Physicochemical Characterization of Rice (Oryza sativa) Bran Oil from Some Egyptian Rice Varieties

Abstract

In view of growing demand on vegetable oils in Egypt. Find a new edible oil sources from non-traditional oil crops has a great interest. The present investigation was aimed to characterize rice bran oil from three Egyptian rice varieties, namely Sakha 106, Giza 178 and Egyptian Yasmine. The crude oil content ranged from15.75 to 21.42%. Physicochemical parameters of the hexane-extracted crude rice bran oils were found to be as follow: specific gravity (30oC) (0.8163 - 0.8590), photometric colour index (2.6- 3.96), moisture and volatile matters contents (1.90 - 6.92), saponification value (172.01- 181.21 mg KOH/g), acid value (3.80 - 5.59 mg of KOH/g), free fatty acids% (1.9 - 2.81 %), ester value (168.20- 175.41 mg of KOH/g), peroxide value (0.99 - 5.55 meq/Kg), p-anisidine value (5.90 - 13.63) and totox value (15.10 - 22.90). Furthermore rice bran oil of selected varieties possesses simple fatty acid profile with three fatty acids namely oleic, palmitic and linoleic acids present more than 90% of the fatty acids. Also, rice bran oil of selected varieties was found to contain unsaponifiable matter 3.35 - 4.57%, wax 3.00 - 3.41% and gamma- oryzanol 1.59 - 3.65 gm/100 gm oil. In general, rice bran oil has several physiochemical, compositional and nutritional properties similar to those of traditional vegetable oils; which allow using rice bran oil as an important ingredient of human diet. In addition, the high level of natural antioxidants especially gamma- oryzanol improves the oxidative stability of rice bran oil.