Crambe seed oil

By way of a specific example let us consider erucic acid. The main commercial source of erucic acid is a specially bred form of rape seed (HEAR) as pointed out above. With European consumption being around 60 000 tpa almost 40 000 ha of land are used to grow rapeseed for erucic acid production in Europe. The high level of erucic found in this type of rape seed oil make it unsuitable for human consumption, owing to the indigestibility of such large amounts of this acid. Erucic acid is also the major fatty acid to be found in nasturtium and crambe seeds (up to 75% and 56% respectively), and it is also found in the salad herb, rocket. 

Derivation Fats and oils from mustard seed, rape-seed, and crambe seed. 

The plant kingdom is estimated to offer >300,000 species available to man (1) of which only a few hundred are in organized agriculture. In 1957, the USDA initiated a program to collect >8000 different plant species, many of which were analyzed for potential sources of starch, protein, oil, fiber, medicinal components, as well as any other unusual materials. As a result of this effort, >100 new oils were discovered. Of these new oilseed plants, three have progressed to the point of commercial production, crambe, jojoba, and meadowfoam. In addition, lesquerella is almost sufficiently developed to begin production. The unique chemical structures of these four seed oils and how they affect the chemistry of the oil will be the basis of this chapter. 

Although erucic acid (22 1 13c) is present in seed oils of most Cruciferae, reaching a level of 80% in nasturtium seed oil, the most important erucic-con-taining oils are those from rape, mustard and Crambe abyssinica (Sections 3.3.27, 3.3.21 and 3.3.11). The... 

Over the past decade the nature of commercial rapeseed and rapeseed oil has changed dramatically (Andersson, 1981). Rape, mustard (B. alba, B. nigra) and crambe (Crambe abyssinica) seed oils all belong to the same family, the Cruciferae. In the past, they have been grouped together because they all contained significant quantities of erucic acid. Some commercial rapeseed oils are now very different because of their low erucic acid content. The classification of rapeseed is given in Table 3.92. 

Molecular Species of Triacylglycerols in the Mature Seed Oil of Crambe abyssinica ... 

Erucic acid is generally excluded from the sn-2 position of seed oil triglycerides (TAGs)of Brassicacea species. Stereospecific analyses ofBrassica juncea, B. napus, B. oleracea, B. rapa, Crambe abyssinica, Lunaria annua, Sinapis alba, and other wild Cruciferae (1-4) have not yet detected significant amounts of erucic acid in the sn-2 position. 

Fig. 3.17 (A) Changes in fatty acid composition of the triglycerides of soybeans during maturation. After Privett et al., 1973 [144]. (B) The influence of seed age on the incorporation of (2- C)-acetate into the seed-oil fatty acids of Crambe abyssinica. 16 0 palmitic, 16 1 palmitoleic, 18 1 oleic, 18 2 linoleic, 18 3 linolenic, 20 1 gadoleic, 22 1 erucic. After Appleby et al., 1974 [18]...

Gurr, M. I., Blades, J., Appleby, R. S.,Smith, C. G., Robinson, M. P., Nichols, B. W. (1974) Studies on seed oil triglycerides. Triglyceride biosynthesis and storage in whole seeds and oil bodies of Crambe abyssinica. 

Chinese tallow Crambe oil Crepsis foetida oil Croton oil Cuphea oil Jojoba oil Lesquerella seed oil Linseed oil Meadowfoam oil Neatsfoot oil Oitica oil Rapeseed ... 

Guan, R., U, X., Hofvander, R, Zhou, X.-R., Wang, D., Stymne, S., Zhu, L.-H., 2014. RNAi targeting putative genes in [hos[hatidylcholine turnover results in significant change in fatty add composition in Crambe abyssinica seed oil. Lipids 50, 407-416. 

Crambe Crambe abyssinica, C. hispanicd). Present interest in this oil, particularly in North Dakota and in Holland, depends on the fact that it is a potential source of erucic acid (50-55%) that finds several industrial uses. This was once the major acid in rapeseed oU, but modem varieties of this seed produce a low-emcic oil (such as canola) suitable for food use. High-emcic rapeseed oil is stUl grown for industrial purposes, and attempts are being made to increase the level of this C22 acid from around 50% to over 65% and even to 90% by genetic engineering (22-23, 44, 99-102). 

Crambe (Crambe abyssinica) and high-erucic acid rapeseed (Brassica napus) are oilseeds that contain large quantities of erucic acid 22 1 (A 13) as the main fatty acid component of the triglyceride. Crambe and high-erucic acid rapeseed (HEAR) contain 59.5 and 42% erucic acid, respectively (2). HEAR has more oil in the seed (42% compared with 35% for crambe). Both oilseeds are in commercial production with acreage in the tens of thousands and are grown mainly in the northern plains of the U.S. and Canada as well as eastern Europe (3). 

Elongation of fatty acids is important in two commercial oil seeds, rape and jojoba. Most varieties of rape accumulate large quantities of d5-13-docosenoic (erucic) acid in their seed triacylglycerols. This is formed by elongation of oleic acid and the reactions have been studied in rape and the closely related Crambe abyssinica (Appleby etaL, 1974). Elongation in jojoba (which accumulates lipid as wax esters) uses a system with oleoyl-CoA and malonyl-CoA as substrates. The enzymes involved have been studied in jojoba and other plants where very-long-chain fatty acids are synthesized (Pollard and Stumpf, 1980). 

For obvious reasons, studies on lipid content during seed or fruit development have concentrated on commercially important oil-rich seeds. Two excellent publications have reviewed much of the available data (Appelqvist, 1975 Hitchcock and Nichols, 1971). Plants which have been studied include the seeds of maize, Crambe abyssinica, rape, castor bean, soybean, flax, safflower, sunflower, white mustard, Crepis rubra, and Veronica anthelmin-tica and the fruits of the oil palm. Fat accumulation in oil-rich seeds generally occurs in three distinct stages. First, there is an interval of from 10 to 30 days after pollination when little fat accumulation takes place. This is followed by a stage of 2-5 weeks when a rapid increase in total lipid is observed. During the final stage, little change in lipid content occurs. 

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