Erucic acid content

Dealing with such problems and adopting methodologies to reduce any risk of crop contamination places additional labour, infrastructure and financial burdens on growers. To address such concerns it has been proposed that non-food crop plants unrelated to current food crops and native flora (to avoid risk of crosspollination) should be used as potential hosts for engineered industrial use traits. Crambe, (Crambe abyssinica) has been identified as a suitable model oil crop plant (EPOBIO 2007). Crambe is a plant that has already been commercialised on a relatively small scale to exploit its high erucic acid content. Elsewhere, safflower has been proposed as a potential candidate, as well as the use of algae, moss and the aquatic plant duck weed in contained bioreactor systems. 

However, the introduction of canola left unmet needs for erucic acid in industrial markets. High-erucic acid rapeseed then was imported from Northern Europe for extraction, followed by efforts to increase erucic acid contents in domestic industrial rapeseed as well as development of crambe (Crambe abyssinica) specifically for its erucic acid content. At the current state of development, equipment corrosion and poisoning of hydro-... 

Plant breeding work to raise the erucic acid content in the oil is being done in Canada and elsewhere. Indications are that the erucic acid content of about 80% is possible. This is of interest not only for some of the specialty food uses mentioned above, but also especially for industrial lubricants (See nonfood uses of HEAR oil). 

Canola oil is a refined rapeseed oil obtained from particular species of rapeseed that have been genetically selected for their low erucic acid content. In pharmaceutical formulations, canola oil is used mainly in topical preparations such as soft soaps and liniments. It is also used in cosmetics. 

Rapeseed oil has been used for a number of years in food applications as a cheap alternative to olive oil. However, there are large amounts of etude acid and glucosinolates in conventional rapeseed oil, both substances being toxic to humans and animals. Canola oil derived from genetically selected rapeseed plants that are low in erucic acid content has been developed to overcome this problem. 

JOSEFSSON, E., JONSSON, R., Studies of variation in glucosinolate content of seed of cruciferae plants, especially in material with a high erucic acid content., Z Pflanzenzucht, 1969,62,272. 

Triglycerides have not only been used as feedstocks for chemical production of bioplastics, but also the enzymatic production of polymers. Polyhydroxyalkanoates were produced by using Bras Sica carrinata oil with high erucic acid content (35-48%) as a feedstock iox Pseudomonas... 

China is the second largest producer of rapeseed in the world (Table IV). Most of their rapeseed is a winter form of Brassica napus, high in erucic acid and high in glucosinolates. There is less interest in reducing the erucic acid content of the oil than there Is in developing low glucosinolate varieties. 

The continued development of the LEAR varieties carried on by plant breeders and the experience gained by continued production made it possible by December 1, 1973, to limit the erucic acid content in processed edible food products to less than 5%. 

An erucic acid content of not more than 5% (w/w) of the component fatty acids ... 

The R-500 has an atypically high proportion of 20 1 n-7, but some other 6. campestris cultivars (cv. Polar and cv. Span) seem to have had proportions of 7 or 8% of 20 1 n-7 in total 20 1 (Hougen and Wasowicz, 1979). There may be other factors such as maturity of seed which also require investigation, as they affect fatty acid composition (Izzo et a/., 1979) or distribution (Harris and Norton, 1979), but it seems that the LEAR varieties wih a low erucic acid content have Cig, C20 and C22 monoethylenic fatty acids dominated by the "n-9" isomers, with 4-6% of monoethylenic "n-7" acid in the Cie chain length, and lesser proportions in the C20 and C22 chain lengths. These n-7 isomer details are similar to the scanty information available for other vegetable oils. 

Fatty Acid Composition of Canadian Rapeseed Oils with High and Low Erucic Acid Content... 

