Evaluation of Oil Content, Fatty Acids Profile and Phytosterols of Milk Thistle (Silybum marianum L.) Oil in Several Different Ecotypes in North -West of Iran

Silybum marianum (Family: Astraceae) is an annual or biennial plant, which it grows in the most regions of Iran. The extracts of the mature milk thistle seeds are used as medicinal compounds against liver diseases and liver cirrhosis and inhibitor of liver cancer. In this study, oil content,fatty acids profile and phytosterol compounds were determined in three ecotypes which are in north-west of Iran including Khoreslo, Moghan (in Ardabil) and Babakcastle (in East Azerbaijan). The extracted oil contents of the seeds were from 28% to 29.5%. linoleic acid (49-52%) was predominated followed by oleic acid (25-29%) and linolenic acid was in the lowest level in the all samples. Moreover, phytosterols such as β-Sitosterol, Stigmasterol, Campesterol, Cholesterol, Cleroesterol and ∆7- Sterol were determined in the all extracted oil samples by GC, which β-Sitosterol was the highest in comparison to the others in the all samples. Therefore, the highest content of β-Sitosterol (34.9% of total phytosterol) among the three different ecotypes was belonged to Khoreslo ecotype. In conclusion, using of milk thistle seed oil which has high nutritional value is beneficial in production of edible oil in the country.