The addition of certain vegetable fats to chocolate is permitted under the Cocoa and Chocolate Products Regulations 2003 up to a maximum level of 5%. Only tropical fats which have similar properties to cocoa butter i.e. cocoa butter equivalents (CBE) are permitted. The addition of these fats standardises the physical properties of the cocoa butter in the chocolate. Other fats, usually hydrogenated fats termed Cocoa Butter Substitutes (CBS) and Cocoa Butter Replacers (CBR) are not permitted under these Regulations.
A method has been previously developed to measure the amount of CBEs accurately in plain chocolate. This project will extend this method to milk chocolate, which has the added analytical complication of containing milk fat as well as cocoa butter. In addition, a protocol to detect the presence of CBSs or CBRs will be developed. This research will be coordinated with parallel wok in the European Commission’s Joint Research Centre in Geel, Belgium.
The research will use stigma-5-ene as a marker for hydrogenated fats, and establish a threshold level to establish absence of hydrogenated fat ingredients. The study will compare using pentadecanoic acid as an alternative marker to measure milk fat than the more commonly used marker – butyric acid. In addition different fat extraction methods will be compared to find which gives the best fat extraction for vegetable fat/milk fat determination.<P>
Results and findings:<BR>A limit of 01mg/kg of stigma-5-ene was established as the threshold for the absence of hydrogenated fats in chocolate. The comparison of methods for milk fat determination reveals that the butyric acid method is better than the proposed alternative. However for the purposes of applying the CBE method, the pentadecanoic acid method is more useful. The results of the investigation of the methods available for the determination of the total fat of chocolate and the extraction techniques shows that Soxhlet method (fat determination involving extraction of fat by controlled re-cycling of a small amount of solvent) gave the best results and that the profile of the triglycerides (chemical form of fat) is not affected by the extraction techniques.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.