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Thermal properties of expanded amaranth seed oil
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1  Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences (WULS – SGGW), Nowoursynowska st. 166, 02-787 Warsaw, Poland
Academic Editor: Manuel Viuda-Martos


Amaranth was present both in the culture and in the cuisine of the peoples of South America already in pre-Columbian times. This pseudocereal is valued for its high content of vitamins, calcium, iron and squalene. The seeds are also used to produce oil and as a snack in the form of expanded amaranth. Thermal properties of oils are a very important distinguishing feature of their quality and stability. Based on the knowledge of the oxidation time, studied with a differential scanning calorimetry, it is possible to determine the susceptibility of the tested oil to oxidation.

The aim of the study was to analyse the properties of fat extracted from extruded amaranth seeds by thermal and chromatographic methods.

The analyses of melting characteristic was performed using a TA DSC Q200 differential scanning calorimeter. All measurements were conducted under a nitrogen atmosphere. Before the test, the sample was stored in refrigerated conditions. The oil was weighed in the amount of 3-4 mg and sealed in hermetic aluminium vessels. The samples were cooled to -80°C and then heated to 80°C at a rate of 5°C/min for melting profile analysis.

Three peaks present on the DSC melting curves of amaranth oil, were connected with the presence of low-melting triacyloglicerols with polyunsaturated fatty acids (first peak) and medium-melting fraction rich in triacyloglicerols with monounsaturated and saturated fatty acids (second and third peaks). Oxidation time analysis was performed using a TA PDSC Q20 pressure differential scanning calorimeter. The oil was weighed in the amount of 3-4 mg into an open aluminium vessel. The samples were then heated from room temperature to 120°C, 130°C and 140°C. All measurements were made under an oxygen atmosphere. PDSC analysis showed good resistance of the oil to oxidation.

The composition of fatty acids in the studied amaranth oil showed a high content of essential fatty acids.

Keywords: expanded seeds, amarant oil, differential scanning calorimetry.