Lecithins
Manufacturing process
The process technologies involved in their production are as wide as the variety of different lecithin products available.
Concentrating only on lecithins of plant origin in this context, the common start for all of these is the isolation of the crude lecithin from vegetable oil.
The basic steps are shown below
CRUDE LECITHIN PRODUCTION
Plant lecithins are a by-product in the refining of vegetable oils. During the usual batch degumming process the crude oil is heated to about 70 °C, mixed with 2 % water and subjected to thorough stirring for about half an hour to an hour. This addition of water to the oil hydrates the polar lipids in the oil, making them insoluble. The resulting lecithin sludge is then separated by centrifuging.
This sludge is made up of water, phospholipids and glycolipids, some triglycerides, carbohydrates, traces of sterols, free fatty acids and carotenoids. The crude plant lecithin is obtained by careful drying.
The conditions during the de-gumming process, like the quality and origin of the oilseeds, have a considerable influence on the composition and quality of the crude lecithin.
In the further processing of lecithins, the following principal processes can be distinguished:
- Modification of lecithins
- Enzymatic modification
- Chemical modification (in most countries, limited to non-food applications)
- Solvent extraction
- De-oiling with acetone
- Fractionation with alcohol
- Chromatographic purification
It is also possible to combine individual processes and to combine the products with other functional constituents.
The aim of all the processes is to adapt the lecithin to suit specific application requirements by giving it technical or physiological properties that the natural substance does not possess.
Enzymatic Hydrolysis
The graphic below shows the basic effect of the enzymatic hydrolysis of phospholipids, resulting in a higher polarity of the phospholipid molecule, thereby generating superior emulsification properties (for example).
HYDROLYSIS
De-oiling with acetone
Plant lecithins contain about 30-40 % neutral lipids, mainly triglycerides. To improve the processing characteristics of high-viscosity crude lecithins and their dispersant properties, one can make use of the fact that while polar lipids (phospholipids and glycolipids) are almost insoluble in acetone, neutral lipids are readily dissolved.
Extraction with acetone yields deoiled lecithin qualities with a residual content of only 2-3 % neutral lipids.
These products will be in the form of powder or also can be granulated.
Fractionation with alcohol
Today the production of plant lecithin fractions largely makes use of ethanol or ethanol-water mixtures. The fractionation process takes advantage of the differences in solubility of the various phospholipids in ethanol.
Phosphatidylcholine in particular is readily soluble, whereas phosphatidylinositol and phosphatidic acid are virtually insoluble.
Phosphatidylethanolamine, like the neutral lipids, is found in both fractions, which are of growing economic interest because of their different technological properties, in particular: the alcohol-soluble fraction as an O/W emulsifier and the insoluble fraction as a W/O emulsifier.
For many years PC-enriched products have been of great importance for the dietetic sector.
The fractionation method with alcohol can be used on lecithins of natural composition, on modified lecithins and on de-oiled lecithins.
Certification system
As a customer solutions company, Cargill has established a product portfolio over the years that can supply, where required, lecithin originated from conventional (non-GM) sources using an Identity-Preservation supply chain program. With dedicated production lines, product segregation and documentation systems, Cargill’s externally audited processes can be considered an industry benchmark system for the production of conventional (non-GM) lecithin products. Lecithin produced through Cargill’s Identity-Preserved programs is in line with the EU regulatory requirements for exemption from mandatory labelling
Cargill lecithins produced in the US and Europe are Kosher and Halal certified. All regional, national and international certifications are issued by well-known official certification bodies and available upon request.
All Cargill lecithin production sites operate under Certified Quality Management Systems (ISO, AIB). Our European sites are also certified by GMP+.