Rapeseed lecithin production

From a commercial point of view, soybean is the most important source for lecithin however, lecithin production from sunflower (180) and rapeseed (181-183) wet gum has also been successful. Wet gum is removed during the first refining step of crude oil that is the degumming process. Traditionally, crude oil obtained from solvent-extraction process is agitated with 1-3% water at elevated temperatures (70-80°C). Under these conditions, phosphohpids and glycohpids start to swell and become insoluble in the oil. The hydrated mass is removed via centrifugation, and the dehydration is carried out under vacuum until the residual moisture is below 1%. 

Another way to increase the phosphatidylcholine content in lecithin is enzymatic transesterification after the addition of choline. Alternatively, modification can be achieved by the addition of free fatty acids, which make the product more fluid. Chemical modification of lecithin (hydrogenation and hydroxylation of the double bonds of fatty acids) is used to increase its stabihty against oxidation. For specific purposes, a phosphohpid concentrate (>90% ofphospho-hpids) is produced by a selective extraction that separates neutral hpids, especially triacylglycerols and free fatty acids. The most important product for industrial purposes is soy lecithin. Its composition is shown in Table 3.33. Rapeseed lecithin and sunflower lecithin have quite a different phosphohpid fraction composition. 

Some European countries, such as Hungary, Ukraine and France, and Argentina grow and process sunflower seeds for oil production. Rapeseed lecithin is produced in some Canadian and European crushing plants. In principle it is possible to process lecithin with good phospholipid composition from expelled seed oils only, but the availability is small. 

Cmde oils generally contain phospholipids that are removed during the degum-ming stage of refining as a crude mixture (lecithin). This valuable product is the basis of the phospholipid industry, and phospholipids are used extensively in food products, in animal feeds, and in industrial processes. The major members are phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinositols and are accompanied by smaller proportions of other phospholipids. Soybean oil (3.2%), rapeseed oil (2.5%), and sunflower seed oil (1.5%) contain the proportions of total phospholipids indicated in parentheses and are the main sources of commercial lecithins, especially soya lecithin. Palm oil contains little or no phospholipids (7-9). 

The European reaction to traces of GMO DNA in foods has markedly affected the uses of phospholipids in food and health applications. The consumers right to know, and ingredient users avoidance of GM products, has led to a decrease in soybean and corn lecithin usage, with a shift to the usage of soft-seed lecithins (rapeseed and sunflower) that are non-GMO. 

Lecithins are essential components of cell membranes and, in principle, may be obtained from a wide variety of living matter. In practice, however, lecithins are usually obtained from vegetable products such as soybean, peanut, cottonseed, sunflower, rapeseed, corn, or groundnut oils. Soybean lecithin is the most commercially important vegetable lecithin. Lecithin... 

Other somewhat less-rich sources of lecithin are cottonseed, rapeseed and sunflower oils, but palm oil contains very little (Figure 12.31). Soya beans account for over half the world production of all oilseeds and vegetable oils. The United States is the largest soya producer ( 60%) and Brazil the second ( 20%) (Tables 12.44 and 12.45). 

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