How and why Polysorbate 80 is used as a food additive

What is polysorbate 80?

Polysorbates are a group of molecules commonly added to foods, pharmaceuticals, and cosmetics to improve consistency. They are also commonly known under various brand names, such as Tween, Kolliphor, Scattics, Alkest, Canarcel, and Kotilen.

Overall, these molecules share the same basic structure of a hydrophilic group and a long hydrophobic tail (a fatty acid chain), making them amphiphilic. Because of this, polysorbates are able to function as emulsifiers and surfactants in a variety of applications.

Polysorbate 80 exists as a viscous yellow liquid.

How is polysorbate 80 different from the other polysorbates?

There are other forms of polysorbate, besides polysorbate 80. For example, you might also see polysorbate 20, polysorbate 40, and polysorbate 60. So, what’s the difference?

The number following the name “polysorbate” is used to indicate the fatty acid chain on the molecule. In the case of polysorbate 80, the fatty acid is oleic acid.

Because of this, another name for polysorbate 80 is polyoxyethylene (20) sorbitan monooleate.

The number 20 (following polyoxyethylene) refers to the number of oxyethylene groups on the molecule, separate from the fatty acid chain.

The length of the fatty acid chain changes the chemistry, which means that the different polysorbate molecules may be more or less suited for certain applications.

What is an emulsifier?

Think about what happens when you make a salad dressing of oil and vinegar in a jar. If you shake the jar, they briefly mix, but then they immediately separate into two layers. That’s because the oil is composed of lipids, and the vinegar is water-based. The hydrophobic oily parts prefer to mix only with their own kind, because it is not energetically favorable to break up the intermolecular forces and form new ones with the vinegar.

If we add an emulsifier, like polysorbate 80, then we can bridge the gap between the hydrophobic and hydrophilic components of the dressing. Polysorbate 80 is perfect for this because it has both a hydrophilic head and a hydrophobic tail. Polysorbates are an example of low molecular weight amphiphilic emulsifiers. They are classified as non-ionic because they do not have a charge.

Emulsifiers can also be natural components of food. For example, lecithin is a phospholipid and surfactant that is present in plants and egg yolks.

What is food grade polysorbate 80?

Polysorbates are sold in different chemical grades depending on the intended use. For example, food grade polysorbate is suitable for use as a food additive, provided the added amount is kept within the regulatory limits. Food grade polysorbate has a higher quality standard compared to cosmetic grade polysorbate.

Why is polysorbate 80 added to foods?

Because of its amphiphilic structure, polysorbate 80 makes an excellent low molecular weight emulsifier. They are added to improve the texture, consistency, or smoothness of foods, and may also function as a preservative.

Let’s look at cocoa powder as an example. Cocoa butter is extracted from the beans, and the beans are roasted to make cocoa powder. Cocoa butter is not completely removed from the beans during the initial extraction. In fact, the remaining cocoa butter improves the mouthfeel and flavor of the chocolate product (for example, a chocolate drink mix). The problem is that, unless an emulsifier is added, the cocoa butter will separate out and compromise the organoleptic acceptability of the product.

Here are several additional examples of how polysorbate might be added to food products.

• Improve firmness and volume of breads and bakery products
• Solubilize oils into water-based products
• Stabilize oil-in-water emulsions (like in dressings)
• Prevent the separation of cocoa butter in chocolate products
• Improve texture and consistency of nonfat ice creams

Is polysorbate 80 a safe food additive?

Polysorbate 80 is an approved food additive emulsifier, also known by the code E433. The acceptable daily intake is set at 25mg/kg of body weight.

There is some preliminary research suggesting that high doses of polysorbate 80 and related compounds could negatively impact the intestinal environment, leading to complications like intestinal inflammation, intestinal permeability, and colitis. However, these studies were conducted in animal models and at much higher doses than would likely be consumed by humans. More human studies are needed to conclusively assess the safety of these food additives.

Conclusion

Polysorbate 80 is a low molecular weight, nonionic, amphiphilic compound. It is commonly used as an emulsifier in foods to improve texture, consistency, and mouthfeel of food products. Food grade polysorbate 80 may be used in bakery products to improve density, as a solubilizer in water-oil mixtures, and as a texture-enhancer in chocolate and ice cream.

References

Cox, S., Sandall, A., Smith, L., Rossi, M., & Whelan, K. (2021). Food additive emulsifiers: a review of their role in foods, legislation and classifications, presence in food supply, dietary exposure, and safety assessment. Nutrition reviews, 79(6), 726-741.

Thuy, N. M., Ha, H. T. N., & Tai, N. V. (2020). Effect of emulsifiers on viscosity and emulsion stability of the cocoa powder mixture. Food Res, 4, 2306-12.