Colour of Food

Social evils flourish when people in general are not adequately conscious of the harmful potential of such practices. In our country, food adulteration has assumed such a menacing proportion that it is perhaps uppermost among the social evils of our time, which like other deep-rooted ones can hardly be eradicated or effectively checked by mere statutory measures without the awakening of mass awareness and continued vigilance. Around 30 per cent to 40 per cent of food articles sold in markets are adulterated. From perishable vegetables to foodgrains, edible oils/fats to milk and milk products, sugar and sugar based confectionery to fruit juices and soft drinks, baby food to spices - almost every item is adulterated before being sold in the market. Consumption of adulterated food is extremely harmful in terms of nutrition. It can cause permanent infirmities and sometimes even death. Indeed, the nation's health is in grave peril due to food adulteration.

Adulterants are foreign substances. In terms of the Food Safety and Standards Act, 2006 (FSSA, 2006) an 'adulterant' is any matter which is or could be used for making the food unsafe or substandard or mis-branded or containing extraneous matter. The consumers' acceptance of any food article is in general guided by its three essential attributes - wholesomeness (to ensure nutrition and pleasure of food), safety, and consumers' preference (to ensure money's worth). In terms of such attributes a food is called adulterated if its quality is diluted or adversely affected by the addition of even innocuous or health hazard substances, or by the abstraction of the nutritious portion. Or if the food in question is not natural in quality. Food adulteration takes into account not only the deliberate addition or subtraction or abstraction of substances but also their incidental contamination during the period of growth, harvesting, storage, processing, transport and distribution.

Adulteration of food occurs in different forms. 'Frank' adulteration, so-called, is intended to increase the bulk and weight by adding foreign materials such as stone chips, sand particles, dirt etc. Such types of adulteration are generally found in cereals like rice, wheat, pulses etc. In another type, adulterants are indistinguishable from food materials, specifically the addition of chalk or soapstone materials or of non-casein proteins in casein and milk products. The most common type is the addition of chemicals, synthetic or natural, to add to the colour, flavour, texture and general appearance so that it primarily satisfies the organoleptic (sensory) quality and secondarily the nutritive quality. Many of the chemicals added are prohibited by food laws and are potentially dangerous to the health of consumers. Markets are flooded with vegetables, fruit, fish, meat, poultry, and sweets, and processed food, indeed essential items to which colour has been added. Farmers and unscrupulous traders adulterate their produce or merchandise with harmful adherents to increase profits... regardless of the danger to human life.

Both nutrients and hazardous adulterants consumed with food articles enter and are transported to different parts of the anatomy. While some adulterants pass through the gastrointestinal tract unabsorbed, some are digested by enzymes or broken down by bacteria. However, the "transport", transformation, utilisation and accumulation processes that are involved while addressing a poison within a tissue or organ of the body are dependent on time. If small amounts are consumed regularly, the concentration will build up to a steady level in most tissues and organs over a certain period of time. So-called "fat soluble" compounds like DDT or PBB (Polybrominated biphenyls) are not only stored in the adipose tissues but also pass into the milk fat of lactating women. Lead is also an accumulative poison like mercury and cadmium. Once it is absorbed, it tends to accumulate in the body.

Mineral oil added to edible oils and fats cause cancer. Lead chromate added to turmeric powder and spices can cause lead poisoning - foot-drop, insomnia, constipation, anaemia and mental retardation. Mercury in mercury fungicides used to treat grains or mercury contaminated fish can cause brain damage, paralysis and death. Non-permitted coal-tar dyes like metanil yellow, sudan II and III, congo red etc. can cause allergies, liver damage, infertility, anaemia, cancer and birth defects. There are many other food adulterants with poisonous effects on health.

Consumers have the right to food safety. Mere awareness is not enough. Without consumers knowing what adulterants are, food safety will remain a half-baked idea. They can now detect adulteration on their own by using common chemicals at hand. Such tests can help them immensely to prevent consumption of adulterated foods. "An ounce of prevention is worth a pound of cure." - Benjamin Franklin.

Colour contributes substantially to the appeal of food. Consumers often judge the freshness and quality of foodstuff by their colour. The colour which has been found to be the most popular with the trade is non-permitted metanil yellow, a coal-tar dye. Almost all brightly coloured and highly polished pulses, sweets (laddoos, jalebis), sharbat, turmeric (whole and powdered), biryani, etc. have been found to be adulterated with this prohibited dye. If a magenta red colour develops on the addition of a few drops of hydrochloric acid (muriatic acid) to the sample of sweets, biriyani or sharbat, it can be deduced that the sample contains metanil yellow.

Checking for extraneous colouring agents in turmeric or chilli powder is far simpler: Sprinkle a small quantity of the spice sample into a glass of water. Artificial colorant imparts any colour to the water or descends as coloured streaks. Similarly chicory used to adulterate coffee powder can be detected by gently sprinkling coffee powder sample in a glass of water. The coffee floats over the water but chicory begins to sink down within a few seconds leaving behind them a trail of colour, due to a large amount of caramel. Water soluble artificial colour in chillies or turmeric powder can be detected by sprinkling a small quantity of sample on the surface of water contained in a glass tumbler. The water soluble colour will immediately start descending in colour streaks.

If effervescence is observed after adding a few drops of diluted hydrochloric acid on the sample of jaggery, it can be inferred that either washing soda or sodium bicarbonate or both have been mixed with jaggery.

It is common knowledge that Bengal gram, arhar and besan ( Bengal gram flour) are often adulterated by using khesari (lathyrus sativus), a kind of pulse that contains BOAA (Beta-N-Oxalyl Amino -L Alanine) that causes neuro lathyrism which can lead to paralysis of the limb. Its presence can be detected by a simple test. A small sample can be taken in a test tube and placed in simmering water. Appearance of pink coloration suggests that the sample contains khesari. Metanil yellow, a prohibited coal tar dye, if present will give a similar colour even without simmering.

Starch used to adulterate milk, curd, khoya, paneer, sweets can be easily detected by using tincture iodine - Boil the foodstuff, cool and add a few drops of tincture iodine. The blue colour indicates the presence of starch. Common salt is deceptively sold as iodised salt. This misbranding can be revealed by a simple test: Cut a piece of potato, add the sample of salt and wait a minute and add two drops of lemon juice. If iodised, it will have a blue colour. In case of common salt, there will be no blue colour. Sugar solution used to adulterate honey can easily be identified: A cotton wick dipped in pure honey, when lit, burns readily. If adulterated, the presence of water will not allow the honey to burn; if it does it will produce a cracking sound.

The problem of adulteration of oils and fats is rampant in the country. More than 60 per cent of unsealed edible oil sold in the market is adulterated. Petroleum oils are very much cheaper than any edible oil and petroleum fractions, especially the oil used in cars.