出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/09/24 21:42:30」(JST)
Fat composition | |
---|---|
Saturated fats | |
Total saturated | 25% Myristic: 0.6% |
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]
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.
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 | 95-100 | 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 |
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.
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.
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]
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]
Squalene is a compound present in Rice Bran Oil which is easily absorbed by the skin and keeps it soft, supple and smooth.[8]
It is rich in Vitamin E which is powerful antioxidant and has antimutagenic properties which prevent from cancer. Vitamin E also helps in boosting your immunity.[8]
Rice bran oil has more than 2% omega 3 fatty acids in it (more than olive oil) and a good amount of omega 6 too.
Rice bran oil has been tested to reduce cholesterol levels.
Rice Bran oil is anti-inflammatory too and some studies have shown that its consumption can reduce the effects of menopause like hot flashes[8]
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.[9]
Rice Bran Oil is the healthiest oil according to the recommended most fatty acid levels by Indian Council of Medical Research .[8]
The National Institute of Nutrition and The Indian Council of Medical Research recommend oils that have an equal proportion of saturated fatty acids, monounsaturated fats and polyunsaturated fats. Rice bran oil has an almost balanced fatty acid composition that is close to this ratio. Rice bran oil is rich in monounsaturated and polyunsaturated fats and free of trans-fats.
A human clinical study was conducted by scientists of National Institute of Nutrition, Indian Council of Medical Research to prove hypolipidemic effect of RBO. They studied this on 12 hyperlipidemic patients, Subjects were told to replace their usual oil (any oil used previously) with Rice Bran oil. A significant decrease in bad cholesterol was noticed after period of 15 days in all 12.[10]
National Institute of Nutrition (The Apex body of Nutrition in India) in its Dietary guidelines for year 2011 has mentioned that Oryzanol found in Rice Bran Oil is helpful in reducing cholesterol and oxidative damage due to ageing, inflammation which occur in chronic diseases.[11]
It is not just the MUFA: PUFA ratio that is important but the ratio of SFA: MUFA: PUFA that is important. And according to the latest recommendations by National Institute of Nutrition (NIN) and Indian Council of Medical Research (ICMR)the ideal fatty acid composition is 27-33% : 33-40% : 27-33%. And the fatty acid composition of Rice bran oil comes closest to these recommendations with the percentages at 24: 42: 34.” The SFA: MUFA: PUFA ratios of various oils were discussed and it concluded with the fact that Rice Bran Oil indeed has the most ideal fat composition, better frying stability and offers unique health benefits due to phytosterols present in it.[12]
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リンク元 | 「オリザノール」 |
拡張検索 | 「gamma-oryzanol」 |
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