Improved analysis of theobromine and caffeine in chocolate food products formulated with cocoa powder

The amount of methylxanthines (i.e. caffeine, theobromine) in food products continues to be of interest to the public. To provide such data, an improved analytical method for their determination in cocoa-based food products was developed. An aqueous extraction followed by analysis using the method of known additions was found to give a higher degree of accuracy and precision in comparison with the method accepted by the Association of Official Analytical Chemists International. This improved analytical method will allow for the collection of reliable methylxanthine concentration data that can be used to update food composition databases as well as by consumers and health care professionals. (C) 2001 Elsevier Science Ltd. All rights reserved.