Destino degli antiossidanti nativi nella raffinazione fisica dell’olio di palma grezzo

Crude palm oil is a good source of natural antioxidants, such as tocopherols and carotenoids. However crude palm oil is not edible and is generally refined by the physical process. The aim of this work was to study the fate of native antioxidants during palm oil bleaching and steam refining, performed with synthetic silica and various types and concentrations of clays. Bleaching removed 20-50% of the carotenes, depending on clay concentration and activity. After steam refining carotenes were quite totally destroyed. Tocopherols concentrations increased after the treatment with the most acid bleaching clay, and the increase was proportional to the amount of clay used. In particular, bleached palm oil resulted enriched in α-tocopherol and α -tocotrienol. The last increased during steam refining, too. The operative conditions of the refining process carried out gave about an 80% recovery of palm oil tocopherols.