FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

IZA BAJERLEIN, PATRYK BIELECKI

Title

Determination of the profile of fatty acids in extracts obtained by supercritical carbon dioxide extraction from stinging nettle leaves (Urtica dioica L.)

Abstract

Ecological plant extracts, that are rich in biologically active substances, are a valuable raw material for the food industry, thus new sources thereof are constantly searched for. Special attention is paid to common plants that are resistant to difficult weather conditions, easily available and inexpensive to grow. This type of plants includes  stinging nettle (Urtica dioica L.). The objective of the research study was to determine the profile of fatty acids  contained in stinging nettle leaves, in extracts obtained by an extraction method using supercritical carbon dioxide with the addition of ethanol. There were obtained 5 extracts that differed in the method of obtaining them and in  the process parameters – time, pressure and temperature. A GC-MS method was applied to determine the fatty  acid profile. To identify the compounds, mass spectra were compared with the NIST 11 library as were retention  times with a certified reference material. In all the extracts the content of unsaturated fatty acids was higher than  that of saturated fatty acids. The research study showed that the increase in temperature and pressure resulted in  washing out a greater amount of desirable unsaturated fatty acids. The highest content of unsaturated fatty acids  was reported in the extract obtained at a temperature of 50 ºC and a pressure of 250 bars. In the extracts obtained  using a low pressure and an extended extraction time was not identified eicosapentaenoic acid, which was present  in the remaining samples.

Keywords

stinging nettle, supercritical carbon dioxide extraction, gas chromatography, profile of fatty acids

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