Characteristics of Biologically-Active Substances of Amaranth Oil Obtained by Various Techniques

Amaranth seeds and their main product amaranth oil are a rich source of bioactive substances. The non-saponifiable substances which accompany lipids include: squalene, tocopherols, sterols and others. The aim of the study was to compare the content of squalene, tocopherols and phytosterols in amaranth oils obtained by various techniques. The oil was extracted from seeds (Anzaranthus motto) with the use of supercritical fluid extraction (SFE), extraction with a chloroform/methanol mixture and expeller pressing. Contents of squalene and tocopherols were determined with high performance liquid chromatography (HPLC) method. The content of sterols in oils was determined by gas chromatography coupled with mass spectrometry (GC-MS). The highest squalene content was found for the oil obtained as a result of supercritical CO2 extraction (6.95 g/100 g of oil). A lower content of squalene was noted in the oil extracted with organic solvents and in cold-pressed oil 6.00 and 5.74 g/100 g of oil, respectively. The amaranth oils were characterised by a significant content of tocopherols. The oil obtained as a result of fluid extraction was characterised by the highest content of tocopherols (131.7 mg/l00 g of oil). A dominating homologue (40%) was beta-tocopherol. Also the same sample was characterised by the highest content of sterols (2.49 g/100 g of oil). In all samples the predominating sterol was sum of a-spinasterol and sitosterol, which accounted for 45%, 56% and 53% of total analysed sterols for the oil obtained from SFE, from extraction with solvents and from cold pressing, respectively.