Investigating the quality of vegetable oils in the Iranian consumer market by comparative evaluation of oxidative parameters and fatty acid profiles

Abstract

Oil has been one of the necessary ingredients for cooking around the world. As food industry proceed, better and more useful oils with their own characteristics are being offered to consumers every day. In the current research, in order to investigate the quality of soybean, frying and deodorized olive oils available in the Iranian consumer market, physicochemical parameters such as peroxide index, acidity, iodine index, saponification index, as well as their fatty acids profile and oxidative stability were determined and then compared. All physicochemical parameters except olive oil peroxide index were consistent with the standards. The peroxide index in olive oil (9.61 meqo2/Kg) indicated that olive oil was inappropriate for frying. 0.97 meqo2/Kg peroxide value was reported in soybean and frying oils. The fatty acids profile showed that oleic acid was the predominant fatty acid in olive oil, while in frying oil palmitic, oleic, and linoleic acids were significant. Also, linoleic acid in soybean oil as the predominant fatty acid was determined. The oxidative stability of frying and soybean oils, according to the Rancimat method, was higher than that of olive oil (P0.05).