The process technologies involved in the production of lecithin are as diverse as the variety of different lecithin products available.
For lecithins of plant origin, the common starting point 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 centrifugation.
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 composition and quality of the crude lecithin product are considerably influenced by the quality and origin of the oilseeds, as well as the conditions during the de-gumming process.
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)
- De-oiling with acetone
- Fractionation with alcohol
It is also possible to combine individual processes and to combine the products with other functional constituents.
The aim of these processes is to enhance the technical and functional properties of lecithin to meet specific application requirements.
The graphic below shows the basic effect of the enzymatic hydrolysis of phospholipids, resulting in a higher polarity of the phospholipid molecule, and enhancing lecithin’s emulsification properties (for example).
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 with a residual content of only 2-3% neutral lipids.
These products can occur in powder or granulated forms.
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 (PC) in particular is readily soluble, whereas phosphatidylinositol (PI) and phosphatidic acid are virtually insoluble.
Phosphatidylethanolamine (PE), 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.
As a customer solutions company, Cargill has established a product portfolio 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 labeling
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 under GMP.
Some Cargill products are only approved for use in certain geographies, end uses, and/or at certain usage levels. It is the customer's responsibility to determine, for a particular geography, that (i) the Cargill product, its use and usage levels, (ii) the customer's product and its use, and (iii) any claims made about the customer's product, all comply with applicable laws and regulations.