The substances that are not normally consumed as food itself but are added to food for one or more technological purposes are food additives.
As per Codex, food additive means any substance not normally consumed as a food itself and not normally used as a typical ingredient of food, whether or not it has nutritive value, the intentional addition of which to food for a technological purpose in the manufacture, processing, preparation, treatment, packaging, transport or holding of such food results or may be reasonably expected to result (directly or indirectly) in it or its by-products becoming a component or otherwise affecting the characteristics of such foods. They maintain or improve the safety, freshness, taste, texture or appearance of the food.
The international body which evaluates the safety of food additives is the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Only food additives that have been evaluated and deemed safe by JECFA, on the basis of which maximum use levels have been established by the Codex Alimentarius Commission can be used in foods that are traded internationally.
Codex standards are the reference for national standards for consumer protection, and for the international trade in food, so that consumers everywhere can be confident that the food they eat meets the agreed standards for safety and quality, no matter where it was produced. The use of food additives is subject to strict regulations and controls, which are backed by scientific studies to demonstrate their safety to human health.
Food additives are classified as direct (intentional) or indirect (incidental) food additives. The additives that are added to a food for a specific purpose in that food are known as direct food additives. For example, xanthan gum, which is used in salad dressings, chocolate milk, bakery fillings, puddings and other foods to add texture, is a direct additive.
Mostly such type of additives can be easily identified on the ingredient label of foods, either by a specific number or directly by the name of the additive. Whereas, indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or other handling. For instance, minute amounts of packaging substances may diffuse from the package into foods during storage. As a result, food packaging manufacturers must prove to the US Food and Drug Administration (FDA)/Food Safety and Standards Authority of India (FSSAI) that all materials coming in contact with food are safe before they are permitted for use in such a manner.
The levels of both direct and indirect food additives are controlled by national regulatory authorities, like FSSAI in India. A same additive may have different permissible levels depending on the type of food. For instance, Sucralose in dried fruit may be used up to 1,500 mg/kg whereas in frozen fruit its maximum level is only 400 mg/kg. This shows that the different type of foods may induce certain effects, which change the permissible amount of additive in that particular food. Hence, the regulatory studies are very important.
Classification of direct food additives
1. Colouring Agents: These are the substances which are used to impart, preserve, or enhance the colour of a product. They are added to increase the visual attractiveness or to compensate for natural colour variations in food. E.g. tartrazine (yellow), ß-carotene (red-orange) and turmeric (yellow).
2. Preservatives: As the name suggests, these substances are used to preserve food by preventing growth of microorganisms and subsequent spoilage, including fungistats, mould and rope inhibitors. E.g. nisin (processed cheese, meats), sodium benzoate (salad dressings, jams) and nitrates (cured meat).
3. Flavouring Agents: These are added to impart or help impart a taste or aroma in food. They may be natural or synthetic. They are normally classified into three categories natural flavouring and artificial flavourings and nature-identical flavourings. Natural flavouring substances are extracted from plants, herbs and spices, animals, or microbial fermentations. Artificial flavouring agents are chemically similar to natural flavourings but are more easily available and less expensive. Whereas nature-identical flavouring agents are the flavouring substances that are obtained by synthesis or are isolated through chemical processes. E.g., cinnamon, zingerone and ethyl maltol.
4. Antioxidants: Substances used to preserve food by retarding deterioration, rancidity or discolouration due to oxidation. E.g., Butylatedhydroxianisole (BHA) and Butylatedhydroxytoluene (BHT).
5. Emulsifiers: These modify the surface tension in the component phase of an emulsion to establish a uniform dispersion or emulsion. E.g., Phosphate esters of mono- and diglycerides, calcium stearate.
6. Stabilisers and Thickeners: Substances which are used to produce viscous solutions or dispersions, to impart body, improve consistency, or stabilise emulsions, including suspending and bodying agents, setting agents, jellying agents and bulking agents. E.g., calcium acetate, pectin, xanthan gum.
7. Acids and Bases: These are added to change or maintain the acidity or basicity, including buffers, acids, alkalis and neutralising agents such as acetic acid and propionic acid.
8. Sweeteners: Sweeteners are carbohydrates characterised by their sweet taste. Besides providing a sweet taste, they also affect fermentability, appearance, flavour, dimensions, colour and texture of the finished products. Majorly they are of two types, i.e. Nutritive and Non-Nutritive. E.g., sucrose, glucose, sorbitol and neotame.
Substances used in food-contact articles (e.g., food packaging or food processing equipment) that migrate, or that may be expected to migrate; into food at negligible levels are the indirect food additives. These include adhesives and components of coatings (Acrylate ester copolymer coating, Resinous and polymeric coatings), paper and paperboard components (Acrylamide-acrylic acid resins, Alkyl ketene dimers), polymers (Cellophane, Acrylonitrile/styrene copolymer, Polycarbonate resins) and adjuvants and production aids (Emulsifiers, Reinforced wax, Synthetic Fatty alcohols).
General principles for using food additives
1. The food additive must be safe, i.e., it should not present any health risk to consumers.
2. Quantity of the additive added is below the maximum use level and is the lowest to provide the intended effect.
3. It should not mislead or deceive consumers.
So it can be concluded that food additives when added intentionally improve the quality of the food product provided they are added within the permissible limit. Precaution should be taken while selecting the packaging material and processing equipments so that the chances of unintentional addition of food additives may be avoided.
(Dr Singh is Assistant Professor and Thakur is M Tech student at Department of Food Science and Technology, National Institute of Food Technology Entrepreneurship & Management (NIFTEM), Haryana. They can be contacted at anurag.niftem@gmail.com)