Analysis of pH and Color of Fermented Cocoa (Theobroma cacao L) Beans using Response Surface Methodology

Cocoa (Theobroma cacao L) is a tropical plant that is widely used as a basic ingredient in chocolate production. The quality and taste of chocolate are greatly influenced by the stages and processes of post-harvest handling. Some post-harvest processes that are recognized for improving cocoa quality are pod storage, fermentation, and drying. The quality of cocoa beans can be known based on several physical and chemical parameters, including the color and pH of cocoa beans. This study aimed to analyze the effect of pod storage before fermentation (X-1), aeration rate (X-2) and aeration mode (X-3) during the fermentation process on pH (Y-1), chroma (Y-2), and hue (Y-3) of cocoa beans after fermentation and drying. Response surface methodology (RSM) was used to observe the relationships among the X-1, X-2, X-3 variables and the Y-1, Y-2, and Y-3 of dried cocoa beans, with the following treatments: X-1 = 1; 5; 9 days, X-2 = 0.2; 0.3; 0.4 liters/minute, X-3 = intermittent 1; intermittent 2; and continue. The pH, chroma and hue of dried cocoa beans were: 4.873-6.517, 9.99-32.20, and 28.85-71.53, respectively. Furthermore, analysis of variance showed that pod storage before fermentation process significantly affected the hue but did not significantly affect the pH and chroma. The aeration rate had a significant effect on the pH and hue but did not have a significant effect on the chroma, while the aeration mode had no significant effect on the pH, chroma, and hue of dried cocoa beans.