Rice bran oil is the oil extracted from the hard outer brown layer of rice after chaff (rice husk). It is known for its high smoke point of 232 °C (450 °F) 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 in several Asian countries, including Bangladesh, Japan, India and China.
Rice bran oil is an edible oil which is used in the preparation of vegetable ghee. Rice bran wax, obtained from rice bran oil and palpanese extract, is used as a substitute for carnauba wax in cosmetics, confectionery, shoe creams and polishing compounds.
|C14:0 Myristic acid||0.6%|
|C16:0 Palmitic acid||21.5%|
|C18:0 Stearic acid||2.9%|
|C18:1 Oleic acid (an Omega 9 fatty acid)||38.4%|
|C18:2 Linoleic acid (LA, an Omega 6 fatty acid)||34.4%|
|C18:3 α-Linolenic acid (ALA, an Omega 3 fatty acid)||2.2%|
|character||Crude Rice bran oil||Refined oil|
|Density (15-15 °C)||0.913-0.920||0.913-0.920|
|Free fatty acids||5-15%||0.15-0.2%|
A component of rice bran oil is the antioxidant γ-oryzanol, at around 2% of crude oil content. Thought to be a single compound when initially isolated, it is now known to be a mixture of steryl and other triterpenyl esters of ferulic acids. Also significant is the relatively high fractions of tocopherols and tocotrienols, together as vitamin E. Rice bran oil is also rich in other phytosterols.
Literature review shows rice bran oil and its active constituents improve blood cholesterol by reducing total plasma cholesterol and triglycerides, and increasing the proportion of HDL cholesterol. Results of an animal study[non-primary source needed] indicated a 42% decrease in total cholesterol with a 62% drop in LDL cholesterol, when researchers supplemented test subjects' diets with fractionated vitamin E obtained from rice bran oil.
One small-scale study of γ-oryzanol, a mixture of chemicals found in rice bran oil, found that 90% of the women had some form of relief from hot flashes during Menopause after taking a supplement of the purified concentrate for four to six weeks.[non-primary source needed]
The oryzanol content of the pan heated rice bran oil samples remains approximately the same even when heated at 180 ˚C for 8 hours, while a decrease in oryzanol content was reported in the case of microwave heating at the same conditions.
Rice bran might help lower cholesterol because the oil it contains has substances that might decrease cholesterol absorption and increase cholesterol elimination.[medical citation needed] One of the substances in rice bran might decrease calcium absorption. This might help reduce the formation of certain types of kidney stones.
In utero exposure to germinated brown rice and its oryzanol-rich extract attenuated high fat diet-induced insulin resistance in rats.