Antioxydants in organic and traditional sunflower seed oils.

The increasing awareness of consumers about food and health, and the potential or real contamination problems of some foodstuffs has created and increasing demand for foods that the consumers perceive as "natural and genuine". For these reasons the importance of the organic agriculture is growing and nowadays products obtained with organic agriculture are of the utmost interest for the food as well as for the cosmetic and pharmaceutical industries. In the last 30 years the world production of sunflower seeds has had a significant increase compared to other seed oil cultivation and in Italy there are about 250.000 hectare destined to sunflower cultivation, mainly located in the central and Southern regions. Sunflower seeds are very rich in oil (about 50% by weight) and from a chemical point of view the oil is considered very good for human consumption, because of its high ratio polyunsaturated/saturated fatty acids and the high content in linoleic acid. The production of an organic seed oil must be based on technical processes that respect the principles of the organic agriculture, therefore it is not possible to use toxic and pollutant organic solvents such as hexane. However, extraction by just pressing the seeds has often a limited economical value because of the high amount of oil that remains in the pressed cake, even if the final content in natural antioxidants of the oil is not significatively affected by the pressing process. This is important for sunflower oil that is richer in vitamin E (about 650 ppm of alfa-tocopherol) than many other edible oils, and therefore is very important to preserve this antioxidants fraction. A possible alternative could be represented by the use of the supercritical fluid extraction technology based on the utilization of CO2 at supercritical conditions, a substance that has the status of "generally recognized as safe" (GRAS). The aim of this work was to evaluate, with special attention to the tocopherol fraction, the quality of an organic sunflower oil extracted using a "mild technology" with low environmental impact such as supercritical CO2, with the quality of organic and non organic sunflower oil produced with traditional extraction techniques.