Composition and thermal characteristics of seed oil obtained from Chinese amaranth.

Amaranthus tricolor and Amaranthus dubius are the most prevalent vegetable amaranths in China. The fatty acid composition, triacylglycerol (TAG) profile, vitamin E and sterol content, and thermal properties of seed oils extracted from these two vegetable amaranths were investigated in this work. The results reveal that the seed contains ∼8% oil. The main fatty acids in the oils are linoleic (51.5–53.5%), oleic (14.8–18.4%), palmitic (15.7–17.1%) and stearic (3.6–4.1%). PLL (∼22%), LLL (∼20%), LLO (∼17%) and POL (∼11%) are the dominant TAGs in the oils. The amaranth seed oils exhibit a distinct melting and crystallization profile that consists of 5 endothermic peaks and 2 exothermic peaks. The oils are rich in vitamin E (705–829 mg/kg) with δ-tocopherol as the major component. The two oils have similar total sterol contents (2488.7 and 2762.1 mg/100 g) but different individual sterol percentages. The higher contents of oil, linoleic acid, vitamin E, and sterols make the amaranth seed oil desirable in terms of nutrition. • Properties of seed oil from vegetable amaranth were comparatively investigated. • The oil of vegetable amaranth contained more linoleic acid. • The vitamin E and sterol profile of vegetable amaranth oil is different from those of grain amaranth. • The thermal properties of amaranth seed oil were first reported. • Amaranth oil is a good source for developing high-quality vegetable oil. [ABSTRACT FROM AUTHOR]