Physical and chemical characteristics of Silybum marianum seed oil

Introduction and cultivation of new oilseeds، is an important step to provide needed oil for the country. Milk thistle (Silybum marianum) is an annual or biennial plant that the extract of its leaf or seed has been used for treatment of liver diseases since 2000 years ago. In spite of compatibility of this plant to climate of Iran especially resistance to dryness، there is no information about the content and quality of the seed oil. In this study، the oil content was determined by Soxhlet and it was 22. 7%، nearly similar to soybean and cottonseed (dehulled) oil content. Refractive index، Color and Specific gravity and Peroxide (1. 59)، Iodine (109. 57)، Saponification (180. 9) and Acid (1. 82) values of the oil were studied. Also، fatty acid profile of the oil was determined by GC. Linoleic acid (51. 2%) and oleic acid (28. 8%) were the most fatty acids of the oil، respectively. In regard to remarkable oil content of the seed and high nutritional value of the oil (high-linoleic acid)، cultivation of this new valuable oilseed is necessary and beneficial.