Vegetable oils play a very important role in the cosmetic and pharmaceutical industries and medicine. Vegetable oils are manly triglycerides, a small amount in their composition is represented by unsaponifiable matter.
Our research is a part of another research, in which we are studying characteristics of vegetable oils and their effect on human skin. In our research, we determined the fatty acid composition of triglycerides and antioxidative activity of seven vegetable oils. We selected five vegetable oils, based on their fatty acid composition of triglycerides; these were pomegranate seed oil (characterised by punicic acid), flax seed oil (α-linolenic acid), coconut oil (lauric acid), olive oil (oleic acid) and poppy seed oil (linoleic acid). In addition, two less-known oils were extracted by n-hexane extraction out of their seeds, i.e. Tilia and Calendula seed oils. Tilia seed oil contains a high amount of linoleic acid, while Calendula seed oil contains a high amount of calendic acid.
Determination of chemical numbers and isolation of unsaponifiable matter was performed according to Pharmacopoeial procedures (1, 2). Most of the oils were suitable. Peroxide value was low in most cases (from 0,6 to 19,3). Iodine and hydroxyl values were the highest in pomegranate oil (II=192 and IOH=36,10). We can conclude that high iodine value is due to high amount of unsaturated fatty acids. Acid value was also the highest in pomegranate oil (IA=3,56), while saponification and ester values were the highest in coconut oil (IS=265 in IE=265). Using GC-MS analysis we determined the fatty acid composition, which was in accordance with literature data. We also determined the content of unsaponifiable matter and antioxidant activity. The highest antioxidant activity was found for pomegranate seed oil (around 49 %) and around 30 % for Tilia seed oil, Calendula seed oil and olive oil. Based on the fatty acid composition of triglycerides and high value of antioxidative activity, we concluded that Tilia seed oil and Calendula seed oil are most interesting for further studies to find potential use of these two oils. Current lack of usage of these two oils are probably due to other uses in medicine and pharmacy and time-consuming extraction.