The effect of supercritical carbon dioxide extraction of amaranth oil-cake on the yield of the extract and its squalene content

Abstract

The contents and compositions of the oil, carbohydrates and protein of oil cake of amaranth of the universal variety «Kharkovsky-1» were studied. It was found that cake contains up to 4.5% oil with 5.4% squalene, 65.95% crude carbohydrates with a predominance (50.55%) of water-soluble polysaccharides and 27.7% protein. The effect of a pressure of 80–200 bar and an extraction time of 30–120 min with CO2 extraction on the yield of the crude extract, the oil phase of the extract and the content of squalene in them was studied. It was found that the optimal conditions are a pressure of 90 bar and an extraction time of 30 minutes at a temperature of 50 °C; under these conditions, 6.6% crude CO2 extract with 17.8% squalene was obtained. Experiments with supercritical carbon dioxide extraction of oilcake impregnated with ethanol with a hydromodule feed: a 2: 1 co-solvent showed that ethanol does not significantly affect the squalene content in the oil phase of the CO2 extract. More than 62.4% of crude carbohydrates consisting of 3.0% alcohol-soluble sugars, 42.2% water-soluble polysaccharides, 7.8% pectin substances, 2.4% hemicelluloses and 7.0% fiber were found in meal after CO2 extraction of oilcake. The protein content in amaranth meal after CO2 extraction was 22.6%.