Biology:Rice bran oil
Rice bran oil is the oil extracted from the hard outer brown layer of rice called 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 the Indian subcontinent and East Asian countries, including India , Nepal, Bangladesh, Indonesia, Japan , and Malaysia.[1]
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.[1] Also present are tocopherols and tocotrienols (two types of vitamin E) and phytosterols.
- Fatty acid composition[1]
| Fatty acid | Numbering | 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% |
| Property | Crude rice bran oil | Refined oil |
|---|---|---|
| Moisture | 0.5-1.0% | 0.1-0.15% |
| Density (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 |
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 and palpanese extract, 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,[4] and in other countries as a dietary supplement.
Comparison to other vegetable oils
See also
- Cereal germ
- Bran
- Rice germ oil
- Wheat germ oil
- Wheat bran oil
- Yushō disease
References
- ↑ 1.0 1.1 1.2 Orthoefer, F. T. (2005). "Chapter 10: Rice Bran Oil". in Shahidi, F.. Bailey's Industrial Oil and Fat Products. 2 (6 ed.). John Wiley & Sons, Inc.. p. 465. ISBN 978-0-471-38552-3. https://books.google.com/books?id=wG-0QgAACAAJ. Retrieved 2012-03-01. [|permanent dead link|dead link}}]
- ↑ "What is Rice Bran Oil". A. P. Refinery. http://www.riceactive.com/?page_id=203.
- ↑ SEA HandBook. The Solvent Extractors' Association of India. 2009.
- ↑ "National Drug Standard for 谷维素片 / Oryzanol Tablets (DRAFT)". 国家食品药品监督管理总局. http://www.chp.org.cn/upload/sites/chp/resource/2014b/2015030608361130431.pdf.
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