Chemistry Industry Serving the needs of Customers in Food Industry
Food additives are substances added to food to preserve flavor or enhance its taste and appearance. Some additives have been used for centuries; for example, preserving food by pickling (with vinegar), salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines. With the advent of processed foods in the second half of the 20th century, many more additives have been introduced, of both natural and artificial origin.
In the past century, new additives have been discovered and invented that can be used to improve food products at relatively low cost. The first of these included colours in cheese, emulsifiers in margarine, baking powder in cake mixes and gelling agents in jams. The past 40 or so years have seen dramatic developments in food science and technology, along with a substantial increase in the use of food additives. The food industry can now make a huge variety of products, with good and uniform quality, which are sold at reasonable prices.
Food additives and changing lifestyles
Our way of life has changed dramatically in the past few decades, with the busier lives we lead meaning we spend less time in the kitchen. New technology, combined with food additives, has made it possible for wholesome food to be prepared on a large scale at economical prices, allowing us to eat good food without spending hours cooking it.
Additives have also made convenience foods a possibility. From dry mixes for sauces, desserts and instant mashed potato to products like ready meals and snacks, none would be possible without additives.
Health and nutrition is another area where considerable progress has been made. Products such as margarines containing polyunsaturated fats or low-calorie products would be impossible without food additives. In fact, without additives, many of the food products we take for granted today simply would not exist.
Why are food additives used?
To maintain a food’s nutritional quality, for example by preventing vitamins, essential amino acids and unsaturated fats from degrading.
To improve a food’s keeping properties, for example by preventing mould from growing and slowing down the chemical reactions that make foods go off.
To provide products for consumers who have specific nutritional requirements, such as diabetics who need products containing sweeteners rather than sugar.
To maintain and improve a product’s sensory properties, such as texture, consistency, taste, aroma and colour.
To aid the manufacturing process of a food product, or its packaging, transport or storage.
To regulate these additives, and inform consumers, each additive is assigned a unique number, termed as "E numbers", which is used in Europe for all approved additives. This numbering scheme has now been adopted and extended by the Codex Alimentarius Commission to internationally identify all additives,regardless of whether they are approved for use.
E numbers are all prefixed by "E", but countries outside Europe use only the number, whether the additive is approved in Europe or not. For example, acetic acid is written as E260 on products sold in Europe, but is simply known as additive 260 in some countries. Additive 103, alkanet, is not approved for use in Europe so does not have an E number, although it is approved for use in Australia and New Zealand. Since 1987, Australia has had an approved system of labelling for additives in packaged foods. Each food additive has to be named or numbered. The numbers are the same as in Europe, but without the prefix 'E'.
The United States Food and Drug Administration lists these items as "Generally recognized as safe" or GRAS; they are listed under both their Chemical Abstract Services number and Fukda regulation under the US Code of Federal Regulations.
Where do food additives come from?
Plant sources: These include thickening agents extracted from fruit and seaweed; colours, isolated from seeds, fruit and vegetables; and ingredients that make a food more acidic, such as tartaric acid, which comes from fruit.
Nature-identical products: These ingredients are exactly the same as ingredients found in nature, but are made either chemically or by fermentation. Examples include antioxidants, such as ascorbic acid in fruit and tocopherols in vegetable oils; colours, such as the carotenoids that are commonly found in fruit and vegetables; and acidic ingredients such as the citric acid present in citrus fruit.
Modified natural substances: These include emulsifiers, which are derived from edible oils and organic acids; thickening agents like modified starches and modified cellulose; and bulk sweeteners, for example sorbitol and maltitol.
Man-made products: For some ingredients, there is no alternative but to use a completely synthetic product. Examples include antioxidants such as butylated hydroxyanisole; colours like indigotin and quinoline yellow
How is the safety of food additives evaluated in the European Union?
It is essential that before any additive is used in food, it must be rigorously tested to ensure that it is safe, and these results must be checked by independent experts. Only those additives that are shown to be safe at the levels of use that have been proposed are allowed to be used in food. It must also be proved that there is a need for the additive – if this need cannot be demonstrated, then the additive will not be allowed for use
The basic approach to evaluating the safety of food additives – or any substance, for that matter – involves toxicological testing. Various methods are used to assess the risks, primarily animal feeding studies, and these conclusions are used to predict what the effects will be in humans. This is used to establish an Acceptable Daily Intake, which is the level of an additive which it is safe to consume every day over an entire lifetime. This is used by regulatory agencies to set safe use levels for additives in food.
The extensive testing required, and their known purity, means that food additives are among the safest components of our diet.
The Acceptable Daily Intake, or ADI, is defined as an estimate of the amount of a food additive, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable health risk. It is measured in milligrams per kilogram of body weight.
