Determination of the fatty acids composition of refined sunflower oil and possibility of its changing during storage period

Abstract

Refined sunflower oil is an auxiliary component of many dosage forms made in pharmacy. For their preparation, pharmacies purchase oils from different manufacturers and have the right to use it throughout the shelf life. However, the question arises of maintaining the stability of the fatty acid composition of the oil because of the influence of various environmental factors. In previous studies, the authors investigated the change in the composition of basic fatty acids (FA) of sunflower oil during heating or long-term storage, but there are no studies of the full FA composition of sunflower oil, as well as an assessment of its dependence on the period of the oil using. The aim. Detailed study of the FA composition of refined sunflower oil from different manufacturers, assessment of the effect of the shelf life of the oil on its FA composition and its compliance with the requirements of the European Pharmacopoeia (EP). Materials and methods. The determination of the FA composition of seven samples of refined sunflower oil was carried out by gas chromatography with a flame ionization detector using the Rt-2560 column (100 m×0.25 mm×0.20 µm). Results. The analysis of seven samples of refined sunflower oil showed the presence of 24 FA in most of them. Polyunsaturated FA predominate among them with a percentage of 52.45-60.86 %. The value of the fatty acids percentage in each groups (saturated, mono- and polyunsaturated fatty acids) are quite similar regardless of the oil shelf life at the time of the research. All test samples, except one, by the percentage content of the main FA correspond to EP requirements. The results of the quantitative content of the main FA of sunflower oil determining (palmitic, stearic, oleic, and linoleic) also indicate a similar FA composition of the studied samples. Conclusions. The studied samples of sunflower oil refined in terms of the content of basic FAs meet the requirements of the EP. The obtained results indicate the high stability of the oil and the absence of a significant effect of the storage period on the FA composition.