Determination of Chemical Properties of Cold Pressed Oils Sold in Istanbul Market

Abstract

Vegetable oils are important in human nutrition with their nutritional properties. Today the demand for cold pressed oils, especially black cumin, is increasing day by day. In this study, it was aimed to evaluate the quality and characteristics of the oils consumed and sold by highlighted as cold pressed as food supplements in terms of food safety. In the study, % free fatty acidity (FFA), peroxide values (PV), fatty acid compositions and iodine numbers of samples (six brands and four varieties; black cumin, wheat germ, grape seed and apricot kernel) sold in the Istanbul market were investigated. According to results, average FFA values were 8.1% in black cumin, 1.43% in germ, 1.90% in grape seed, 4.31% in the apricot kernel. Average PVs (meq O2 kg-1 oil) were 24.30 in black cumin, 21.42 in germ, 12.39 in grape seed, 26.23 in the apricot kernel. Total(Σ) SFA, MUFA, PUFA values were determined between 7.14-11.42%, 16.43-42.78%, 29.09-48.81% in black cumin; 6.83-11.35%, 22.64-51.87%, 22.27-54.87% in germ; 6.89-11.86%, 22.68-41.82%, 30.76-44.27% in grape seed; 5.62-10.29%, 22.58-59.24%, 21.15-43.93% in apricot kernel, respectively. Also, average iodine numbers (g I2 / 100 g oil) were calculated 95.17 in black cumin, 97.58 in germ, 99 in grape seed, 92.62 in the apricot kernel. Since only grape seed oil is included in the Turkish Food Codex, evaluation of the other samples couldn’t be made according to the Codex. It was determined that the PV value of 2 grape seed oil samples and the FFA value of 3 samples were not suitable according to the communiqué. The differences in the analysis results are thought to be caused by raw material quality and storage, process and final product storage conditions.

Keywords

• cold pressed oils
• ffa
• peroxide values
• fatty acids composition
• iodine value