Pengaruh Cara Pemanasan terhadap Kandungan Oryzanol dan Komposisi Asam Lemak Bekatul Beberapa Varietas Padi Unggul dan Padi Lokal

Rice bran oil, oryzanol and fatty acid composition of two superior rice cultivars (IR-64 and Cisadane) and two local rice cultivars (Rajalele and Merning) were studied. Rice bran were added with water (100 : 60 w/v) and mixed well to become a semisolid mass. The rice brans were heated in a microwave oven for 5 min or steamed for 15 min. They were extruded and heated in a oven at 40-50 °C until dry and the oil were extracted with hexane. Changes of oryzanol content and fatty acid composition of the rice oil after heating were investigated.
It was found that the rice bran of Cisadane and Rajalele contain a higher fat and oryzanol than IR-64 and Merning cultivars. Heating of rice bran in microwave oven or steaming decrease the oil content of rice bran and the oryzanol content of the oil. Oleic, linoleic and palmitic acid are the predominant fatty acids of rice bran oil of all cultivars. The conten of these fatty acids are 34-44%, 37-45% and 15-19%, respectively. Heating of the rice bran (steaming and microwave cooking) have a little effect on the fatty acid profile of rice bran oil, i.e. decrease the oleat and linoleat content.