Document Type: Research Article
Moghan College of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, I.R. IRAN
Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, I.R. IRAN
The effects of hot air temperature (40, 50 and 60 oC) and radiation intensity (RI) (0.21, 0.31 and 0.41 w/cm2) on the response variables (drying time, head parboiled rice yield (HPRY), color value and hardness)) of parboiled rice were investigated. The drying was performed using hybrid hot air–infrared drying. The optimization of drying variables and the relationship between response variables and the influence factors were analysed using response surface methodology (RSM). Based on RSM results, the best mathematical model for prediction of HPRY, hardness and color value and drying time of samples was linear(R2= 0.96), quadratic(R2= 0.99), linear(R2= 0.93) and linear(R2= 0.99) equation, respectively. The HPRY (62.13- 68.13%) and hardness (130.27- 247.3 N) increased with increasing drying temperature and RI, while the color value (19.77- 18.03) and drying time (59.72- 34.41 min) decreased. The optimized parameters of drying were obtained 55 oC drying temperature and 0.41 w/ cm2 RI.