Effect of sowing location on oil content and fatty acids composition of medicinal Castor bean plant (Ricinus communis L.)

Castor bean (Ricinus communis L.) is one of the most important medicinal plants used in pharmaceutical, cosmetics and hygienic industries in many developed countries. Oil obtained from plant's seeds is of the most valuable aperients in medicine. The purpose of this research was determining the effects of climatic factors (seven different locations) on oil content and fatty acids composition of castor bean plant and increasing quantity and quality of oil. The results showed that climatic factors had significant effects on oil content and fatty acids composition and there were significant differences among the different climates (P<0.01). The highest oil content was reported from West of Tehran (52%) and Marand (51%) regions. Based on the results of fatty acid analysis by Gas Chromatography (GC), eight major fatty acids were observed in castor oil. Ricinoleic acid (18:1 Δ9c-12OH) was known as the major oil fatty acid in Castor bean. The highest Ricinoleic acid was reported from Urmia region (88.94 percent) and the lowest Ricinoleic acid was recorded from Shabestar region (85.72 percent). Other fatty acids identified from various regions including linoleic acid (2.25 to 4.73 percent), palmitic acid (0.9 to 2.13 percent), oleic acid (3.05 to 4.22 percent), stearic acid (0.55 to 1.54 percent), linolenic acid (1.35 to 2.88 percent), dihydroxystearic acid (0.51 to 0.85 percent) and eicosanoic acid (0.86 percent).