The Science of Chocolate: Losing The Fat, Keeping The Snap

The satisfying snap of chocolate is a big part of its appeal 

If chocolate was one of our ‘five a day’, many of us would have no trouble reaching the target. Alas, it is not, and in reality it is a food which contains a lot of fat, along with sugar and cocoa.

The fat constituent can be up to 40% in a basic dark chocolate.

Fat and its ability to form crystals is an important part of many foods as it can crystallize and influence taste, consistency and appearance.

Manufacturers are keen to make chocolate healthier, and less calorific, but they must do this without losing its attractive qualities, such as: its taste, the fact that it is solid at room temperature, yet melts at body temperature and has that satisfying snap when it breaks. One way to make chocolate healthier is to try to reduce the fat content: this is called reformulation.   

Removing fat can introduce processing problems, the reduction in fat can make the chocolate more viscous with the result that the current methods of production are no longer suitable or may be inhibited. To combat this limonene can be added to make it softer. Limonene oil is an orange/citrus food flavouring that can be mixed with the chocolate to dilute the fat so you need less of it, to get the same benefits.

The scientists at the University of Nottingham and Loughborough University have used a Diaplan Leitz microscope, Digital Pixelink PL-A662 camera and our Linksys32 software to investigate if the limonene had an affect on the formulation, shape and size of fat crystals. 

Chocolate samples, one with the limonene added and one without it were observed for microstructure changes over a period of 4 weeks. The scientists have managed to take some great images of the crystalised fat observed on the sample. 

A photo of a chocolate fat crystal

To find out more about this research please see the paper

The Effect of Limonene on the Crystallization of Cocoa Butter

Journal of the American Oil Chemists' Society

March 2012, Volume 89, Issue 3, pp 437-445

Joydeep Ray, William MacNaughtan, Peng Siong Chong, Josélio Vieira, Bettina Wolf

By Caroline Feltham