Non-Normative Oxidation Stability Indication of FAME Produced from Rapeseed and Used Cooking Oil

The article describes the mechanism of oxidation of polyunsaturated fatty acid esters and presents the effect of temperature as one of the factors accelerating this process. The consequences of aging for ester-based biofuels are discussed extensively. The article presents the results of aging of FAMEs obtained from frying oil and of FAMEs derived from unrefined rapeseed oil to examine the influence of temperature as a factor accelerating aging. Acid, peroxide and anisidine values were determined for each sample; additionally, IR spectra were measured. Based on the results, it was confirmed that temperature has a significant effect on the degradation of FAMEs. These changes are best represented by the anisidine value and the change in IR spectra. The paper presents the relationship between acid, peroxide and anisidine values. This paper also highlights the beneficial effect of natural antioxidants in the form of β–carotene, which is found in FAMEs derived from unrefined rapeseed oil.