Investigation of the Chemical Characteristics and Oxidative Stability of Some Commercial Cold-Pressed Oils

Abstract

In this study, the chemical composition and oxidative stability of cold-pressed flaxseed, black seed, pumpkin seed, walnut seed, and poppy seed oils were examined. The results showed that the seed oils contained appreciable amounts of unsaturated fatty acids (above 79 %). Polyunsaturated fatty acids, particularly linoleic acids were dominant, with values ranging from 53.24 % -71.37 % of the total amount of fatty acids except for pumpkin seed oil. Tocols content was found to be between ~ 490-932 mg kg -1 , and the flaxseed oil exhibited the highest levels of total tocopherols (977.47 mg kg -1 ) under the experimental conditions. While, the highest PV was found in walnut seed oil (2.81 meq O2 kg -1 ), and the highest content of FFAs was reported for flaxseed oil (1.82 %). OSI values were 4. 15, 3.57, 4.31, 3.98 and 4.92 h for the flaxseed, black seed, pumpkin seed, walnut seed, and poppy seed oils, respectively. The obtained data suggest that the seed oils in this study may serve as special dietary sources.