Optimization of sunflower oil bleaching parameters: using Response Surface Methodology (RSM)

Abstract Bleaching is an important part of the oil refining process, in which pigments, impurities, traces of metals, and oxidative-molecular components of oils are removed. In this regard, the optimization of bleaching conditions can be effective to increase oil quality. In this study, de-gummed and neutralized sunflower oil was bleached at 80, 90, 100, 110, and 120 °C for 15, 25, 35, 45, and 55 min by acid-activated bleaching clay with the concentrations of 0.4, 0.6, 0.8, 1, and 1.2% under laboratory conditions. At that point, peroxide, anisidine, plus Totox values, free fatty acid content, Rancimat, and specific UV absorption at 232 and 270 nm were analyzed via the RSM method. The model optimization using the RSM method revealed that the optimal conditions were 37.31 min, temperature 92.7 °C, and clay concentration 1.18%; this circumstance can meet 86.7% of the expectations as could be met for reducing the factors effective for oxidization during bleaching.