Discovering Lecithin: A Versatile Natural Ingredient

Emulsions are classified by HLB (Hydrophilic Lipophilic Balance, a scale from 1 to 20), which gives a value for the degree of presence of oil or water in the emulsion, with low values being very lipophilic and greater than 10 being very hydrophilic.

The structure of lecithin

Physically, lecithin is a phospholipid consisting of:

• Hydrophobic part formed by fatty acid chains.
• Hydrophilic part formed by the choline and the phosphate group.

Lecithin’s are commercially available in 3 different formats:

1.    Fluid lecithin:

Liquid or fluid lecithin (60% phospholipids):

This is a product with high viscosity, emulsifying and fluidizing properties, essential in the manufacture of chocolate (HLB between 3-4).

Liquid lecithin variant, partially hydrolysed:

In this case, and only as an exception, the legislation allows a minimum phospholipid content of 56% instead of 60%. Its use is more hydrophilic and one of the applications is to avoid splattering when using margarine for frying. (HLB 9)

2.    Powder or deoiled lecithin:

It is so called because it is obtained by increasing the purity of IA up to 97% by eliminating the fat. It is a product used in different applications due to its easy handling (HLB 4-5).

3.    Lecithin specialties:

Powder variant:

Application of liquid lecithin on a powder carrier (wheat flour, soya flour). IA content between 12-15 %.

Liquid variant:

Mix of two liquid products and in the conversion to powder form by drying (mainly spray drying).An Example would be a combination of whey and lecithin. IA content between 25-30%.

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Lecithin in Instantizing technology

Lecithin has the ability to improve the dispersion of powdered products. It has this function because it possesses two essential factors:

• It shortens the sinking time of the powder in the liquid.
• It stabilizes the emulsion, through a fine and stable dispersion.

The following product types profit from the addition of Lecithin:

• Hydrophobic powders such as whole milk, cocoa powder or some milk formulas for infants.
• Hydrophilic powders such as caseinates, protein drinks, some lacto-serum, which are difficult to disperse due to their particle size.

The two essential factors of lecithin in this application play a key role in improving its ability to disperse in the liquid but also once dispersed, to stabilize it. Factors such as temperature can help in dispersing but not in keeping it stable.

Technologically, there are different Lecithination methods depending on the product to be solubilized, but basically it is a matter of incorporating the lecithin in small microparticles on the powdered product (ideally in the form of a spray) and mixing it correctly to achieve a good homogenization and avoid the formation of lumps. 

In the industry there are processes adapted to this application, the Lödige technology being one of the most advanced. However, this method can have difficulties due to the high viscosity of lecithin, so it is necessary to heat it to temperatures close to 60-70 ºC or to use lecithin "diluted" in oils. Other systems use lecithin in powder form actively mixed with the product to be instantized. The latter method is easier but the results are less reliable.