Rice bran oil

From Wikipedia, the free encyclopedia
Jump to: navigation, search
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]

A bottle of rice bran oil, flanked by smaller bottles of sesame oil and hemp seed oil.

Uses[edit]

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[edit]

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[edit]

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[edit]

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][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.

Menopause[edit]

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 after taking a supplement of the purified concentrate for four to six weeks.[6][non-primary source needed]

Antioxidant stability[edit]

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[edit]

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.[medical citation needed]

Rice bran oil has been tested to reduce cholesterol levels.[vague][medical citation needed]

Calcium absorption[edit]

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.[8]

See also[edit]

References[edit]

  1. ^ a b c 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. Retrieved 2012-03-01. 
  2. ^ http://www.riceactive.com/?page_id=203
  3. ^ SEA HandBook-2009,By The Solvent Extractors'Association of India
  4. ^ A.F. Cicero; A. Gaddi (2001). "Rice bran oil and gamma-oryzanol in the treatment of hyperlipoproteinaemias and other conditions". Phytother Res. 15 (4): 277–286. doi:10.1002/ptr.907. PMID 11406848. Retrieved 2006-10-09. 
  5. ^ 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.
  6. ^ Ishihara, M; Ito, Y; Nakakita, T; Maehama, T; Hieda, S; Yamamoto, K; Ueno, N (1982). "gamma-oryzanol on climacteric disturbance". Nihon Sanka Fujinka Gakkai zasshi. 34 (2): 243–51. PMID 7061906. 
  7. ^ Paul, A.; Masih, D., Masih, J., Malik, P. (2012). "COMPARATIVE ANALYSIS OF HEAT DEGRADATION OF ORYZANOL IN RICE BRAN OIL, MUSTARD OIL AND SUNFLOWER OIL BY MICROWAVE AND PAN HEATING" (PDF). International Journal of Food and Nutritional Sciences. 1 (1): 110–117. Retrieved December 2012.  Check date values in: |access-date= (help)
  8. ^ http://www.webmd.com/vitamins-supplements/ingredientmono-852-rice%20bran.aspx?activeingredientid=852&activeingredientname=rice%20bran