Extraction of edible oils

The model I is very simple, and it is not very sensitive to the physical properties of the bed, but the values of the overall mass transfer coefficients optimised are strongly dependent from the equilibrium relation assumed and it only is able to describe the initial part of the extraction. Ke was determined by mass balance assuming a uniform distribution in solid bed. Ke values of 0.5, 0.2, and 0.6 were obtained for 7, 10 and 15 MPa. Assuming a = 3000 nAn", the mass transfer coefficients calculated with model I are of some orders of magnitude lower than those for external mass transfer coefficients. This type of models have being applied with success to the extraction of edible oils from seeds were the solute is in a... 

The aqueous extraction of edible oils from oilseeds works better when enzymes are used to hydrolyze struc-... 

Soluble material is leached from a slurry of porous spherical particles by suspending them in a well-stirred liquid solvent of constant volume. This type of operation finds frequent use in the leaching of ores, and in the extraction of edible oils from seeds. Show that the model for this system is made up of a single PDE for the spheres and an ODE for the stirred tank. What are the relevant boundary and initial conditions ... 

Oil palm is a tree whose fruits are used for the extraction of edible oil. It originated from West Africa, cultivated in all tropical areas of the world and has become one of the main industrial crops (Kelly-Yong et al., 2007). Additionally, the oil palms Elaeis) comprise two species of the Arecaceae, or palm family. The African oil palm Elaeis guineensis is native to west Africa, occurring between Angola and Gambia, while the American oil palm Elaeis oleifera is... 

Carrot oil—The Hquid or the soHd portion of the mixture, or the mixture itself obtained by the hexane extraction of edible carrots (Daucus carota L.) with subsequent removal of the hexane by vacuum distillation. The resultant mixture of soHd and Hquid extractives consists chiefly of oils, fats, waxes, and carotenoids naturally occurring in carrots. 

Procedures for isolation and measurement of lipids in foods include exhaustive Soxhlet extraction with hexane or petroleum ether (AOAC, 1995 see Basic Protocol 1), chloro-form/methanol (Hanson and Olley, 1963 Ambrose, 1969), chloroform/methanol/water (Folch et al., 1957 Bligh and Dyer, 1959 see Basic Protocol 2 and Alternate Protocol 2), acid digestion followed by extraction (see Basic Protocol 4), or, for starchy material, extraction with n-propanol-water (e.g., Vasanthan and Hoover, 1992 see Basic Protocol 3). Each method has its own advantages and disadvantages and successful measurement of lipid content is often dictated by the type of sample and extraction medium employed. Commercial extraction and preparation of edible oils are explained in the literature (Williams, 1997). 

Moyler, D.A., Bowing, R.M. and Stevens, M.A. (1994) C02 extraction of essential oils. PartV. Nutmeg and mace oils. In Charalambous, C. (ed.) Spices, Herbs and Edible Fungi. Elsevier Science, B.V., Amsterdam, pp. 145-170. 

Figure 4.4 Essential steps in the extracting and refining of edible oil from oilseeds.

Bulk storage and handling facilities are needed by (1) extraction plants and refineries, (2) industrial users of fats and oils, and (3) tank farm operations. The latter represent a distinct type of facility because they are not involved in the manufacture or use of edible oil products but merely store, handle, and ship them for national and international trade. 

One of the key applications of SFE-FTIR is the extraction and on-line determination of hydrocarbons. Worth special note in this context are the determinations of n-tetra-cosane in Celite (limit of deteetion 74 ng) [126] and petroleum hydrocarbons (TPH) in soils (limit of detection 1.6 ppm), as well as the characterization of edible oils in foods by correlation of the fat vinylic C-H band intensity with the iodine number [108]. 

Ueda, T. and Igarashi, O. 1987b. New Solvents System for Extraction of Tocopherols from Biological Specimens for HPLC Determination and the Evaluation of 2,2,5,7,8-Pentamethyl-6-Chromanol as an Internal Standard. J. Micronutr. Anal. 3 185-198. Van Niekerk, P.J. and Burger, A.E.C. 1985. The Estimation of the Composition of Edible Oil Mixtures. J. Am. Oil Chem. Soc. 62 531-538. 

Sayre, R.N., Nayyar, D.K. and Saunders, R.M. (1985) Extraction and refining of edible oil from extrusion-stabilised rice bran. J. Am Oil Chem. Soc., 62, 1040-1043. 

