Vegetable oils rice bran

Squalene Vegetable oil, olive oil, rice bran oil Myrtenol Myrtus cuninus... 

There are several minor oilseeds that an important because of their special characteristics, properties, nutritional and health benefits. These include high-y-linolenic oils (evening primrose, borage or starflower and blackcurrant), virgin olive oil (Chapter 9), and the seed oils from sesame, rice bran, pumpkin, hemp and melon. This chapter deals with three minor vegetable oils, namely sesame seed oil, rice bran oil, and flaxseed (linseed and linola) oil. 

Walnut oil Wheat germ oil Soya bean oil Tomato seed oil Rice bran oil Vegetables... 

Determination of tocopherols in vegetable oils Determination of tocopherols and tocotrienols in rice bran Determination of tocopherols in tomato... 

Yamazaki, N., T. Otomo, and K. Kawai. Antitumor glycoprotein extraction from rice bran. Patent-Japan Kokai Tokkyo Koho-61 143,323. 1986 9 pp. Sharma, R. D. and C. Rukmini. Hypocholesterolemic activity of unsa-ponifiable matter or rice bran oil. Indian J Med Res. 1987 3 278-281. Polasa, K., and C. Rukmini. Mutagenicity tests of cashewnut shell liquid, rice-bran oil and other vegetable oils using the Salmonella typhimurium/mC crosome system. Food Chem Toxicol 1987 25(10) 763-766. 

The commodity vegetable oils can be classified in various ways. Some are byproducts so that decisions regarding their production are largely controlled by the nonoil component. Examples are corn oil and cottonseed oil. These are byproducts of cereal and fiber production, respectively. Also, rice bran oil is a byproduct of rice production. As a consequence, oil production is not the main economic factor that influences the areas cultivated by these crops. It is sometimes argued that soybean falls into this byproduct category and that the bean is grown as a source of protein with the oil as byproduct. It is true that the bean produces only 18% of oil against 79% of residual meal rich in protein, but the value of these two commodities is evenly balanced and there are times when the demand is oil-led and other times when it is meal-led. 

Rice bran oil is used in foods, feed, and industrial applications. Only high-quahty oil is targeted to foods. The use of rice bran oil in Japan, where it is the largest volume domestically produced vegetable oil, is as a frying oil where its flavor is preferred over alternative oils. The oxidative stability of rice bran oil is equivalent to peanut oil and cottonseed oils in deep frying applications (Table 18) (8, 59). 

Carotenoids and chlorophylls are the major lipochromes of vegetable oils. Cmde regular sunflower oil is not particularly rich in carotenoids (as palm oil is) or in chlorophylls (like rice bran, rapeseed, olive, and avocado oils). This gives cmde regular sunflower oil its light-amber color, turning to pale yellow upon the bleaching operation. 

The typical compositions of crude rice bran and germ are shown in Table 20. Bran and germ oil compositions are very similar. Crude rice oil tends to contain higher levels of non-TAG components, which causes higher oil refining losses than for other vegetable oils. Physical properties of RBO are summarized in Table 21. In the United States, characteristics of quality RBO are described as maximum 0.1% FFA, maximum peroxide value 1 meq/kg, 0.05% moisture, iodine value 95-110, saponification value 180-195, and Lovibond color value of 3.5R (91). Japanese standards for refined RBO are similar to those in the United States cloud point, <15°C unsaponifiable matter, <5% saponification value, 180-195 iodine... 

Unsaponifiables Rice oil has a significantly higher concentration of unsaponifiables compared with other vegetable oils (Table 25). The bioactive components of rice bran are associated with the oil fraction (97) and concentrated in the unsaponifiable fraction of the oil (8). 

The tocopherol and tocotrienol contents of selected vegetable oils are shown in Table (7). Seed oils are mostly dominated by y- or a-tocopherol, but high levels of 5-tocopherol especially characterize soybean oil, which is the richest and commercially the most used source of tocopherols (46). Rice bran and pahn oils, on the other hand, represent the important sources of tocotrienols (45, 47). Rapeseed... 

High aliphatic alcohols and wax esters in which aliphatic alcohols or sterols are esterified to fatty or phenolic acids are also present in cmde vegetable oils at low levels and are partially removed in the winterization process during oil refining. Waxes, mainly esters of long-chain saturated fatty acids and a monounsaturated alcohol, especially eicosenoic alcohol, are found in crude vegetable oils such as olive, sunflower, soybean or peanut but are absent from com or rice bran oils... 

For identification of tocopherols and tocotrienols after chromatographic separation, pure tocopherols and tocotrienol mixtures are commercially available. Their purity can be checked by both HPLC and GC and the concentration of stock solutions by UV spectroscopy (Table 1.6). It is common to use lipid extracts from cereals and rice bran and their mixtures with pure compounds and vegetable oils to tentatively identify the vitamers and to study the performance of the HPLC separation. 

