Rice bran oil is the oil extracted from the hard outer brown layer of rice called bran. It is known for its high smoke point of and mild flavor, making it suitable for high-temperature cooking methods such as stir frying and deep frying. It is popular as a cooking oil across East Asia, South Asia, and Southeast Asia, including India, Nepal, Bangladesh, Indonesia, Japan, Southern China and Malaysia.
Composition and properties Rice bran oil has a composition similar to that of peanut oil, with 38% monounsaturated, 37% polyunsaturated, and 25% saturated fatty acids.
A component of rice bran oil is the γ-oryzanol, at around 2% of crude oil content. Thought to be a single compound when initially isolated, γ-oryzanol is now known to be a mixture of steryl and other triterpenyl esters of ferulic acids. Also present are tocopherols and tocotrienols (two types of vitamin E) and phytosterols.
Fatty acid composition
Fatty acid Lipidnumber Percentage Myristic acid C14:0 0.6% Palmitic acid C16:0 21.5% Stearic acid C18:0 2.9% Oleic acid (an omega-9 fatty acid) C18:1 38.4% Linoleic acid (LA, an omega-6 fatty acid) C18:2 34.4% α-Linolenic acid (ALA, an omega-3 fatty acid) C18:3 2.2%
Physical properties of crude and refined rice bran oil
PropertyCrude rice bran oilRefined oilMoisture0.5–1.0%0.1–0.15%Density (15 °C)0.913–0.9200.913–0.920Refractive index1.46721.4672Iodine value85–10095–104Saponification value187 187Unsaponifiable matter4.5–5.51.8–2.5Free fatty acids5–15%0.15–0.2%Oryzanol2.01.5–1.8Tocopherol0.150.05Color (tintometer)20Y+2.8R10Y+1.0R
Research
Rice bran oil consumption has been found to significantly decrease total cholesterol (TC), LDL-C and triglyceride (TG) levels.
Uses Rice bran oil is an edible oil which is used in various forms of food preparation. It is also the basis of some vegetable ghee. Rice bran wax, obtained from rice bran oil, is used as a substitute for carnauba wax in cosmetics, confectionery, shoe creams, and polishing compounds.
Isolated γ-oryzanol from rice bran oil is available in China as an over-the-counter drug, and in other countries as a dietary supplement. There is no meaningful evidence supporting its efficacy for treating any medical condition.
Comparison to other vegetable oils
See also Cereal germ Bran Rice germ oil Wheat germ oil Wheat bran oil Yushō disease
References