetics and the formation of the crystal network, resulting in differences on a macroscopic scale.”