Effect of fermentation parameters on the antioxidant activity of Ecuadorian cocoa (Theobroma cacao L.)

Cocoa (Theobroma cacao L.), indigenous to the tropical forests of the Americas, is renowned not only as the primary raw material for chocolate and its derivatives (cocoa liquor and butter) but also as a rich source of phytonutrients with beneficial health effects. Current research has elucidated that within the post-harvest process, fermentation stands as the critical stage for the formation of the principal biochemical quality markers in cocoa, known as polyphenols. These compounds contribute to the bitterness and astringency that constitute the complex flavor profile of chocolate; however, their excessive presence can be organoleptically undesirable. A high phenolic content (>10%) is associated with insufficient fermentation and certain varieties of ordinary cocoa, thereby serving as a discriminatory parameter between fine-flavor cocoa (Nacional) and bulk cocoa (CCN-51). Beyond their technological significance, these components have garnered substantial scientific interest, as polyphenol consumption is associated with potential protective effects against the development of non-communicable chronic diseases (including diabetes, cancer, and atherosclerosis), attributable to their potent antioxidant properties. In this context, the objective of this study was to evaluate the impact of fermentation time on the antioxidant capacity (AC) and total polyphenol content (TPC) in the principal Ecuadorian cocoa varieties (i.e., CCN-51 clone and Nacional). Pilot-scale fermentation experiments demonstrated significant variations in antioxidant capacity (CCN-51 clone: 785.61 to 1852.78 and Nacional: 564.32 to 1428.60 µmol TE/g) and total polyphenol content (CCN-51 clone: 52.92 to 162.82; Nacional: 40.55 to 157.50 mg gallic acid/g). Both parameters decreased markedly throughout the process, with the CCN-51 clone exhibiting greater retention.