Best combination of bleaching parameters on quantitative and qualitative characteristics of sunflower and corn oils using response surface methodology

The bleaching process is important in the refining operation of edible oils. In this study, bleaching parameters were changed to evaluate the best condition for optimizing of bleaching in corn and sunflower oils. For this purpose, the effect of time (15, 25, 35, 45, and 55 min), temperature (80, 90, 100, 110, and 120 °C), and bleaching clay concentration (0.4, 0.6, 0.8, 1, and 1.2%) was evaluated using response surface methodology as statistical design in 5 levels by Central composite design with the aim of reducing the consumption of bleaching clay. The studied factors were including carotenoids, sterols, tocopherols, pigment and cations. After optimization, the best conditions for bleaching of corn and sunflower oils was different. For corn oil, the best conditions was time 39.59 min, temperature 103.61 °C, and bleaching clay concentration 1%, which meet 67% of our expectations. For sunflower oil with the aim of reducing the consumption of bleaching clay, the best conditions were time 37.49 min, temperature 97.53 °C and bleaching clay concentration 1%, which satisfied 70% of our expectations. The practical results did not show any significant differences with obtained theory values ​​using response surface methodology and confirmed these results.