Rapeseed glucosinolate content

The seeds contain 40-50% oil and 20-25% protein (dry matter basis [3]). Originally, the fatty acid with the highest share was erucic acid with 25-50% in the seed oil. Due to the negative nutritional effects attributed to eracic acid in Western countries, and because of glucosinolate contents, the composition of rapeseeds prevented the use of the oil for food and the use of the meal for fodder. 

After the oil has been extracted from rapeseed, the meal that remains contains 34-38% protein (at 8% moisture level). The amino acid balance of rapeseed protein is quite favorable however, the use of rapeseed meal in animal rations has been limited by its glucosinolate content (Bowland et ai, 1965). The antinutritional and goitrogenic cleavage products from these glucosinolates have a pungent taste that decreases the palatability of the feed. 

Czechoslovak zero -erucic rapeseed oils were examined for the levels of chlorophyll pigments in dependence to glucosinolate content of the rapeseed and its technological processing. Chlorophyll pigment interactions with some other components of the oil were also followed. 

Korolczuk and Rutkowski (78) examined the amino acid content of rapeseed isolates prepared by several methods. Glucosinolates were not present. They found that isolates are generally characterized by higher levels of essential amino... 

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. 

Mustard meal contains more glucosinolates than rapeseed, though of different kinds (Ravindran and Blair, 1992), the high content of glucosinolates... 

Canola Oil Canola oil is obtained from low erucic acid, low glucosinolate rapeseed. The unique polyunsaturated fatty acid and low saturated composition of canola oil differentiates it from other oils. It has a higher oleic acid (18 1) content (55%) and lower linoleic acid (18 2) content (26%) than most other vegetable oils, but it contains 8-12% of linolenic acid (18 3) (58). Canola oil is most widely used in Canada and is considered a nutritionally balanced oil because of its favorable ratio of near 2 1 for linoleic to linolenic acid content. Unlike most other edible oils, the major breakdown products of canola oil are the cis, trans- and tram, trans-2,4-heptadienals with an odor character generally described as oily, fatty, and putty. Stored canola oil shows a sharp increase in the content of its degradation products, which are well above their odor detection thresholds. The aroma is dominated by cis, tram-, tram, frani-2,4-heptadienals, hexanal, nonanal, and the cis, trans- and... 

Use as Human Food. Rapeseed, as a protein source for humans, has many obstacles to overcome. The glucosinolate and fiber contents require application of new processing technology (22, 30) to eliminate antinutritional qualities. Rapeseed flours, protein concentrates, and isolates are lower in protein but higher in crude fiber and ash contents than corresponding soybean products. Rapeseed flours are comparable to soybean flour in water adsorption and give much higher fat adsorption, oil... 

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. 

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. 

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