The colour and appearance of a food greatly influences a consumer’s acceptability and the use of food colours in processed foods ensures just that.
Colour additives or food colour: Colour additives are non-nutritive substances that are used to enhance the appearance of a food product. Food in its raw state contains colour pigments that give it the characteristic colour, but exposure to light, air, temperature extremes, moisture and storage conditions change the natural colour of a food. Colour additives help correct natural variations in the colour of foods and provide colour to colourless items.
Colour additives used in food are of two types – natural and synthetic. Natural food colours are those that are extracted from seeds, flowers, insects and foods. These are usually less vibrant as compared to artificial colouring. One of the best known and widely used natural food colours is annatto – a yellow to red colouring material extracted from the pulp of the seeds of the lipstick pod plant. Annatto is used to add colour to butter, cheese, margarine and other foods. Cochineal – a red colour is another natural food colour that is extracted from the female insect coccus cacti. Other natural food colours include carotenes, saffron (kesar), turmeric, grape skin extract, beet root extract (betanin) and caramel.
Synthetic food colours or artificial food colours, as they are commonly known, are derived from coal tar or petroleum products or created by chemical synthesis. In recent years, a number of coal tar dyes have been found to be potent carcinogens and their use in foods has been restricted in many countries. In India the Prevention of Food Adulteration Act permits the use of the following synthetic colours in foods – Ponceau 4R,Carmoisine, Erythrosine, Tartrazine, Sunset Yellow FCF, Indigo Carmine, Brilliant Blue FCF and Fast Green FCF.
Artificial food colours have long been known to cause health problems. There is evidence that certain food colours – sunset yellow and tartrazine can trigger allergies in certain individuals, especially in those who suffer from asthma, sinusitis, rhinitis and skin allergies such as itchiness, urticaria or hives. Conditions such as hyperthyroidism can also be triggered by food colourings. Studies have also linked food colours to hyperactivity in children. Erythrosine and Fast Green FCF have been found to be potentially carcinogenic and tumorigenic.
Flavours and flavour enhancers: Flavouring additives are ingredients that add desired flavour to foods and are of three types – natural, nature-identical and artificial.
Natural flavouring substances include spices, herbs, roots, essences and essential oil.
Nature-identical flavouring substances are obtained by synthesis or are isolated through chemical processes in a laboratory but their chemical structures are identical to the substances present in natural products for example vanillin.
Artificial flavouring substances have no equivalent in nature and are typically produced by fractional distillation and additional chemical manipulation of naturally sourced chemicals or from crude oil or coal tar. Ethyl vanillin is a compound that smells and tastes like vanillin but is roughly three times more taste intensive as compared to natural vanillin when added to ice cream, confectionery and baked goods.
Flavour enhancers are compounds that are not flavours by themselves, but they enhance the flavour of other substances through a synergistic effect. One of the best known, widely used and somewhat controversial flavour enhancer is monosodium glutamate (MSG) or Ajinomoto or Chinese salt. Monosodium glutamate is the sodium salt of the amino acid glutamic acid.
MSG is Generally Recognized as Safe (GRAS); however some years ago a scare was created by results of a few research studies on MSG. A critical evaluation of these studies as well as subsequent studies have shown that only when very high doses of MSG were injected intravenously did it result in toxicity in selected animal species. Dietary MSG ingestion at any dose has not been shown to cause any adverse effects on health.
Some people are sensitive to large amounts of MSG particularly after eating Chinese food and develop symptoms of a condition known as Chinese Restaurant Syndrome. The symptoms includes numbness or a burning sensation at the back of the neck radiating to the arms, chest pain, general weakness, headache, nausea, palpitation and drowsiness. The exact cause of Chinese Restaurant Syndrome is not known, but it is thought to be caused by ingestion of large amounts of glutamate. The above symptoms can also occur after ingesting other foods that may trigger allergic reactions in sensitive individuals.
In India the Prevention of Food Adulteration Act (PFA), forbids using MSG in baby foods but permits its use in other foods provided that the total glutamate content of the ready to serve food does not exceed 1 per cent.
To be continued. . .
(Writer is a consultant nutritionist with 19 years of experience, practicing at Panaji and can be contacted on firstname.lastname@example.org)