Oilseed Crops with Modified Fatty Acid Composition

抄録

•In considering oilseed crops with modified fatty acid composition three question have to be addressed: why is it nesessary to have oils and fats with composition different from that supplied by nature? how can such changes be accomplished? and what modified material is already available or likely to be so in the near future?
•Our increased understanding of the nutritional necessary to provide healthy food and of the physical properties required for good quality spreads or frying oils allow us to write specifications for ideal oils in terms of their fatty acid composition. However, this may not be sufficient. We may need to define triacylglyderol composition and, at the same time, to manage the minor components which also have a marked influence on shelf life and on dietary properties.
•Our desire to modify fatty acid composition is at least one century old and over that period of time a range of methods-some technological and some biological-have been developed. This lecture is confined to the consideration of producing modified seed oils by conventional seed breeding or by transgenic modification.
•Efforts have been directed particularly to changing the levels of saturated acids, oleic acid, and linolenic acid-sometimes raising these and somtimes lowering them. Thses changes have been applied to the major oilseeds-soybean, rapeseed/sanola, and sunflower - and also to linseed. However, because of inadequqte control of triacylglycerol composition, and the minor components, the new oils have not always displayed the desired properties.