Effect Of Fermentation On NIB Acidity, Fermentation Index And Residual Anthocyanin Content In Dry Cocoa Beans

  • D. K. Adzaho
  • Y. Opoku-Asiama
  • Y. Adu-Ampomah
  • J. F. Takrama


In 2003/2004 main crop cocoa seasons, chocolate manufacturers reported of unusually high levels of purple beans in cocoa from Ghana. Purple beans, according to the chocolate manufacturers, produced cocoa liquor that have less flavour and high acidity. These reports coming soon after the recently introduced Cocoa Diseases and Pests Control (CODAPEC) and Cocoa Hi-Tech. programmes in Ghana, raised a lot of concern in the cocoa industry. This study examined anthocyanins levels of different categories of purple colour in dry cocoa beans. A Complete Randomised Design (CRD) was used with the principal factors evaluated as Fermentation Index, nib pH and anthocyanins contents of fermented dry cocoa beans. The study indicated that cocoa beans of a minimum Fermentation Index of one within fermentation period of five and six days was deemed well fermented. Again, cocoa beans of residual anthocyanins of 2.0 mg kg-1 and of a pH 5.4 to 5.5 were of good quality. The study also showed that dry cocoa beans with brown colour had residual anthocyanins of 1.5 mg kg-1, that for partly brown/partly purple was 1.80 mg kg-1; in the pale purple beans it was 2.07 mg kg-1. The deep purple beans had residual anthocyanins of 2.33 mg kg-1. These findings suggest that pale and partly brown/partly purple beans were as good as the acceptable cocoa beans of brown colour.