Add oil to water, and they stubbornly refuse to mix. That is, until you introduce an emulsifier. Emulsifiers are essential ingredients that explain why mayonnaise doesn’t separate, how chocolate gets its shape, and why bread stays fresh longer. This article dives deep into the world of emulsifiers, exploring what they are, how they work, and their crucial role in the foods we consume.
What Are Emulsifiers and How Do They Work in Food?
Emulsifiers are food additives that facilitate the mixing of two or more liquids that would otherwise separate, such as oil and water. These additives are molecules possessing a unique structure: one end is hydrophilic (water-loving), while the other is hydrophobic (oil-loving).
When an emulsifier is added to a mixture of oil and water, the emulsifier molecules position themselves at the interface where the oil and water meet. The hydrophilic end of the emulsifier molecule orients itself towards the water phase, while the hydrophobic end faces the oil phase. This arrangement allows the oil and water to become finely dispersed within each other, creating a stable, homogenous, and smooth emulsion.
Fig. 1 – Emulsifiers work by positioning themselves at the interface of oil and water, stabilizing the mixture.
Emulsifiers significantly improve the appearance, taste, texture, and shelf life of food products. Many foods we enjoy daily, including margarine, mayonnaise, creamy sauces, candies, packaged processed foods, confections, and baked goods, wouldn’t possess the same desirable qualities without emulsifiers.
Different Types of Emulsifiers Used in Food
Emulsifiers used in food production are typically derived from purified natural sources (either plant or animal) or are synthetic chemicals closely resembling natural compounds.
For instance, lecithin (E322), a common emulsifier in chocolate, can be extracted from soybeans, eggs, liver, peanuts, and wheat germ. Pectin (E440), another widely used emulsifier, is naturally present in fruits like apples and pears.
The European Union (EU) currently permits the use of approximately 60 additives categorized as ’emulsifiers, stabilizers, gelling agents, and thickeners’. Here’s a table outlining some common emulsifiers, their E-numbers, and typical food applications:
| E-numbers | Substance/class | Some foodstuff in which they are commonly used |
|---|---|---|
| E322 | Lecithin | Chocolate products |
| E407 | Carrageenan | Flavored milk, iced coffee, dairy-based ice cream, chilled desserts, cream |
| E412 | Guar gum | Dairy-based products, soy-based products, frozen desserts, sandwich fillers, salad products |
| E415 | Xanthan gum | Mayonnaise, sandwich fillers, salad products, dressing, table sauces |
| E432-436 | Polysorbates | Fine bakery wares, milk and cream analogues, ice cream, desserts, sugar confectionery |
| E460-469 | Celluloses | Vitamin supplements, artificial sweeteners, meal replacements, ice lollies, meat substitutes |
| E471 | Mono- and diglycerides of fatty acids | Dairy-based ice cream, margarine, cakes, pastries, frozen desserts, sandwiches and wraps |
| E473-474 | Sucrose esters and sucroglycerides | Gum, plant-based ice cream, pastilles, plant-based drinks, snack/cereal/energy bars |
| E475 | Polyglycerol esters of fatty acids | Cakes, pastries, sweet biscuits/cookies, baking ingredients, frozen desserts |
| E476 | Polyglycerol polyricinoleate | Chocolate products, dairy-based frozen products, margarine |
| E481-482 | Stearoyl lactylates | Fine bakery wares, breakfast cereals, desserts, bread |
| E491-495 | Sorbitan esters | Cakes, pastries, baking ingredients, chocolate products |
Common Applications of Emulsifiers in Food Production
Emulsifiers are indispensable in a wide array of food products. Here are some common examples:
Bread
While bread can be made without emulsifiers, the resulting product is often dry, has low volume, and stales quickly. Adding as little as 0.5% emulsifier to the dough can significantly improve volume, create a softer crumb structure, and extend shelf life. Dough strengtheners (e.g., diacetyl tartaric acid esters (E472e) and sodium or calcium stearoyl-2-lactylate (E481, E482)) enhance dough strength, leading to improved texture and volume in the bread. Dough softeners (e.g., mono- and di-glycerides of fatty acids (E471)) create a softer crumb and increase shelf life.
Chocolate
Lecithin (E322) or ammonium phosphatide (E442) are added to all chocolate products (typically around 0.5%) to achieve the desired consistency. These emulsifiers enable chocolate to be molded into bars and other shapes. If chocolate is stored at high temperatures, “bloom” (a dull or white surface) can occur, making the product less appealing. Sorbitan tristearate (E492) can help delay the development of bloom.
Ice Cream
Ice cream is a complex food containing ice crystals, air, fat particles, and an unfrozen aqueous mix. Emulsifiers added during the freezing process promote a smoother texture, prevent rapid melting, and improve freeze-thaw stability. Mono and diglycerides of fatty acids (E471), lecithin (E322), and polysorbates (E432, E436) are commonly used in ice cream production. These principles apply to other frozen desserts like sorbet, milkshakes, frozen mousse, and frozen yogurt.
Margarine
Emulsifiers provide margarine with the required stability, texture, and taste. Mono and diglycerides of fatty acids (E471) and lecithin (E322) are widely used to ensure that water droplets are finely dispersed in the oil phase. Citric acid esters of mono and diglycerides (E472c) prevent splattering during cooking, while polyglycerol esters (E477) and lactic acid esters contribute to the quality of margarine used in baking.
Processed Meat
Sausages, a staple in Europe’s processed meat industry, rely on emulsifiers to bind meat proteins, fat, and water into a stable emulsion. Emulsifiers stabilize this emulsion and evenly distribute fat throughout the product. In low-fat meat products, emulsifiers help replicate the pleasant taste and texture of their full-fat counterparts. The food industry utilizes mono and diglycerides of fatty acids (E471) and citric acid esters (E472c) in manufacturing processed meat.
Food Safety and Legislation
Like all food additives, emulsifiers are subject to rigorous EU legislation governing their safety assessment, authorization, use, and labeling. All added emulsifiers must be specified on product labels, either by name or E-number, preceded by their technological function (e.g., emulsifier: E466 or emulsifier: carboxymethylcellulose).
In Conclusion
Emulsifiers are vital food additives that act as stabilizers in emulsions, preventing liquids that normally separate from doing so. They are prevalent in the food supply and play a key role in enhancing the appearance, texture, and shelf life of many commonly consumed foods.
This article was produced in collaboration with FoodSafety4EU as part of a joint food additive campaign. FoodSafety4EU has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No. 101000613.
References
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