Analysis of cumulative oxygen uptake in cocoa beans (Theobroma cacao L.) fermentation using a packed bed reactor

The research aims to determine cumulative oxygen uptake in cocoa beans fermentation using packed bed reactor. Observed variables were including: length times of cocoa fruit ripening before fermentation (X₁) i.e., 1; 5; 9 days, aeration rate (X₂) i.e. 0.2; 0.3; 0.4 liters/minute, and aeration mode (X₃) is intermittent 1; intermittent 2; continuous. The response surface methodology was used to figure out and to describe the relationship between cumulative oxygen uptake to the variables. The research results showed that the highest oxygen consumption occurred on day 2 and day 3 of the fermentation process, where the average peak oxygen demand occurred at the hour 25-72 fermentation, then continue to decline until end of the fermentation process (at fermentation time to 120 hours). The value of cumulative oxygen uptake during the fermentation process using a response surface methodology was obtained at 7.291 – 25.350 g O₂/kg vs on various treatments. The results of response surface methodology also showed that the highest oxygen consumption during the cocoa beans fermentation was obtained on cocoa fruit ripening of 1-3 days, aeration rate of 0.3-0.4 litres/minute and continuous aeration mode. While the lowest oxygen consumption was obtained on cocoa beans ripening of 1 day, aeration rate of 0.2 to 0.3 litres/minute and aeration mode of intermittent 1.