Structural and color changes in the Criollo Cocoa beans during assisted fermentation

Abstract

One of the key determinants of the sensory quality of cocoa by-products is the inclusion of fermentation as a critical unit operation in the production process. During fermentation, significant physical, chemical, biochemical, and structural changes occur, all of which are essential for the development of sensory precursors in cocoa and its derivatives. While the chemical and biochemical changes during fermentation are well documented in the literature, relatively little attention has been given to the structural changes occurring within the beans throughout this process. The aim of this study was to produce a photographic record of the structural changes in Criollo cocoa beans over seven days of fermentation, assisted by the addition of Acetic Acid Bacteria (AAB). In addition to bean swelling, darkening of the external surface through oxidation, and loss of the mucilaginous layer, Criollo cacao exhibits an ivory internal coloration throughout fermentation due to the absence or low concentration of anthocyanins. This characteristic coloration results in a light hue upon sun-drying (“light break”), as observed in the cutting test, giving Criollo cacao a unique identity that distinguishes it from other types such as Hybridized and Forastero, which display a deep brown color after sun-drying. The findings of this study provide a foundation for future research on aroma formation in cocoa during fermentation.