Assessment of chemical characteristics of repeatedly fried edible oil

The repeated use of edible oils to fry food has been a long-standing practice. Unfortunately, many people, especially in developing countries, are unaware of the health risks associated with consuming such oils. In this study, palm olein oil, the most commonly used edible oil in Nigeria, was used to fry fish three times, and ten times. Samples of fresh (non-fried), three-times fried, and ten-times fried oil were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The analysis revealed that oleic acid (9-octadecenoic acid) was the primary chemical constituent in fresh palm olein oil, accounting for 33.48% of its composition. Other components in fresh palm olein oil included hexadecanoic acid (7.08%), 9,12-octadecanoic acid (8.16%), and benzene derivatives such as nonyl benzene (3.49%) and octyl benzene (2.895%). The three times fried oil contained 17.08% oleic acid, along with cholesterol, 2-Ethylacridine, 2,4,6-Cycloheptatrien-1-one, and Cyclotrisiloxane, hexamethyl. The ten times fried oil contained 14.15% oleic acid, 3.40% cholesterol, 11.69% 2-ethylacridine, 19.15% 2,4,6-Cycloheptatrien-1-one, 15.54% 1,4-Bis-(trimethylsilyl)-benzene, and 23.08% 1,2-Benzisothiazol-3-amine. The findings of this study suggest that with an increase in the number of frying times, the nutritional quality of the oil decreases, and more cyclic aromatic hydrocarbons are generated. These hydrocarbons have been linked to the development of chronic diseases, including cancer and cardiovascular diseases.