Background. Vegetable oils are a known source of mono- and polyunsaturated fatty acids (MUFA and PUFA). The growing demand for vegetable oils, rich in unsaturated fatty acids, increases the use of new oil plants to obtain them. In this study, the physicochemical properties (density, pH, refractive index, dynamic viscosity, contact angle, surface tension, color) were examined, a spectroscopic analysis was carried out and antioxidant properties were determined. In order to determine the indicated parameters, simple and easily accessible analytical methods were used, which provide key information about the properties of oils and serve as indicators for assessing their quality. Six commercially available oils were selected for the study: evening primrose seeds (Oenothera paradoxa), milk thistle seeds (Silybum marianum), pumpkin seeds (Cucurbita oleo), linseed (Linum usitaissimum L.), winter camelina seeds (Camelina silvestris) and black cumin seeds (Nigella sativa).
Results and conclusions. The conducted research provided significant insights into the relationship between the determined parameters of vegetable oils. The positive correlation between density and refractive index also highlights the influence of fatty acid composition on these properties. The observed diversity of colors of the oils tested highlights the unique composition of dyes characteristic of each oil. It was found that the pH of vegetable oils is a key indicator reflecting the level of acidity in the oil. The correlation between contact angle and surface tension revealed complex surface interactions.