Rapeseed, genetically modified

Attempts are being made to develop oils of various cuphea species rich in one or the other of the Cg to C14 acids. (Section 6). Genetically modified rapeseed oil with lauric acid is also available but has not yet proved to be economically viable (28-30). 

Oils from genetically modified rapeseed/canola with a wide range of fatty acid compositions contained 478-677 pg/g of total tocopherols, of which >50% was y- and about 30% was a-tocopherol. There was no relationship between the fatty acid and tocopherol compositions (Abidi et al., 1999). Genetically modified canola oils had similar tocopherol compositions with a range of 504-687 pg/g of total tocopherols (Dolde et al., 1999). 

The most widely planted genetically modified food crops are soybeans, corn, rapeseed (the source of canola oil), and cotton. The percentages of these crops that were transgenic in 2002 were as follows ... 

There are several reports of plants such as rapeseed/canola being genetically modified to produce GLA but commercial products are not yet available. One example cited by Palombo et al. (2000) has the fatty acid composition detailed in Table 5. Another group (Liu et al, 2001) introduced A -desaturase and A -desaturase, both from the fungus Mortierella alpina, into canola plant cells. The modified canola plants produced an oil rich in GLA (Table 5). The major triacylglycerols in this modified oil were GGL (23 mol%), GLO (20 mol%), GGO (12 mol%), GGG (11 mol%), and GLL (8 mol%), where G represents GLA, L represents linoleic acid, O represents oleic acid, and the symbols indicate all 6 possible stereoisomers with the indicated fatty acid composition. 

Sourcing of identity preserved (IP) non-GMO (genetically modified organism) soya lecithin for the European food market has changed drastically the lecithin world market supply system since 1996. Traditional non-GMO soya beans availability wiU become scarcer, which presents a market opportunity for high-quality IP soya, sunflower and rapeseed lecithins. 

There is much controversy, at least in Europe, concerning genetic modification of plants. The three major crops affected so far are maize, soyabean and rapeseed. All of these, in addition to their other uses, are sources of oil. The reasons for modification in all these cases are related to herbicide tolerance and resistance to insects. For the varieties generally available at present, there is no known difference from non-modified strains with respect to fatty acid composition, oil yield, tocopherol level, or the level of any other minor oil constituent. 

Monola, contains about 78% oleic acid (Section 4.2.4). Efforts to modify rapeseed oil by conventional breeding and by genetic engineering are detailed in Sections 9.3 and 9.4 (44). 

Finally, genes required for particular aspects of fatty acid and triacylglycerol biosynthesis can be identified in appropriate sources, cloned, and transferred to other plants. Rapeseed has proved to be particularly flexible in this respect, and its fatty acid composition has been modified in several ways, some of which have now reached or are very close to commercial application (Section 9.4). Genetic modification procedures are also applied to soybean and other oilseed crops. 

Genetic modification of rapeseed to produce a high-stearate oil using antisense technology to reduce expression of stearoyl-ACP desaturase was reported in 1992 by Knutzon et al. When tested in the field, lines from the first modified plants showed stearate contents between 20 and 30% with total saturates slightly above 30%. Seed yield and germination under standard conditions were normal. 

As shown in Table 1, rapeseed/canola, sunflower, soybean, and safflower can all be modified by traditional breeding methods or by genetic modification to produce high-oleic varieties containing >70-90% oleic acid. The content of saturated acids is generally <10% and is lowest in the modified canola oils. 

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