MIHAELA GABRIELA DUMITRU OBTAINING BIODIESEL WITH HIGH OXIDATION STABILITY FROM THE OIL BLEND EXTRACTED FROM SEEDS OF CITRULLUS LANATUS AND VITIS VINIFERA The increase of energy demand associated with stringent worldwide emission legislation and the depletion of fossil resources has led to the use of biodiesel and biodiesel blends from various feedstocks. One of the main problems with biodiesel is the susceptibility to oxidation and degradability due to the environmental factors. The oxidation process is complex affecting the fuel quality resulting in choking of injector and formation of deposits in fuel system. Antioxidants are used to limit the oxidative degradation. The present paper review some attempts to use natural and synthetic antioxidants form different papers available in the public domain. Two types of biodiesel from oils of Citrullus lanatus and Vitis vinifera were obtained by base catalyzed transesterification. Peroxide value, iodine value, acid value and induction period were determined monthly to observe the degradation process for biodiesel samples. The biodiesel from Citrullus lanatus 90% and oil of Vitis vinifera 10% exhibits presented the best oxidation stability over a period of 12 months. A single cylinder diesel engine setup was used to determine the performance and gas emissions for biodiesel samples. The results show that biodiesel can be used without engine modification with results comparable with diesel fuel.