Soybeans are an important source of edible oil, but many have argued that soybean is actually a protein crop because 60-70% of the returns in processing soybeans is due to the sale of meal (Table 11.1). No other oilseed contains as much protein. Thus, processes used to extract soybean oil are designed to maximize meal quality for use in livestock feeds. 

Most lecithins obtained during degumming of edible oils are not suitable for human consumption. Therefore, they are added back to the extracted oilseed meal and used as feed. Only soybean lecithin is snitable for human and industrial uses. Properties required for soybean lecithin are shown in Table 5.4 (adapted after Precise, 1985). The phospholipid fraction of soybean lecithin contains about 30 to 32% phosphatidylcholine, 22 to 28% phosphatidylethanolamine, 18 to 20% phosphatidyUnositol, 3 to 4% phosphatidylserine, and 20 to 29% other snbstances. The fatty acid composition of soybean lecithin is shown in Table 5.5. The technical soybean lecithin obtained by extraction with a hydrocarbon solvent is very different from the phospholipid fraction obtained by extraction with chloroform-methanol (after Folch). 

Europe is the major rapeseed producing area in the world. Rapeseed production increased three- to fourfold after World War II to alleviate the severe shortage of edible oils and to lessen their dependence on imported soybeans. This development has been highly beneficial in terms of a better balanced agriculture especially in Northern Europe. Most European production is of winter rape varieties which give higher yields (Table III), and modern oil extraction techniques ensure that oil yields from the seed are also high. Yield of oil from one hectare in Europe equals that from about 4 hectares in India. 

Liquid paraffinic hydrocarbon containing seven carbon atoms in the molecule, which may be straight-chain (normal) or branched-chain (iso). Heptane can be used in place of hexane where a less volatile solvent is desired, as in the manufacture of certain adhesives and lacquers, and in extraction of edible and commercial oils. Heptane is blended with isooctane to create a standard reference fuel in laboratory determinations of octane number. 

The further processing of edible oils after extraction from the raw material is concerned with purification, or refining, and modification. The refining treatment is needed to remove, or reduce as far as is possible, those contaminants of the crude oil which will adversely affect the quality of the end product and the efficient operation of the modification processes. Certain non-glyceride compounds in the crude oil, notably the tocopherols and tocotrienols as antioxidants, have a beneficial effect on product quality and therefore the refining treatment should be designed to retain as much as possible of these compounds in the oil. 

Paraffins are isolated from the sample matrix (edible oils or food extracts often containing much fat or oil) and separated from aromatics and olefins (e.g., sterenes from the raffination of edible oils) by NPLC. As it is difficult to maintain a high activity of silica gel to separate paraffins from olefins when large amounts of matrix material are injected, two columns are used up to 30 mg edible oil or fat is injected onto a first column of 25 cm x 2 mm i.d. The hydrocarbons are transferred to a second column of the same dimension. The first column is backflushed with dichloromethane to remove the oil and other materials of the food extract. The second column only comes in contact with pentane as the mobile phase and nonpolar sample components, i.e. it maintains its high retention power for unsaturated components. Transfer of the fraction of about 400 pi volume to GC mostly involves the retention gap... 

Solvent extraction has been used in food and feedstock applications for many years, for example in the recovery of edible oil from oilseeds (Norris, 1982). 

Applications of the technique in the food industry include decaffeination of coffee, flavour extraction from hops, extraction of spice oils, and separation of glycerides from edible oils and fats (Logsdail, 1983). 

Utilization of a processing plant, it would be necessary to be able to process multiple varieties such as cherry, plum, peach, apple, etc. It is essential that the cost of by-product remain reasonable once a successful recovery operation has been established. Most of the data reported here are for oil samples prepared under laboratory conditions. The extracting solvent used for the oil recovery was usually n-hexane, which is acceptable for edible purposes. Chlorinated solvents are unacceptable for the recovery of edible oils because they may contain chlorinated components such as tetrachloroethane which is not removable by heat treatment and which if present would make the oil too toxic to be consumed. Often oils that are recovered from by-products have properties that make them desirable in cosmetics and in medical preparations. Such specialized application may command a premium price. 

Heavy fraction no plastic fragments were visible. After drying and chloroform extraction of the whole fraction, the FTIR analysis showed the fingerprint of edible oils and no peaks associated with biodegradable polyesters. 

Table 2.8 Suggested applications of dense gas extraction with CO2 in the production and fractionation of edible oils, fats and waxes...

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