High erucic acid rapeseed production

In China, canola-type rapeseed oil products still contribute a very small proportion of total rapeseed oil products. Oil from both high erucic acid rapeseed and canola rapeseed represent the largest use of edible oil at present. The oil from these two sources is almost entirely used as cooking oil. There are very little amounts of this oil used for margarine or shortening formulations at present. Efforts are being made to widen the spectrum of edible oil products and convert from HEAR cultivation to canola cultivation. 

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). 

In the Orient, both rapeseed and mustard oils are used extensively for food and large quantities of mustard are produced for oil in India, Pakistan and Bangladesh. In Canada and Europe there is no production of mustard oil for edible oil purposes. All edible Canadian rapeseed oil is now from canola varieties, i.e., derived from seed low in erucic acid and low in glucosino-lates. High erucic acid rapeseed oil is used exclusively for industrial purposes, such as lubricants, slip agents for molds, and polymers. In Canada these high erucic acid oils are produced and marketed separately from canola oil. Rapeseed oils in the Western World are either very low in erucic acid for edible use or very high (over 40%) in erucic acid for industrial use. 

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. 

Rapeseed oil constitutes a substantial proportion of the supply of edible oil to consumers in many parts of the world. It includes the original HEAR (high erucic acid rapeseed) oils, LEAR (low erucic acid rapeseed) oils and canola oils (canola is the name adopted by Canadians for the oil derived from the new rapeseed low in both erucic acid and glucosinolates). Since there are great differences in the kinds of edible oil products which these consumers prefer, the type and degree of processing that are applied to the oils vary markedly from country to country, and even within different regions of some countries. 

As has been stated in preceding sections many countries are following Canada s lead and are reducing, or eliminating, the production and use of high erucic acid rapeseed (HEAR) oil. The following are some examples of where HEAR oil continues to be used because of some desirable characteristic. 

Ackman, R.G. (1983) Chemical composition of rapeseed oil, in High and Low Erucic Acid Rapeseed Oils (eds. J.K.G. Kramer, F.D. Sauer and WJ. Pigden), Academic Press, Toronto, pp. 85—141. Ackman, R.G. (1990) Canola fatty acids — an ideal mixture for health, nutrition, and food use, in Canola and Rapeseed. Production, Chemistry, Nutrition and Processing Technology (ed F. Shahidi), Avi Book, Van Nostrand Reinhold, New York, pp. 81—98. 

Rapeseed meal is a by-product of the production of rapeseed oil. In the past, in the Orient the meal was used principally as a fertilizer with limited amounts fed to animals. In Canada and Europe, the meal was fed to livestock but with severe restrictions on its use because of its antinutritional (goitrogenic) effects in animals. Since 1974, however, with the availability of low glucosinolate low erucic acid rapeseed (double low) in Canada (i.e., canola), the production and use of the meal has increased substantially. The same trend is now occurring in Europe with the availability of double low rapeseed. The meal derived from these two types of rapeseed, i.e., high and low in glucosinolates, is handled separately in commerce. 

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 production of HEAR has been controlled by the Canadian Crushing Industry through contracts to meet expected demands for oil. Up to the present time only one company has been involved in this market and there has been no evidence of high erucic acid seed appearing in the edible oil export market. The Canadian Crushing Industry will continue to control this market as it is in their own best interests for the erucic acid content of Canadian rapeseed to remain low. 

The early high erucic acid containing rapeseed oils which have been used for cooking and in food products since ancient times do not appear to have had any nutritional or health problems associated with their use. At least no records have been found in early writings to suggest the occurrence of problems related to these oils. 

B. R. Stefansson, The development of improved rapeseed cultivcirs, m "High and low erucic acid rapeseed oils. Production, usage, chemistry, and toxicological evaluation," 3. K. G. Kramer, F. D. Sauer and W. 3. Pigden, eds.. Academic Press, Toronto (1983). 

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. 

Erucic acid is a fatty acid that has toxic properties and has been related to heart disease in humans. Glucosinolates give rise to breakdown products that are toxic to animals. These characteristics make rapeseed products unsuitable as animal feedstuffs but canola, like soybeans, contains both a high oil content and a high protein content and is an excellent feedstuff for poultry. 

Since the late 1960s to the present date, plant breeders have diligently selected rapeseed to minimize or eliminate the erucic acid from the oil and glucosinolates from the meal. Much of the recent expansion in the rapeseed industry in Canada and Europe is attributable to the dramatic improvements in the quality of oil and meal over the past 20 years. Another important factor is the wide adaptability of different types of rapeseed to different environments and their ability to thrive in harsh climates. In Canada and Europe most rapeseed is grown north of the 45° parallel. However, in China and India production is comparatively close to the equator, approximately 25°-40°N. This combination of improved quality and wide adaptability makes the crop very attractive to many developed and developing countries which are otherwise deficient in edible oil and in high protein meal. 

The changeover to rapeseed cultivars that produce seed oil low in erucic acid is essentially complete in most European countries. Cultivars low in both erucic acid and glucosinolates are being developed in several European countries. The development of canola cultivars has been somewhat slower in Europe than in Canada due to the necessity of transferring the canola characteristics to highly developed cultivars of winter forms of the crop. Some commercial production of winter canola is expected in Europe in... 

Rapeseed oil high in erucic acid should not be used as a source of fat in products intended for human or animal consumption. A similar recommendation is made with respect to marine oils rich in C20 (or greater) fatty acids. If such oils are to be used in human or animal nutrition, the long chain fatty acid content of the oil should be diluted down to acceptable levels. 

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