Rice bran oil

About: Rice bran oil is a research topic. Over the lifetime, 2102 publications have been published within this topic receiving 32504 citations.

RESEARCH ARTICLES Hypocholesterolemic effect of physically refined rice bran oil: studies of cholesterol metabolism and early atherosclerosis in hypercholesterolemic hamsters

Abstract: Physically refined rice bran oil containing 2–4% nontriglyceride components as compared to other vegetable oils appears to be associated with lipid lowering and antiinflammatory properties in several rodent, primate and human models. These experiments were designed to investigatepossiblemechanismsfor thehypocholesterolemiceffectofthephysicallyrefinedricebranoilandtoexamineitseffectonaorticfatty streak formation. In the first experiment, 30 hamsters were fed, for 8 weeks, chow-based diets plus 0.03% added cholesterol and 5% (wt/wt) coconut, canola, or physically refined rice bran oil (COCO, CANOLA or PRBO animal groups, respectively). Both plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in PRBO but not in CANOLA relative to COCO. PRBO also showed a significant 15–17% reduction in cholesterol absorption and significant 30% increase in neutral sterol (NS) excretion with no effect on bile acid (BA) excretion. Both CANOLA and PRBO showed a significant 300–500% increase in intestinal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and significant (N25%) decrease in hepatic HMG-CoA reductase activities with respect to COCO. In a second experiment, 36 hamsters were fed chow-based diets with 0.05% added cholesterol, 10% coconut oil and 4% additional COCO, CANOLAorPRBO.RelativetoCOCOandCANOLA,plasmaTCandLDL-CweresignificantlyreducedinPRBO.Earlyatherosclerosis(fatty streak formation) was significantly reduced (48%) onlyin PRBO,relative to the other two. These results suggest that the lipid lowering foundin PRBO is associated with decreased cholesterol absorption, but not hepatic cholesterol synthesis, and that the decrease in fatty streak formation with this oil may be associated with its nontriglyceride components not present in the other two diets. D 2005 Published by Elsevier Inc.

Stabilisation of frying oils with natural antioxidative components

Abstract: Deep-fat frying is a complex, thermal chemical process that produces fried foods with desirable colour, appearance, flavour, and texture. Normally, less stable liquid oils are hydrogenated to enhance their oxidative stability for deep-fat frying purposes. However, considerable amounts of trans and positional isomer fatty acids are formed during hydrogenation, which are nutritionally undesirable. The stability of frying oils is sometimes increased by careful blending of polyunsaturated oils with more saturated oils. The natural way of improving oxidative and flavour stability of frying oils and fats is by adding natural antioxidative components and precursors present in the plant kingdom, such as 'virgin' olive oil, sesame seed oil (SSO) and rice bran oil (RBO). A variety of natural antioxidative components, present in these oils, comprise tocopherols and tocotrienols, special sterols e.g. Δ5-avenasterol and sterol esters, squalene, sesamolin, sesamol, sesaminol and related compounds, polyphenols, etc. Various antioxidative components present in SSO and RBO are largely retained in Good-Fry® Constituents (GFC), manufactured according to European patent as well as USA and worldwide patent applications pending (Silkeberg and Kochhar, 2000). Generally, palm olein, palm oil, partly hydrogenated rapeseed oil/soybean oil and/or their blends are mainly used by the frying industry for the production of a variety of snack products and pre-fried convenience foods. Several new frying oils with good oxidative stability, which do not require hydrogenation, are now commercially available on the European market, for example high-oleic sunflower seed oil stabilised with GFC. The results showed that the addition of 6% GFC to unhydrogenated rapeseed provided crisps, produced on industrial scale, with stability similar to those fried in palm olein without GFC. Shelf life of crisps fried in soybean oil, iodine value 130, was substantially increased by addition of 5% GFC. The Good-Fry® Constituents can also be added, with advantages of flavour stability of fried snacks, to oils such as palm oil or palm olein at lower levels of 2%. It is forecasted, to meet an ever-growing consumer demand of healthier' snack products, the usage of natural antioxidative components in stabilising frying oils rich in monounsaturated fatty acids (MUFAs) will grow tremendously.

Enzyme-assisted water-extraction of oil and protein from rice bran

Abstract: Enzymatic water-extraction of oil and proteins from rice bran was studied in a laboratory-scale set-up. The effects of the following enzymes – Celluclast 1.5L, hemicellulase, Pectinex Ultra SP-L, Viscozyme L, Alcalase 0.6L and papain – on oil and protein extraction yields, and the level of reducing sugars in the extract were investigated. The results showed that Alcalase was most effective in enhancing oil and protein extraction yields. Papain was found to be superior to all carbohydrase enzymes but it gave lower yields than Alcalase. Celluclast 1.5L, hemicellulase, Pectinex Ultra SP-L and Viscozyme L did not affect yields significantly but increased the level of reducing sugars in the extract. © 2002 Society of Chemical Industry