Oil Expelling from Dehulled De-Skinned Groundnut Kernel using Screw Press: Optimization of Process Parameters and Physico-chemical Characteristics

Screw pressing parameters for oil expelling was optimized with dehulled deskinned groundnut and wheat bran (fibre material) at variable sample moisture and press head temperature in two different sets of experiments. Box-Behnken design of response surface methodology was adopted for the study with dehulled deskinned groundnut (80-95g), wheat bran (8-16g) and sample moisture (8-14%, w.b.) while press head temperature ranged between 50-90 oC. Oil expelling properties viz. oil recovery, residual oil, press rate, sediment content in oil, oil and meal temperature, free fatty acid (FFA) value were considered as dependent variables. Oil recovery and residual oil in cake was affected due to change in composition of wheat bran, dehulled and deskinned groundnut, sample moisture and press head temperature. The study concluded that 85.6% dehulled deskinned groundnut kernel and 14.4% wheat bran with 8% moisture content could be considered for screw pressing of dehulled deskinned groundnut at 66.5ËšC press head temperature.