Aroma active compounds of several kinds of chocolate

This diploma thesis is focused on the problem of volatile aroma active compounds in chocolate, directly connected with the formation of chocolate aroma. Organoleptic properties of chocolate (aroma and taste) are the most important for evaluating by consumers. In this work four types of plain chocolate: Figaro Sweet Passion 70 % cacao, Figaro plain chocolate, Figaro for cooking and KAUMY chocolate glaze were tested. SPME method (fiber CAR/PDMS 85µm) in conjunction with gas chromatography was chosen for their analysis. Solid phase micro-extraction (SPME) is simple, sensitive, reproducible, rapid and low-cost method for evaluation of key odorant compounds found in cocoa and chocolate products. Using SPME-GC method total 56 aromatic compounds: 14 acids, 9 aldehydes, 8 ketones, 17 alcohols, 7 esters and 1 nitrogen compound were identified and quantified. Taste and aroma are the most important for evaluating of chocolate by consumer. Taste and aroma should be aromatic, pleasant and after used raw material. The single organoleptic properties (appearance, colour, taste, aroma and texture) were observed by sensory analysis using scale and also aroma and taste profiles of samples were created. The assessors were students and staffs faculty of chemistry BUT. The high content of alcohols (methanol, ethanol, propanol, butan-2,3-diol) and fatty acids was found in all types of chocolate , these compounds are probably important components of chocolate aroma. Some detected aromatic compounds doesn´t contribute positively to typical chocolate aroma. Unpleasant odour of these compounds often influences total flavour of chocolate, which was also proved by sensory evaluating