Optimization of a De-skinning process parameters for roasted peanuts

Peanuts are de-skinnig by abrasion provided by abrasive rolls mounted on a horizontal shaft in de-skinner machine. The RSM and CCRD were used for optimization of de-skinner machine parameters for roasted peanut. The rotational speed (1000-1400 rpm) of de-skinning roller and outlet opening (4-18 mm) of de-skinning machine were taken as independent variables. The response variables were considered as a De-skinning efficiency (%), output capacity (kg/h) and specific energy consumption (kWh/kg). The regression coefficients of the linear, quadratic polynomial models for the response variables were generated. The performance of machine was significantly affected by the moisture content of grains and the speed of the mill. The individual and interaction terms of roller speed, and outlet opening of the de-skinning machine on the de-skinning efficiency, specific energy consumption and output capacity were highly significant (p ≤ 0.01, p ≤ 0.05) with respective  R2  values 0.95, 0.98, 0.98.  The de-skinning efficiency ( 90.54 ± 1.2 %), capacity (44.5 ± 2.4 kg/h) and specific energy consumption (0.0314 ± 0.045 kW h/kg) were obtained for roasted peanut with optimum machine operating parameter viz. roller speed 1300-1400 rpm and outlet opening 4.6- 9.6 mm. This study will help to small scale venders to optimize the de-hulling process.