Fatty acid tryptamides as shell indicators for cocoa products and as quality parameters for cocoa butter

Abstract.

The methods used to date to determine the shell content in cocoa products are very time-consuming, protracted and not specific enough, meaning that with the development of a new high-performance liquid chromatography (HPLC) method using fluorescence detection, a considerably more specific process is now available. Fatty acid tryptamides can be drawn on as indicator substances for detecting the shell content in cocoa products. The relevant substance species are docosanoyl-2-(3-indolyl)ethylamide (behenic acid tryptamide, BAT) and tetracosanoyl-2-(3-indolyl)ethylamide (lignoceric acid tryptamide, LAT).

To allow conclusions on the average levels of fatty acid tryptamides (FAT) in cocoa products to be drawn, 433 cocoa samples were analysed. The natural tryptamide concentrations in cocoa shells and cocoa nibs or cocoa liquors varied significantly. The average ratio of cocoa shells to cocoa nibs/cocoa liquors is 16:1. As a result of these differences in concentration, the shell content can be determined with a high degree of accuracy via the fatty acid tryptamides in cocoa.

This method also allows conclusions to be drawn on the quality of cocoa butter. The tryptamide concentrations in pressed cocoa butter and in expeller butter respectively vary greatly, so that it is possible through the FAT levels determined to gain an insight into the method of production of cocoa butter.