Rice bran oil
| Fat composition | |
|---|---|
| Saturated fats | |
| Total saturated | 25% Myristic: 0.6% Palmitic: 21.5% Stearic: 2.9% |
| Unsaturated fats | |
| Total unsaturated | 75% |
| Monounsaturated | 38% |
| Oleic acid | 38% |
| Polyunsaturated | 37% |
| Omega-3 fatty acids | α-Linolenic: 2.2% |
| Omega-6 fatty acids | Linoleic: 34.4% |
| Properties | |
| Food energy per 100 g (3.5 oz) | 3,700 kJ (880 kcal) |
| Smoke point | 232 °C (450 °F) |
| Iodine value | 99-108 |
| Acid value | 1.2 |
| Saponification value | 180-190 |
| Unsaponifiable | 3-5 |
Rice bran oil is the oil extracted from the hard outer brown layer of rice after chaff (rice husk). It is notable for its high smoke point of 232 °C (450 °F) and its 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.[1]
Contents
Uses
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. It is an edible oil which is used in the preparation of vegetable ghee.
Composition
Rice bran oil has a composition similar to that of peanut oil, with 38% monounsaturated, 37% polyunsaturated, and 25% saturated fatty acids. The fatty acid composition is:[1]
| Fatty acid | Percentage |
|---|---|
| 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% |
Physical Propreties of Crude & refined Rice bran oil [2][3]
| character | Crude Rice bran oil | Refined oil |
| Moisture | 0.5-1.0% | 0.1-0.15% |
| Density (15-15 °C) | 0.913-0.920 | 0.913-0.920 |
| Refractive Index | 1.4672 | 1.4672 |
| Iodine value | 85-100 | 95-104 |
| Saponification value | 187 | 187 |
| Unsaponifiable matter | 4.5-5.5 | 1.8-2.5 |
| Free fatty acids | 5-15% | 0.15-0.2% |
| oryzanol | 2.0 | 1.5-1.8 |
| Tocopherol | 0.15 | 0.05 |
| Color(Tintometer) | 20Y+2.8R | 10Y+1.0R |
Health benefits
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.[1] Also significant is the relatively high fractions of tocopherols and tocotrienols, together as vitamin E. Rice bran oil is also rich in other phytosterols.
Cholesterol
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.[4] Results of an animal study[5] 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.
Menopause
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 flushes after taking a supplement of the purified concentrate for four to six weeks.[6]
Antioxidant stability
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.[7]
Omega fatty acids and inflammation
Rice bran oil has about 2% omega 3 fatty acids in it (more than olive oil), and 33% omega 6 fatty acids. Its omega 6-to-omega 3 ratio is much higher than olive oil. A high omega 6-to-omega 3 ratio can be a factor in increasing inflammation.[Citiation needed]
Rice bran oil has been tested to reduce cholesterol levels.
Calcium Absorption
Rice bran might help lower cholesterol because the oil it contains has substances that might decrease cholesterol absorption and increase cholesterol elimination. One of the substances in rice bran might decrease calcium absorption; this might help reduce the formation of certain types of kidney stones.[8]
See also
References
- ↑ 1.0 1.1 1.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://www.riceactive.com/?page_id=203
- ↑ SEA HandBook-2009,By The Solvent Extractors'Association of India
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Minhajuddin M, Beg ZH, Iqbal J. "Hypolipidemic and antioxidant properties of tocotrienol rich fraction isolated from rice bran oil in experimentally induced hyperlipidemic rats." Food and Chemical Toxicology. 2005; 43(5):747-53.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://www.webmd.com/vitamins-supplements/ingredientmono-852-rice%20bran.aspx?activeingredientid=852&activeingredientname=rice%20bran
