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

Conduction Roaster for Accelerated Roasting of Peanut

Roasting is one of the thermo-mechanical operation in cereals and oilseeds processing. Low-capacity machine for mechanisation of roasting is necessary for small-scale processing. A conduction-type motorised rotary roaster (8 kg per batch) was designed and developed for roasting of peanuts. Performance of the roaster was evaluated in terms of moisture loss, scorched kernels, and specific energy consumption for accelerated roasting of peanut. The effects of different roasting conditions were studied to determine the optimum operating conditions of the roaster. Quality indices of peanuts as moisture loss (kg.kg-1), scorched kernel (%), and specific energy consumption (kWh.kg-1) were dependent on the operating conditions. The optimum value of moisture loss (0.041± 0.003 kg.kg-1), scorched kernel (0.93± 0.0.004 % ), and specific energy consumption (0.185 ± 0.005 kWh.kg-1) were obtained at roasting temperature of 170°C, roasting time of 15 min, and rotational speed of 20 rpm for roasting peanut. The roasting characteristics of peanut decreased linearly with increase in the temperature and time; and decrease in the rotational speed. The inferior quality parameters were observed at higher temperatures, speed and medium time of roasting. The study indicated optimum roasting temperature of peanut to be 170°C, and further increase in the process temperature had undesirable effects on roasted peanut quality due to high loss of moisture

Physical and Thermal Properties of Potato Flour as Influenced by Moisture Content

The physical, thermal and flow properties (flowability) of potato flour from Kufri-Chipsona, Kufri Sinduri and Kufri Badshah varieties produced in West Bengal, Rajasthan and Bihar states were evaluated. Moisture content was the important variable affecting these properties. Within moisture ranges of 7.04 % to 56.25 % (d.b.) the bulk, tapped and true density and porosity significantly decreased with increase in moisture content of potato flour of each variety, and ranged from 350-690 kg.m-3, 640-1240 kg.m-3, 1510-1550 kg.m-3 and 54-71 %, respectively. Carr index and Hausner ratio ranged from 24.41-44.50 %, and 1.32-1.77, respectively. Thermal conductivity, specific heat and thermal diffusivity of the flours significantly (p<0.05) increased from 0.125 to 0.230 W.m−1.K−1, 0.092 to 0.124 mm2 .s-1 and 1.13 to1.76 MJ.m-3.K-1, respectively, when moisture content of flours increased from 7.04 % to 56.25 % (d.b.)