The magnitude of the variation in the composition of rapeseed oil and meal now commercially available has created a need for new terms to describe the products derived from rapeseed. The fatty acid composition of most edible vegetable oils such as soybean, sunflower, or cottonseed oils, varies within narrow limits. Thus, the species or commodity name (e.g., soybean oil) provides a reasonable description of the fatty add composition of soybean oil. In contrast, the erucic acid content of commercially available rapeseed oil may vary from near zero to 55%, and the oleic acid from 10 to more than 60%. A number of terms have been proposed or utilized to describe the new rapeseed oil whose fatty acid composition has been altered by the elimination of erucic acid these include low erucic acid rape-seed oil (LEAR), canbra, and canola. Similar terms such as high erucic acid rapeseed oil (HEAR) and common or traditional rapeseed oil have been used to describe rapeseed oil whose fatty acid composition includes substantial amounts of erucic acid. 

After the rape cultivar. Tower, which produces seed oil very low in erucic acid content and seed low in glucosinolate content was released in 1974,... 

The frequency of genes for the absence of erucic acid in rape, turnip rape, and other closely related species appears to be very low. If seed oils low in erucic acid content were available within leaf mustard (Brassica juncea) this species, now grown for edible oil in India and China, could become an edible oil crop in other countries. Efforts to find genes for the absence of erucic acid in this species have been under way for a number of years in several countries, and individual plants from 8. juncea which produce seed oils essentially free from erucic acid have been isolated recently (Kirk and Oram, 1981). 

The erucic acid content is largely controlled by the genotype of the developing seed rather than by the genotype of the maternal plant (Downey and Harvey, 1963 Harvey and Downey, 1964 Stefansson and Hougen, 1964 Kondra and Stefansson, 1965). For this reason, a technique could be developed whereby one cotyledon or a part of one cotyledon could be used as a sample for fatty acid analysis, while the remainder of the seed could be used to produce a plant (Downey and Harvey, 1963). This technique is useful in breeding and can also be used to facilitate genetic studies, since the seeds on an Fi plant represent the F2 population. 

Due to the large variation in erucic acid content (0.1-60%) in the seed oils from rape and turnip rape, the separation of genetically controlled variation of erucic acid from environmental variation was relatively easy. The invariable association of substantial amounts of eicosenoic acid (e.g. 6%) with an allele for the presence of erucic acid which might condition the production of a low level of erucic acid (e.g., less than 2%) ensured selection of the genetically lowest level of erucic acid. 

B. Surveys of the Erucic Acid Content of Rapeseed Grown in... 

In 1970, when the decision was made to convert to LEAR, only one variety of rapeseed was available which had low levels of erucic acid. Oro rape-seed, a B. napus variety had been released in 1968 by the Agriculture Canada Research Station at Saskatoon but was not grown widely because of its relatively low yielding ability. Fortunately, the breeding programs at both Saskatoon and the University of Manitoba had lines available with low erucic acid contents and in 1971 the varieties Zephyr and Span were introduced. These two varieties were replaced by Midas and Torch in 1973. 

Craig et a/, (1973) found that the erucic acid content of rapeseed increased by 0.5% as the seed was grown from isolation in California to commercial production in Western Canada. Most of this increase was thought to be due to the presence of volunteer high erucic acid plants contaminating the low erucic acid fields although some increases in erucic acid due to cross-pollination and environment were noted. Wild mustard [Brassica /caber (DC) L. C. Wheeler cv. pinnatifida (Stokes) L. C. Wheeler] has also been implicated in adding to the erucic acid content of rapeseed. Studies on the erucic acid content of wild mustard found in Canadian rapeseed have... 

The first 8. campestris LEAR varieties had erucic acid contents on the order of 3.5% as breeder s seed. This level was sufficiently close to 5% to provide serious problems when the seed was grown commercially. Both LEAR cv. Span and cv. Torch were reselected after release to provide seed with significantly lower levels of erucic acid. 

Although increases in the erucic acid content of pedigreed seed may be predicted and documented, the major cause of increases in erucic acid in rapeseed crops has been the use of nonpedigreed seed. Nonpedigreed seed stock often contained large amounts of volunteer material which in the early 1970s was of high erucic acid seed. 

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