Palm oil fractionation

Fractionated palm oil is a solid obtained by fractionation and hydrogenation and is used as a suppository base... 

Another product manufactured by Loders-Croklaan (Unilever) and named Beta-pol consists mainly of triacylglycerols of the type UPU. This is used as a constituent of infant formulas (191). Human milkfat is unusual in that it contains a significant proportion of its palmitic acid in the sn-2 position. Although this is true also for lard (pig fat), it is not a feature of vegetable oils. Betapol is made from tripalmitin and oleic acid using the lipase from Mucor miehei to promote 1,3-acyl exchange. These materials are expensive, and in practice, fractionated palm oil, rich in tripahnitin, is reacted with acids from high-oleic sunflower or safflower or from olive oil. 

Process Description. There are three commercial methods for fractionating palm oil dry, detergent, and solvent process. 

The author is developing (mid-2004) zero trans-, no hydrogenation, no interesterification, no modification of any kind, tub and stick margarines. The formula will include specially processed soybean oil, corn oil, cottonseed oil, or mid-oleic sunflower seed oil, and double-fractionated palm oil, or double-fractionated cottonseed oil. The products are proprietary for now. 

Fat fractionation Palm oil, tallow, milk fat Size distribution for separation... 

In one example of the Unilever process described by Moore et al. (1991), lipase from Mucor miehei immobilized on celite was used in a packed-bed reactor. The feedstock consisting of equal parts of dry fractionated palm oil mid-fraction with an IV value of 55 and stearic acid was dissolved in hexane. The feedstock was percolated down a column... 

Table 12.7 Comparison of solids content of isolated fractions from products of enzymatic interesteriiication of a mixture of fractionated palm oil mid fraction (1 part) and stearic add (1 part) with cocoa butters...

Triglyceride Palm oil mid-fraction (% dry weight) Cocoa butter (% dry weight)... 

One of the main problems associated with beneficiation of the Kolwezi siliceous ore is the production of malachite and pseudomalachte slimes that have a relatively low flotation rate. Most of the copper losses occurring in the plant are in the -15 pm fraction. Experimental testwork conducted with a different palm oil emulsifier indicated that copper recovery from the fine fraction can be significantly improved with the use of petroleum sulphonate (Petrosol 845) as the emulsifier [21] for palm oil. Significant improvement in copper recovery was realized in the fine fractions with the use of palm oil emulsified with Petrosol 845. 

Traditional column chromatography has also been employed for the extraction of carotenoids from palm oil. Separations were carried out on silica columns, carotenoids were eluted with n-hexane while the free fatty acids of the oil were removed from the stationary phase with ethyl acetate. The recovery of the method was 45 per cent and the purity of the cartotenoid fraction about 20 per cent w/w [23],... 

Fractionated palm seed oil (medium-chain triglyceride)... 

Many of these ships depart for foreign ports without a cargo. For example, some of the European ships are sometimes routed to Singapore where they pick up palm oil for the trip back to Europe. However, these ships nearly always leave Western Australia with empty holds. Therefore, shipping charges out of WA for a chemical cargo would be only a fraction of that charged if a ship had to be provided for exclusive use (see Table B.9). 

The tropical oil crops, coconut and palm, are the most efficient oil-producing crops, with coconut plantations yielding up to 2 tonnes per hectare of oil and the best performing palm plantations from 5-6 tonnes per hectare. By comparison, oil yields of temperate oil crops are typically of the order of 1-2 tonnes per hectare for the best oil-yielding crops (oilseed rape and sunflower). Clearly, Table 2.1 represents only a small fraction of oil-bearing plant species. Many other seed, fruit and nut oils are extracted for food use, however unless they contain fatty acid profiles or fatty acid derivatives of specific industrial interest, total oil-yield, fatty acid yield and cost of the final oil product tends to limit their use in industrial applications on all but a small or localised scale. 

High Cl6 0 Palm oil or fraction present palm oil and palm olein is also likely to raise oleic acid, while stearin is not so likely to do so... 

Standards for named animal fats and named vegetable oils These standards were adopted formally by the CAC in 1999 (Joint FAO/WHO, 1999e). The Standard for Named Animal Fats combines and updates provisions for lard, rendered pork fat, premier jus and edible tallow. The Named Vegetable Oils Standard covers 15 different oils of particular importance in international trade and also the palm oil fractions, palm olein and palm stearin (see Table 8.5). 

The crystallization behavior of milk fat (which contains minor lipids) and a pure triacylglycerol fraction of milk fat were compared by Herrera et al. (1999). The results suggested that minor lipids delay nucleation but promote crystal growth. Other workers who examined the effects of added phospholipids on palm oil, suggested that some phospholipids delayed nucleation while others had more significant effects on the rate of growth of fat crystals (Smith, 2000),... 

