Science of Food Nutrition and Health

Vinod Puri

(Publishers: Austin Macauley Publishers, London, 2023)

Food Additives

The main objective of food preservation is to prevent food from spoiling, maintain its safety and quality, and ensure it is accessible for consumption throughout the year, especially during times of scarcity and famine.

Food additives have been utilized since ancient times to extend the shelf life of foods and can be dated back to Egyptian Papyri from approximately 1500 BC. Nonetheless, the comprehension of microbial decay and food spoilage only became apparent in the 19th century. 

Over time food scientists developed techniques such as heat sterilisation, canning, and sealing foods in airtight containers for food preservation and storage. With the advancement of technology, food processing techniques have become more advanced and sophisticated resulting in the application of techniques such as pasteurisation, vacuum sealing, freeze drying, irradiation, pulsed electric field electroporation (a combination of techniques involving the use of high-temperature during processing, low temperature during storage, increasing the acidity levels, lowering the redox potential, and application of chemical or bio preservatives), and natural and synthetic food additives.

Broadly a food additive is any substance added to the food.  FDA defines food additives as

‘any substance, the intended use of which results or may reasonably be expected to result, directly or indirectly, in its becoming a component or otherwise affecting the characteristics of any food.’

 

Further, the additives that are intentionally added to foods to impart certain functional characteristics are called direct additives. In contrast, the substances that may enter the foods during processing, packaging, and storing are called indirect additives.

Food additives are classified into various categories based on their functional characteristics. For example:

  • Acidity regulators, such as salts of acetic acid, benzoic acid, and sorbic acid, are used to maintain the desired pH, preserve taste, and inhibit the growth of microorganisms.
  • Anti-caking agents, such as sodium alumino-silicate in salts, sodium oxide in powdered eggs, and cellulose in parmesan cheese are used to prevent particle clumping.
  • Bulking agents are non-nutritive additives such as cellulose and its derivatives, sorbitol, and mannitol used to increase weight and volume.
  • Colours, such as natural extracts from plants, flowers, animals, minerals, or algae, or synthetic dyes or pigments capable of imparting colour to foods, enhance appearance and appeal to the consumer.
  • Emulsifiers, such as mono- or diglycerides of fatty acids, lecithin, and polysorbate are used to stabilise and increase the shelf life of food emulsions, particularly oil- and water-based emulsions.

 

  • Stabilisers, thickeners, and gelling agents, such as plant gums, alginates, pectin, starches, agar-agar, and gelatine are used to prevent the separation of food components in products like salad dressings, margarine, bread, ice cream, desserts, jellies, and jams.
  • Flavour enhancers, such as products derived from plants or animals, microbial fermentations, or synthesised artificially are used to enhance or supplement the taste and odour of the foods.
  • Glazing agents, such as beeswax, candela wax, carnauba wax, shellac, and microcrystalline wax are used to impart a shiny appearance to foods such as seafood, meats, candy, and snacks.
  • Humectants, such as sugar alcohols, glycerine, egg whites, and hydroxy acids are used to control microbial activity, retain moisture, and increase shelf life, particularly in fruit juices, confectionary and basked products.
  • Raising agents, such as baking powder and sodium bicarbonate are commonly used in bakery products to enhance their volume.
  • Foaming agents, such as proteins, alginic acid and its salts, poly glycol esters of fatty acids, and xanthan gums are used to facilitate the formation of air in liquid suspensions. They are widely used in carbonated soft drinks, beer, frozen carbonated beverages, juices, ice creams, sorbets, whipped cream, and cakes.
  • Sweeteners, such as sugar alcohols, saccharin, aspartame, and acesulfame potassium are used as low-calorie alternatives to imitate the sweetness of commonly used sugar
  • Antioxidants, such as ascorbic acids, gallates, tocopherols, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and t-butyl hydroquinone (TBHQ) are used to increase the shelf life of foods rich in oil and fats.
  • Preservatives, such as nitrites, sulphites, benzoates, BHA, and BHT are commonly used to prevent the growth of bacteria, and moulds to increase the safety and shelf life of processed foods.

Suffice it to say that food additives are now consumed worldwide and are a regular part of our daily food intake. The development of synthetic artificial thickeners, preservatives, emulsifiers, colours, and flavouring agents during the Industrial Revolution in the 20th century introduced new substances into the human diet. This led to the need for food regulatory agencies to monitor and regulate the addition of these substances to food products to prevent adulteration. Concerns about these additives' potential toxicity and carcinogenic properties prompted the establishment of international food regulation bodies to oversee the use of intentionally added chemicals in food.

The European Food Safety Authority was created to regulate and educate consumers. Each additive was given a unique number called an "E" number, which was used as the basis for the Codex Alimentarius, an international committee established by FAO/WHO in 1962 to introduce the International Numbering System (INS) for identifying additives in member countries. In the European Union (EU), the letter 'E' is added before the additive number, while other countries only use the number. Below is a list of EU and Codex Alimentarius codes for food additives:

Food Additive

EU Code Number

Codex Alimentarius INS

Colours

E 100-199

100 -199

Preservatives

E 200-299

200 - 299

Antioxidants and Acidity regulators

E 300-399

300 - 399

Thickeners, Stabilizers and Emulsifiers

E 400-499

40 -499

Acidity Regulators and Anticaking agents

E 500-599

500-599

Flavour Enhancers

E 600-699

600-699

Antibiotics

E700-799

700-799

Glazing agents, Gases and Sweeteners

E 800-899

800-899

Additional Chemicals

E 900-999

900-999

All food additives undergo thorough scientific assessment and evaluation to ensure safety and technological necessity, and they must be clearly labelled. The approval process for food additives is intricate and time-consuming, as their safety for consumption is rigorously evaluated. Currently, the EU has approved approximately 379 food additives for use. It is important to note that some additives approved in the EU may not be approved in the US or other countries, and vice versa.

Despite the stringent evaluation process, certain additives that were previously approved have been banned due to potential health concerns. In my upcoming blog post, I will delve into the use of additives and the health issues they may pose. For further information, please refer to Chapter 11 of my book, "The Science of Food Nutrition and Health."

 

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