Cocoa pod shells are the agro waste generated causing problem during the disposal. In the present study, possibility of utilizing the cocoa pod shells to release the reducing sugars has been ...explored. Hydrochloric acid hydrolysis assisted with autoclave was adopted to obtain reducing sugars. The one parameter at a time approach was implimented to screen the significant parameters influencing the hydrolysis among weight of cocoa pod shells, concentration of HCl and duration of autoclave. Parameters such as concentration of HCl and duration of autoclave were found to be significant. These parameters were chosen for the central composite design comprising of five levels using response surface methodology to optimize the hydrolysis process. At optimized condition of 54.15 minutes of autoclave treatment and 4.41% of HCl, 21.11 g/L of maximum reducing sugar was released. A second order polynomial equation was generated having a good fit with R2 of 0.84.
To release reducing sugars from cocoa pod shell, sulphuric acid pre-treatment was adopted where the variables affecting H2SO4 pre-treatment i.e., cocoa pod shell weight, H2SO4 concentration, ...microwave irradiation time and power were screened using one factor at a time approach. The weight of cocoa pod shell, concentration of H2SO4 showed a significant effect on the pre-treatment process and the levels of these factors were further optimized by central composite design using response surface methodology .The optimized conditions were found to be 15.65g ofcocoa pod shell, 6% v/v H2SO4 at 8 min of irradiation, released maximum reducing sugar of 9.10 g/L. A second order model was generated and validated, which was found to be a good fit with R2value of 0.89. Artificial neural network modelling proved validation R2 of 0.94 comparatively better than Response surface methodology R2 of 0.89. The reducing sugars released after acid hydrolysis at optimized conditions were subjected to fermentation by Pichia stipitis to produce bioethanol. The bioethanol produced was 3.2g/L at 2% (v/v) inoculum concentration after 72h of fermentation.
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