Interesterification of milk fat with palm stearin, the harder fraction obtained on fractionation of palm oil, provides a possible route for the production of pastry margarine and bakery products. Milk fat by itself, unless fractionated into a hard fraction, is not very suitable in these applications because it lacks sufficient solids at high temperatures. 

Thermal fractionation technology is most developed in the palm oil industry, where most oils are fractionated before sales. Solids profiles of stearins that have been fractionated from crude palm oil by chilling to different temperatures are shown in Fig. 34.21.118 Thermal fractionation, and double fractionation can be useful tools in obtaining fat fractions with the specific desired characteristics (Fig. 34.22).119... 

Fig. 34.21. Examples of stearins separated from crude palm oil by chill fractionation. (FromTan, B. K and Flingoh, C. H. OH. "PORIM Survey 1979/80 Oleins and Stearins from Malaysian Palm Oil Chemical and Physical Characteristics," PORIMTechnol. Palm Oil Res. Inst. Malaysia, No. 4, 1981. With permission.)...

New oilseed crops, currently studied as potential sources of specialty fatty acids, include Crambe abyssinica for erucic acid, Limnanthes alba for very long-chain fatty acids, Dimorphotheca pluvialis for dimor-phecolic acid, Lesquerella fendleri for les-querolic acid, Calendula officinalis for calendic acid, and Euphorbia lagascae and various Vernonia species for vernolic acid.194 The lowest cost sources (inedible fats and oils and palm oil fractions) are likely most likely to be exhausted first as world trade in industrial applications grows. Cornstarch is becoming a major feedstock for plastics production. This may compete with potential oil uses, but also will increase production of com oil. 

Solid Fat Content of Fats and Oils by NMR (SFC) (Cd 16-81) estimates the percentage of solids in a semi-solid fat on the basis of the pulsed nuclear magnetic resonance (NMR) signal of hydrogen in the liquid fraction. The method is used in the palm oil industry and widely throughout the world. 

During processing of fats, crystallization is often used to modify the properties of the fat. For example, winterization of vegetable oils is needed to ensure that the oil remains a clear liquid even when stored at low temperatures for extended time periods. The process of fractionation of fats to produce components of natural fats with different melting properties also requires control of crystallization to optimize the separation process. Many fats, including palm oil, palm-kernel oil, milk fat, and tallow, are fractionated by crystallization to produce different functional fats. 

In this section, the polymorphic properties of natural fats are briefly discussed by highlighting miMat, cocoa butter, and palm oil fraction based on recent research into the effects of external factors on the polymorphic crystallization such as shear stress, ultrasound stimulation, and addition of food emulsifiers. 

Palmitic Acid Oils The commodity oil richest in palmitic acid is pahn oil (44%). This oil is also rich in oleic acid (37%), contains lower levels of linoleic acid (10%), and is a valuable source of minor components, especially carotenes, toco-pherols, and tocotrienols (Section 3). Palm oil is an important world commodity in feeding the developing world. It is fractionated extensively to give a wider range of uses as palm olein and palm stearin. The only other commodity oil with a significant level of palmitic acid is cottonseed oil (27%). 

Shea (Butyrospermum parkii, shea butter, karite butter). This fat comes from trees grown mainly in West Africa and contains an unusually high level of unsapo-nifiable material ( 11%), including polyisoprene hydrocarbons. It is rich in stearic acid, but its fatty acid composition varies with its geographical source. It contains palmitic (4—8%), stearic (23-58%), oleic (33-68%), and hnoleic acid (4—8%). It can be fractionated to give a stearin (POP 1%, POSt 8%, and StOSt 68%), which can be used as a cocoa butter equivalent (79, 122-124). It is one of the six permitted fats (palm oil, iUipe butter, kokum butter, sal fat, shea butter, and mango kernel fat), which, in some countries at least, can partially replace cocoa butter in chocolate (86). 

Dry fractionation is a two-step operation involving crystallization that should be allowed to proceed slowly to the equilibrium state, followed by hltration of the solid from the liquid phase. Crystallization occurs over several hours and requires good temperature control. The temperature must be lowered at a hxed rate to the selected value, and this must be combined with efficient but slow agitation. Good filtration—aiming at complete separation of solid and liquid—is important and may be carried out under reduced pressure using a Florentine hlter or under pressures up to 5 Mpa (50 bar) with a membrane hlter. Fractionation is applied mainly to palm oil but also to lauric oils (coconut and palmkemel), butter oil, beef tallow, hardened soybean, and cottonseed oil. 

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