A variety of unsaturated FAs occur naturally in large quantities. These acids contain an even number of carbon atoms 18-carbon atoms containing one, two, and three double bonds occur most frequently. The most abundant monoenic acid in vegetable oils and animal fats is oleic acid (C18 1). Rich sources of C181 are olive oil (70%), peanut oil (40%), sesame oil (40%), rice bran oil (45%), Camellia oleifera tea seed oil (80%), beef tallow (40%), and lard (45%). 

Solvent extraction is used extensively to recover chemicals from natural products. Solvents are used to extract and concentrate natural oils and products in the bioprocessing industries (nutraceu-tical, food, pharmaceutical, feed, cosmetic, biotechnology) in quantities from grams to metric tons. Biotechnology applications include the recovery of primary and secondary metabolites [4]. Extraction is used to recover vegetable oils and food products. It is used to process a variety of materials including groundnut, mustard seed, soybean, pahn kemal, sunflower, rice bran, copra, cottonseed, and minor oil seeds like neem, mahua, watermelon seed, castor seed, and so on. 

One approach to increase the plQlosterol ester content of vegetable oils is via refining rather than isolating em from the by-products and then adding them back to the oil (26). Such a processing scheme simplifies the eruichment process and improves the economic feasibility of the production. Dunford and fCing (27) were able to increase the total phytosterol ester content of rice bran... 

Vegetable oils, especially the seed oils, are rich sources of tocopherols. Refining waste from the edible oil industry has emerged as an important raw material for the extraction of vitamin E, and the residues of the soybean refining industry are one such source. Tocotrienols, on the other hand, are found predominantly in palm oil and in cereals such as barley and rice bran oils. With the emergence of palm oil as the second largest edible oil in world markets, technological advances have been made to similarly extract tocotrienol-rich palm vitamin E from the refinery wastes of the industry. The resultant product, often termed palm tocotrienol-rich fraction (TRF), is currently available on a commercial scale from Malaysia. A similar tocotrienol-rich vitamin E preparation derived from rice bran oil is also available in the U.S. 

Seeds are one source of vegetable fibres, oils, and protein. Oil-bearing seeds are mechanically squeezed in a seed expeller or the oil is extracted with a solvent leaving behind the pulp and fibre syn. seed cake, oil cake, or meal. Seed cake retains some oils as does the seed expeller. Common seed cakes include cottonseed, peanut, linseed, maize, palm, rape seed, rice bran, soy beans, and sunflower. 

Comparative investigations of the rates of hydrolysis of various natural triglycerides by pancreatic lipase have been carried out by several workers (257-260), As a general rule it is found that vegetable fats, such as coconut oil, palm oil, peanut oil, and rice bran oil, are hydrolyzed more rapidly than animal fats, such as beef fat or whale oil. These studies do not shed much light on the mode of action of lipase, but tend to support the often quoted view that unsaturated fatty acids are split off more readily than saturated acids they are useful when the nutritional values of natural fats are under consideration. Castor bean lipase hydrolyzes coconut oil more rapidly than beef fat and certain other fats (261). 

The fatty acid spectrum of rice bran oil is 22-25% palmitic acid, 37-41% oleic acid and 37-41% linoleic acid. More recently, interest in rice oil escalated with its identification as a healthy oil that reduces serum cholesterol. Rice bran is a good source of antioxidants including vitamin E and oryzanol (ferulic esters of sterols and triterpene alcohols), cholesterol-lowering waxes and antitumor compounds like rice bran saccharide.Besides applications in nutrition and in phyto-chemicals, rice bran oil has traditionally been used for industrial applications, such as dimer acid manufacturing, depending on pricing for alternative vegetable oils. 

Furukawa et al. reported on a conunercial steam drying and deodorization plant to process soy sauce cakes as feedstock [27]. An agitated trough steam dryer (1.5 ton/h dry product capacity) was used. Deodorization commenced at a moisture level below 4% (dry basis) and a temperature of 135°C. The oils and fats distilling from the cake result in deodorization. Indeed, the fats and oils were used as auxiliary fuels for the process. Concurrent steam drying and deodorization of rice bran, fish meal, and pupa were also reported by Akao [28]. In these products, the odor is due to oxidation of lipids. Akao also showed that the quality of green tea and vegetables dried in steam (e.g., color, odor, etc.) was acceptable. 

A blend of high-oleic vegetable oil (com or sunflower) with up to 6% of sesame and/or rice bran oil, both of which show high oxidative stability by virtue of the antioxidants among their minor components. 

Starch is a natural product from renewable resources, produced during photosynthesis as food reserve for plants and vegetables. It is the second most abundant biomass material in nature. It is found in plant roots, stalks, and crop seeds. The most important industrial starch sources are crops such as corn, wheat, potato, tapioca and rice. By refining these crops several byproducts can be obtained such as oil, bran, gluten, dextrin, sugar (glucose, fructose, HFCS), ethanol (for beverages and bio-fuels) and starch. 

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