Cocoa liquor is the product obtained from the beans of Theobroma cacao L. and together with cocoa butter, sugar and soy lecithin, it is the major ingredient of chocolate. There are four main varieties of T. cacao, including the Forastero variety, considered as “bulk”, and the Nacional variety, considered a “fine-flavor” cocoa.
In this research, both cocoa liquor and chocolate, produced from a blend of West African (“bulk”) cocoa beans and cocoa beans originating from Ecuador (Nacional variety, “fine-flavor”), were thoroughly investigated with regard to their composition. The nutritional composition was determined to obtain information about the levels of the primary metabolites, while secondary metabolites were investigated by means of GC-MS (gas chromatography – mass spectrometry) and UPLC-HRMS (ultra performance liquid chromatography – high resolution MS), for volatile and non-volatile compounds, respectively.
A wide range of compounds were analyzed: almost 70 volatile compounds were identified and semi-quantitatively determined by GC-MS, while more than 40 compounds were (tentatively) identified by UPLC-HRMS, of which 15 were quantified. Interestingly, various volatiles, which contribute significantly to the final flavor, were more abundant in the West African cocoa liquor and chocolate, while with regard to the non-volatile secondary metabolites, the Ecuadorian samples were richer, when it comes to most of the quantified substances. Additionally, principal component analysis (PCA) of the datasets confirmed that the four samples can be clearly distinguished based on their chemical profile. Certain specific constituents, including alcohols, pyrazines, amino acids and biogenic amines were found to be highly influential in causing this clear differentiation between the samples.
