09.12.2012 Views

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Table 1 Average Annual Production (million metric tonnes) of 17 Commodity Oils Over<br />

Selected 5-Year Periods Along with Future Projections a<br />

1976/80 86/90 96/00 06/10 16/20<br />

17 oils <strong>and</strong> fats 52.6 75.7 103.4 139.4 175.8<br />

Soybean 11.2 15.3 22.8 30.4 37.1<br />

Palm 3.7 9.2 17.9 29.2 40.8<br />

Rapeseed 3.0 7.5 12.6 17.5 22.2<br />

Sunflower 4.2 7.2 9.1 12.5 16.6<br />

Lauric oils (2) 3.3 4.3 5.4 7.5 9.6<br />

Other veg oils (7) 10.0 12.3 14.9 18.0 21.6<br />

Animal fats (4) 17.2 19.9 20.7 24.3 27.9<br />

a<br />

These figures are taken from Oil World 2020 (1). Averages of 5-year periods are taken to avoid unusually<br />

high or low figures such as occur in some years<br />

Lauric oils: palm kernel <strong>and</strong> coconut; other vegetable oils: cottonseed, groundnut, sesame, corn, olive,<br />

linseed, <strong>and</strong> castor; animal fats: butter, lard, tallow, <strong>and</strong> fish oil.<br />

B. Fatty Acid Composition of Major Oils<br />

Palmitic (16:0), oleic (18:1), <strong>and</strong> linoleic acids (18:2) are the dominant fatty acids<br />

in vegetable oils, <strong>and</strong> many oils <strong>and</strong> fats differ only in the relative proportion of<br />

these three acids. However, other fatty acids do exist <strong>and</strong> may be important. Stearic<br />

acid (18:0) is a minor component in virtually all oils; linolenic acid (18:3) becomes<br />

important in some; <strong>and</strong> the so-called lauric oils are rich in lauric (12:0) <strong>and</strong> myristic<br />

acids (14:0) (Table 3). Of the processes listed in Table 2 it is important to note that<br />

blending <strong>and</strong> fractionation lead to changes in the proportions of fatty acids. Interesterification<br />

does not change fatty acid composition but modifies the ways in which<br />

these are incorporated into triacylglycerols. However, (partial) hydrogenation results<br />

in the formation of novel fatty acids with structures different from those present in<br />

Table 2 Methods Employed to Extend the Usefulness <strong>and</strong> Improve the Properties of<br />

Natural Oils<br />

Blending Mixing of two or more oils<br />

Fractionation Separation of oils into two or more fractions<br />

Partial hydrogenation Saturation of some double bonds accompanied by<br />

double-bond isomerization<br />

Interesterification with chemical Reorganization of fatty acids among triacylglycerol<br />

or enzymatic catalyst<br />

molecules<br />

Domestication of wild crops Conversion of wild crops to crops that can be cultivated<br />

commercially<br />

Seed breeding by traditional Interspecies crossing using irradiation or mutagenesis<br />

methods<br />

if necessary<br />

Seed breeding by genetic<br />

modification<br />

Crossing between species<br />

<strong>Lipids</strong> from microorganisms Production under fermentation conditions<br />

Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!