Effects of refining process on sunflower oil minor components: a review

Sunflower oil is well known because of its diversity of fatty acids profiles which allow different uses (food: dressing salads, margarines; nonfood: agrofuel, lubricants). Besides, crude oil contains high amounts of desirable minor components (tocopherols, phytosterols, polyphenols, phospholipids...) that present important nutritional features with a positive impact on human health. The different steps of the refining process have as main objective to remove contaminants and other compounds that could hamper the continuity of the process or alter oil during storage. An indirect consequence of this treatment used to preserve food safety is that micronutriments of interest are also partially eliminated reducing the nutritional quality of the oil. This review describes in the first part the chemical composition of sunflower oil focusing on desirable and undesirable components. In the second part the refining process is detailed following the losses of micronutriments at each step of the process and the elimination of unwanted compounds.