The concept of the ADI was initially developed by the Joint FAO/WHO Expert Committee on Food Additives, or JEFCA. It was later endorsed by the Scientific Committee on Food, and its successor, the European Food Safety Authority (EFSA).
It is usually derived from long-term animal feeding studies. First, the No Adverse Effect Level is determined, which is the highest dose of an additive that can be fed to the most sensitive animal species on a daily basis with no toxic effects. A large safety factor is then added – usually by dividing the level in animals by 100 – to arrive at a safe level for humans. For example, if the no effect level in animals is found to be 100mg/kg, then the human ADI would be set at 1mg/kg.The safety factor is built in partly to account for the differences between animals and humans, and also to allow for the variability between different people, such as age, health and how well nourished they are.
The ADI is not a level of toxicity – it is a level that has been found to be safe. Consuming more than this on occasions is unlikely to cause health problems, as long as the average daily intake is below the ADI. It should always be compared with average consumption levels over long periods, not with intakes on a day-to-day basis.
ADI has been proved to be the best practical tool available for legislators. It has contributed to a uniform approach around the world to express the safety of a substance in relation to human consumption levels of additives.
Is there intolerance to food additives?
The term ‘food intolerance’ generally refers to any abnormal reactions some people may have to certain foods. These can include migraine headaches, diarrhoea, respiratory problems and skin rashes.
Intolerance to foods such as milk, eggs, fish, shellfish and wheat is surprisingly common, and may affect as many as one-in-30 of the adult population. In contrast, one of the most extensive and reliable investigations into food additive intolerance, carried out by a regional health authority in the UK,1 found that only three out of 18,000 subjects were found to have a food additive intolerance.
This finding confirms an earlier estimate by experts at the European Commission2 on sensitivity to food components and additives. In adults, food additive intolerance appears to affect only a very small proportion of the population.
It has been suggested that any intolerance to additives that does exist could be related not only to the sensitivity of the person but also to the level of consumption. If this is the case, then it might be expected that susceptible children with a low tolerance threshold might react adversely to the foods they enjoy, such as sweets, snacks or soft drinks.
Removing or substituting additives is likely to create more problems than it solves. For example, if preservatives and antioxidants are not used, health risks are likely to arise.
There is also a common misconception that just because an ingredient is ‘natural’ it is automatically safe. However, it has been known for many years that some natural substances can cause intolerance. Indeed, in the UK study two out of the three cases of intolerance were actually caused by a natural ingredient.
While intolerance to additives certainly exists, it is part of a much wider problem of intolerance to foods in general. The greatest safeguard that people with an intolerance of any kind can have is accurate information about precisely what affects them. Accurate information on the composition of food products is essential so that the problem ingredients can be avoided. Labelling plays an important role in this.
Food additives can be divided into several groups, although there is some overlap between them.
Food acids are added to make flavors "sharper", and also act as preservatives and antioxidants. Common food acids include vinegar, citric acid, tartaric acid, malic acid, fumaric acid, and lactic acid.
Acidity regulators are used to change or otherwise control the acidity and alkalinity of foods.
Anticaking agents keep powders such as milk powder from caking or sticking.
Antifoaming agents reduce or prevent foaming in foods.
Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food, and can be beneficial to health.
Bulking agents such as starch are additives that increase the bulk of a food without affecting its taste.
Colorings are added to food to replace colors lost during preparation, or to make food look more attractive.
Color retention agents
In contrast to colorings, color retention agents are used to preserve a food's existing color.
Emulsifiers allow water and oils to remain mixed together in an emulsion, as in mayonnaise, ice cream, and homogenized milk.
Flavors are additives that give food a particular taste or smell, and may be derived from natural ingredients or created artificially.
Flavor enhancers enhance a food's existing flavors. They may be extracted from natural sources (through distillation, solvent extraction, maceration, among other methods) or created artificially.
Flour treatment agents
Flour treatment agents are added to flour to improve its color or its use in baking.
Glazing agents provide a shiny appearance or protective coating to foods.
Humectants prevent foods from drying out.
Tracer gas allow for package integrity testing to prevent foods from being exposed to atmosphere, thus guaranteeing shelf life.
Preservatives prevent or inhibit spoilage of food due to fungi, bacteria and other microorganisms.
Stabilizers, thickeners and gelling agents, like agar or pectin (used in jam for example) give foods a firmer texture. While they are not true emulsifiers, they help to stabilize emulsions.
Sweeteners are added to foods for flavoring. Sweeteners other than sugar are added to keep the food energy (calories) low, or because they have beneficial effects for diabetes mellitus and tooth decay and diarrhea.
Thickeners are substances which, when added to the mixture, increase its viscosity without substantially modifying its other properties.
GLOBAL SALES of food additives were estimated at around USD 24.5bn in 2010 with a forecast future growth rate of 2.5%pa, according to new report The Global Food Additives Market