CHARACTERISTICS AND FATTY ACID CONTENT OF OILS of SOME SEEDS OF MALVACEAE

The fatty components of several seeds belonging to family malvaceae were studied. Three seed varieties of okra (Hibiscus esculentas var. Pusa Swani, Baladi and Romi), Roselle seeds (Hibiscus Sabdariffa), Egyptian Mallow seeds (Malva Parviflora) and Cottonseeds (Gossypium Barbadense var. Giza 75) were investigated for their oil contents, physico-chemical properties of oils, fatty acid composition, cyclopropeniod fatty acids, phospholipids, gossypol and unsaponifiable matter constituents. The results indicated that oil content ranged from 1 5.3% for okra seed (var. Pusa) to 21.5% for roselle seed. The fatty acid profiles are generally consistent with the fatty acid pattern found in cottonseed oil but with a wide range of prortions. The main fatty acids were palmitic (15.27 - 34.33%), oleic (21.86 -38.27%) and linoleic (23.63 - 49.75%). Differences were observed in oleic/linoleic ratio. All the oils gave red colours with Halphen reagent(indication of cyclopropenoed). The unsaponifiable matter of the studied seed oils varied from 0.98 to 1.16%. The hydrocarbons fraction constituted from 8.05% (roselle seed oil) to 25.33% (okra seed oil va. Pusa) of the unsaponifiable matters. Squalene compound was the major hydrocabon (2.82 - 10.96%). The sterol fraction constituted the major component in the unsaponifiables of all oil samples. B-sitosterol was found to be predominant (65.23 - 84.02%). Crude cottonseed oil was more resistant to oxidation deterioration due to the presence of gossypol which act as natural antioxidant and also the synergistic effect of phospholipids. Because of the allied refined colour, the absence of gossypol, the reduced level of cyclopropenoid fatty acids beside the highly C18 unsaturated fatty acid contents, the results suggest that okra seed oil could be considered as a new additive source for vegetable oil.