A method for non-destructive determination of cocoa bean fermentation levels based on terahertz hyperspectral imaging

Fermentation of cocoa is a key process to obtain aromatic chocolate products from raw cocoa beans. Hitherto, the levels of fermentation in cocoa are determined using destructive techniques, for example by a cut-test to manually observe the colour inside the beans, or by quantifying ammonia nitrogen (NH₃) in the cocoa powder. In this paper, we present the use of Terahertz hyperspectral imaging as a new way to non-destructively analyse and detect fermented cocoa beans. The study analysed two sets of twenty-two cocoa bean samples with different levels of fermentation from two producers in Brazil. A correlation between fermentation conditions and the outcome results of their THz measurements was observed.