A comparative study on performance of industrial and microwave techniques for sunflower oil bleaching process

The main objective of this study is to compare the quality characteristics of the sunflower oils bleached with microwave and industrial techniques. The bleaching efficiencies of microwave and industrial bleaching methods were found as 83.76% and 85.68%, respectively. The totox values of bleached oil were found as 22.39 and 18.86 in microwave and industrial bleaching, respectively. The free fatty acid content was almost not changed with microwave bleaching, it was decreased by the industrial bleaching. No significant difference was reported in tocopherol content and sterol composition of oil after both industrial and microwave methods. The amount of clay and the bleaching time were reduced by 50% and 73%, respectively in microwave bleaching. The possibility of the repetitive use of bleaching clay was also evaluated and it was found that the clay used in microwave bleaching was efficient at least twice for bleaching of sunflower oil.