What Chemicals are in Processed Foods?

Kate Onissiphorou

by Kate Onissiphorou

26th October 2022

Chemicals such as monosodium glutamate, sodium nitrite, and guar gum are commonly added to processed foods as a preservative or to enhance them in some way. While these types of chemicals are added intentionally, other dangerous chemicals can sometimes be induced during the manufacturing process.

From bacon and breakfast cereals to crisps, biscuits, and ice cream, our daily diet almost always includes processed food. These types of foods typically contain preservatives and other additives like artificial flavours and colours. Although many processed foods tend to be high in salt, sugar or fat, some processed products, like canned beans, are generally healthy.

Read on to find out more about the chemicals found in processed foods, why they’re used, and some common examples.

What are processed foods?

Technically speaking, processed foods are agricultural products that have been altered in one or more ways during preparation. Hence, they’re not limited to hotdogs and bacon. Foods can be altered in several ways, such as grinding, mixing, cooking, drying, freezing, canning, and baking. Food can also be altered by adding preservatives, artificial flavours, artificial colours, fortified nutrients, and any other chemicals.

Many processed foods are considered unhealthy because they often contain high levels of sugar, fat, and salt. However, some processed foods, such as yoghurt, are inherently healthy, while others may have fortified nutritional value because vitamins and minerals are added during production.

Cake, biscuits and crisps - unhealthy processed foods

Pastries, white bread and crisps are examples of unhealthy processed foods

Some examples of processed foods that form part of many people’s regular diets include:

  • Breakfast cereals
  • Instant coffee
  • Butter and margarine
  • Cheese
  • Cakes and biscuits
  • Bread
  • Doughnuts
  • Pizza
  • Ice cream
  • Crisps
  • Fizzy drinks

Why are chemicals used in processed foods?

Chemicals are used in processed foods for a variety of reasons, including to extend their shelf life, improve the taste or texture, enhance the colour, and increase the nutritional value.

  1. Food preservation – preservatives, such as saltpetre, are added to processed foods, especially meat products like bacon and hotdogs, to extend their shelf life. Food preservatives inhibit the growth of microorganisms, such as bacteria and fungi.
  2. Improve the taste – some foods have a naturally bland taste while others can become bland after undergoing various stages of processing. As a result, artificial flavourings are added to make them more palatable.
  3. Improve the texture – chemicals such as leavening agents can improve the texture of some processed food products like baked goods.
  4. Enhance the colour – artificial colours are added to enhance the aesthetic value of food that has an unattractive natural colour, or in cases where the natural colour has faded due to the manufacturing process.
  5. Increase the nutritional value – food products like fruits and vegetables can lose some of their nutrients during processing. To help rectify this, canned fruits and vegetables as well as other products, are fortified with vitamins and minerals to increase their nutritional value. An opened can of peaches with fruit spilling out

You can learn more about the chemistry of food additives and preservatives here.

Dangerous chemicals in processed foods

Although dangerous chemicals are not intentionally added to processed foods, some of these chemicals are induced by certain processing methods. For example, subjecting meat to high temperatures can induce the formation of carcinogenic chemicals known as heterocyclic amines.

Other examples of dangerous chemicals that are induced in food processing include:

  • Acrylamide – a product of sugars and amino acids, acrylamide is a carcinogenic chemical that’s formed when food is cooked at high temperatures 
  • Benzene – aside from processed meat products, benzene is produced from the reaction of benzoate salts and ascorbic acid (vitamin C) with light or heat. Sodium benzoate and ascorbic acid are commonly added to beverages as preservatives
  • Chloropropanols – these chemicals are formed from the chemical reaction of glycerol chlorine under acidic conditions
  • Ethanol – a type of alcohol that’s formed during the fermentation process
  • Ethyl carbamate – otherwise known as urethane, ethyl carbamate is not acutely toxic to humans but it may cause nausea and vomiting in high concentrations. The International Agency for Research on Cancer also found evidence that it has some carcinogenic properties
  • Furan – used in some manufacturing processes, furan is occasionally found in jarred and canned food products that have been subjected to heat. 

The hazards of food processing

Food processing is necessary for the mass production and mass distribution of food with a long shelf life. However, there are some hazards associated with processing food using high heat and chemicals. As we’ve already explained, certain processing methods can induce harmful chemicals that can contaminate food.

Chemicals found in processed foods

Aside from the chemicals listed above, here are some examples of chemicals that are intentionally added to processed foods. These additives are typically included in the ingredients, either as preservatives or flavourings.

  • Monosodium glutamate – although not a flavouring in itself, monosodium glutamate enhances the umami flavour of food and improves the taste
  • Artificial food colourings – these are water-soluble and edible dyes that can be added to foods such as pastries and sweets to enhance their aesthetic appeal
    Young girl eating a blue lollypop and sticking out her blue tongue

    Food colourings are intentionally added to processed foods

  • Sodium nitrite – commonly added to meat products, sodium nitrite is a preservative that inhibits the growth of bacteria and fungi
  • Guar gum – a long chain of carbohydrates, guar gum is used as a thickening and binding agent 
  • High-fructose corn syrup – a type of sweetener that’s commonly used in sweets and beverages
  • Carrageenan – derived from seaweed, carrageenan functions as an emulsifier, thickener, and preservative
  • Sodium benzoate – a chemical that’s used as a preservative for carbonated beverages and acidic food products like salad dressings
  • Trans fat – commonly added to improve the shelf life and consistency of food products.


Chemicals are added to processed foods for a variety of reasons, including to extend the shelf life, increase the nutritional value, and improve the flavour, colour, taste or texture. Some chemicals are added intentionally, while others may be induced during the manufacturing process.


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