Fatty acids, metal composition and physico-chemical parameters of Igbemo Ekiti rice bran oil

Abstract

Rice bran was digested for metal analysis while the oil extracted from the bran was analysed for metal and fatty acid profile. Using cold and hot extraction methods, the oil contains high levels of unsaturated fatty acid (oleic acid: 52.10 and 34.8%), (linoleic acid: 22.1 and 27.1%) for the cold and hot extractions, respectively. Major saturated fatty acids present include palmitic acid (16.2, 14.9%) and myristic acid (ND, 1.9). The metal composition of the crude rice bran appeared higher but not statistically significant at 95% confidence interval compared with that of the rice bran oil. Cu was 36 times > CODEX range of 0.1- 0.4 ppm in the oil and the concentration of Fe in the oil was 61.28 ppm. The peroxide value (31 meqO2/kg) and the Iodine value (72 g I2/ 100 g oil), were found while the saponification value (156 mgKOH/g) and the refractive index value (1.39) obtained for the rice bran oil are within the range reported for the oil in literature. The high unsaturated and essential fatty acids in the oil implies that it has potential for cooking and industrial use if refined to reduce the Fe and Cu overload, and could be an alternative to palm oil. Key words: Rice bran, rice bran oil, fatty acids, heavy metals, physico-chemical parameters.