Precursors of chocolate aroma – flavour profile comparisons of traditionally fermented cocoa and cocoa beans from fermentation-like incubation by means of HS-SPME-GC-MS-O

Abstract

Aroma precursors developed during fermentation are of indispensable importance for choc-olate aroma formation. Generation of a standardised high-quality aroma profile of cocoa would be beneficial for producer and processing industry. Fermentation-like incubation could be an option for realization to obtain a standardised quality. In the present study a HS-SPME-GC-MS method with olfactometry was applied to compare the flavour profile of cocoa beans from traditional fermentation and of fermentation-like in-cubation. Additionally, the flavour profile development over time of fermentation-like incu-bation was investigated. In total 34 odour-active volatile compounds were identified in this study for traditionally fer-mented cocoa and for cocoa from fermentation-like incubation. Both cocoas of traditional fermentation and fermentation-like incubation are characterised by the same important odour notes green, fruity, cocoa/caramel and acid. Also, a difference in spectrum of com-ponents of cocoa beans from traditional fermentation and fermentation-like incubation was observed. Cocoa beans from traditional fermentation developed more components per-ceived as vanilla odours and one component perceived as cheesy. Cocoa beans from fer-mentation-like incubation developed more components which have cocoa/nutty, soapy, al-coholic odour notes and one component smelling musty, putrid. The investigation of odour-active substances over the time of fermentation-like incubation showed that this form of fermentation also yields fruity and flowery notes typical for fine flavour cocoa as well as cocoa and acid notes. The aroma profile of cocoa from fermentation-like incubation seems due to lack of several vanilla notes less complex. However, aroma-profile of cocoa beans from fermentation-like incubation shows a higher stability as no indication of overfermentation was observed. Both characteristics minor complexity and better stability, could be explained by the absence of microorganisms during fermentation-like incubation.