Physicochemical characteristics, fatty acid positional distribution and triglyceride composition in oil extracted from carrot seeds using supercritical CO2

• Fatty acid profiles for carrot seed oil TAG were determined.
• Carrot seed oil was comprised of mainly oleic acid.
• Melting and crystallization of carrot seed oil was influenced by fatty acid profile.
• Oxidative stability of carrot seed oil was under Regulatory limits.
• Information for nutritional and oxidative quality of carrot seed oil is provided.

New Zealand carrot seed oil extracted by supercritical fluid CO2 was analyzed for its fatty acid composition, color, quality, melting and crystallization, triglycerides fatty acid composition and positional distribution of the fatty acids. The oil was yellowish in color and its peroxide value, p-anisidine value, total oxidation value, free fatty acid content, acid value, conjugated diene and triene value, unsaponifiable matter content and polar compound level were all lower than the maximum limits of guidelines for edible oils. The melting and crystallization profiles of carrot seed oil were assessed by Differential Scanning Calorimetry (DSC). Both of them occurred in two distinct regions which are related to the fatty acid composition. The major fatty acid of carrot seed oil was oleic acid (81.5 ± 1.7%; p < 0.05). Four major triglyceride peaks were collected via high performance liquid chromatography, identified by electrospray ionization-mass spectroscopy and confirmed by gas chromatography. They were trilinoleoyl-glycerol (LLL)/linolenoyl-linoleoyl-palmitoyl-glycerol (LnLP), dilinoleoyl-oleoyl-glycerol (LLO)/dilinoleoyl-palmitoyl-glycerol (LLP), dioleoyl-linoleoyl-glycerol (LOO)/linoleoyl-palmitoyl-oleoyl-glycerol (LPO) and trioleoyl-glycerol (OOO). Saturated fatty acids in carrot seed oil predominated at sn-1,3 positions, while polyunsaturated fatty acids were found mostly at the sn-2 position with C18:1 being more evenly distributed.