Physicochemical Properties of Garden Cress (Lepidium sativum L.) Seed Oil

Garden cress (Lepidium sativum L.) is an edible,
underutilised herb, grown mainly for its seeds in India.
Physicochemical properties, minor components (unsaponifiable
matter, tocopherols, carotenoids), fatty acid composition
and storage stability of garden cress seed oil (GCO)
were studied. Cold press, solvent and supercritical CO2
extraction methods were employed to extract the oil. The
total oil content of garden cress (GC) seeds was 21.54, 18.15
and 12.60% respectively by solvent, supercritical CO2
and cold press methods. The physical properties of GCO
extracted by the above methods were similar in terms of
refractive index, specific gravity and viscosity. However,
cold pressed oil showed low PV and FFA compared to the oil
extracted by other methods. a-Linolenic acid (34%) was the
major fatty acid in GCO followed by oleic (22%), linoleic
(11.8%), eicosanoic (12%), palmitic (10.1%) erucic (4.4%),
arachidic (3.4%) and stearic acids (2.9%). Oleic acid
(39.9%) and a-linolenic acid (42.1%) were the predominant
fatty acids at the sn-2 position. The total tocopherol and
carotenoid content of GCO was 327.42 and 1.0 lmol/100 g
oil, respectively. The oil was stable up to 4 months at 4 �C.
Tocopherol and BHT offered the least protection, while
ascorbyl palmitate (200 ppm) offered the maximum
protection to the oil, when subjected to the accelerated
oxidative stability test. Thus GCO can be considered as a
fairly stable oil with a high content of a-linolenic acid.