Influence of sucrose substitutes and agglomeration on volatile compounds in powdered cocoa beverages.

Volatile aromatic substances are the main factors contributing to the acceptability of cocoa products. The beneficial effect of fat-free ingredients of cocoa beans on human health has been scientifically proven. This encourages the consumption of cocoa products as well as further research on improving their processing technology. The aim of this study was to analyse changes in the composition of volatile compounds and their impact on the sensory characteristics of an agglomerated cocoa powder mixture with modified composition for the raw material. The basic mixture was composed of 20% cocoa and 80% sucrose. Changes in mixture composition involved partial or total replacement of sucrose with maltodextrin or a mixture of glucose and fructose. Mixing and agglomeration were carried out in a fluid bed agglomerator. The analysis of volatile compounds was carried out using a gas chromatograph coupled with mass spectrometer, and 1,2-dichlorobenzene was used as an internal standard. The analysis showed the presence of over 70 various chemical compounds. Such volatile compounds as acetic acid, 2,3-butanediol, nonanal, and pentanoic acid, were found in almost all tested products. The highest content of acetic acid was determined in cocoa powder. In the case of the investigated cocoa beverages, the raw material composition and agglomeration affected their volatile compounds content. The analyses demonstrated a reduction in the content of volatile compounds caused by agglomeration.