Vegetable oils deodorizer distillate

Clark, J.P. and Frandsen, S.S. (1998) Phytochemicals from vegetable oil deodorizer distillate, in Proc. World Conf. Oilseed Edible Oils Process (eds S.S. Koseoglu, K.C. Rhee and R.F. Wilson), AOCS Press, Champaign, IL., Vol 1, pp. 135-138. 

King JW, Dunford NT. 2001. Phytosterol-Eniiched Triglyceride Fractions from Vegetable Oil Deodorizer Distillates Utilizing Supercritical Fluid Fractionation Technology. Separation Science and Technology 37(2) 451-462. 

Deodorization There are no major differences between deodorization procedures for sunflower oil and other vegetable oils. The loss of tocopherols in the oil is worth noting for sunflower oil, though. The average tocopherol content of sunflower oil is medium (440-1520 ppm, according to Codex-Stan 210-1999), nearly all of which is alpha-tocopherol (403-935 ppm). Table 18 shows the reduction in the tocopherol content upon deodorization of sunflower oil (69). Tocopherols may be recovered from the distillate of deodorization. 

Phytosterols are industrially isolated from the distillates, resulting from the deodorization of vegetable oils (1, 34—36). Phytosterols are sometimes hydrogenated to produce phytostanols (37). As the solubility of sterols and stanols is very low (< 1% at 25°C), it limits their application in food products. Esterification of sterol and stanols is, therefore, performed to make them fat-soluble and easy to incorporate in food products (37, 38). Two margarines containing 8-9% sterols (Becel Proactiv of Unilever) or stanols (Benecol of Raisio), in the form of esters, are now available in the markets in Europe and the United States. 

Deodorizer distillate is the material collected from the steam distillation of vegetable oils, as it occurs in the process of deodorization or physical refining (103). The material has a sludgelike appearance and consistency so is often referred to as scum or scum oil. 

With the increasing interest in natural source antioxidants, such as tocopherols, and the use of both stigmasterol and (3-sitosterol as raw materials for the production of progesterone and esterone by the pharmaceutical industry, it is likely that deodorizer distillates will continue to be an important by-product for some vegetable oil processors. 

Supercritical fractionation of a liquid lipid feed material is usually carried out in a packed column. Standard columns are not available commercially and have to be custom built either in-house or by manufacturers of extraction units. Lab-scale and pilot-scale supercritical columns, 0.6-13.6 m high with internal diameters of 14.3-68 mm are available in research labs around the world and have been used for the processing of deodorizer distillates (56, 57, 86-90), vegetable and fish oils (91-105), cocoa butter, and milkfat (106-109). A schematic diagram of a typical SCCO2 fractionation column (2.8 m, 2.54 cm o.d.), which was designed and built... 

The richest sources of vitamin E in the diet are vegetable oils. a-Tocopherol is the major contributor to the total vitamin E activity in some oils, but others contain substantial amounts of y-tocopherol (Figure 6.5). Typically, wheat germ, sunflower, cottonseed, and safflower oils contain about 1700, 500, 400, and 350 mg of a-tocopherol equivalent kg-1, respectively. Tocopherols are concentrated in deodorizer distillate (DOD) during the deodorization step. As a result, DOD is a good source of natural tocopherols that are used to make natural vitamin E. DOD is composed of FAs, mixed mono-, di-, or triacylglycerols, sterols, tocopherols, sterol esters, hydrocarbons, and oxidation by-products. DOD is frequently collected and sold. A... 

About one tenth of the total amount of vitamin E produced is semi-synthetic, isomerically pure (2R,4 K,8 R)-a-tocopherol (RRR-3) which is used almost exclusively in human applications (mainly pharma). This product, originating from natural sources, is obtained from soya deodorizer distillates (SDD). Vegetable oils refined on a large scale are the major sources of vitamin E compounds [26-28]. The deodorizer distillate, originally a waste stream, contains considerable amounts (up to 10%) of a-, [I-, y- and b-tocopherols (RRR-3 to RRR-6) which are isolated by several separation methods. To increase the value of the vitamin E concentrate of mixed tocopherols obtained from SDD, the lower (I-, y- and d-homologues (RRR-4 to RRR-6, content ca. 90%) have to be transformed subsequently into the biologically more active a-tocopherol (RRR-3, only ca. 5% in the original mixture) by permethylation reactions. Permethylations are performed by chloro-, amino-, or hydroxymethylation reactions to provide functionalized alkylated intermediates, which are reductively converted into RRR-3 (Fig. 3) [29]. 

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