World

Food Safety

Day: ​How To Check For Adulteration In Household Food Products

Quick Summary

World Food Safety Day is observed every June 7, established by the United Nations in 2018 to raise awareness about the risks of unsafe food around the world. Data from the World Health Organisation (WHO) reveals that contaminated food causes 600 million illnesses and 420,000 preventable deaths each year, globally. Grains, dairy, spices and even vegetables and fruits can be adulterated, and remain undetected quite easily. There are ways to catch that with Indian bodies like the FSSAI’s handbook.

Deep Dive

The Food Safety and Standards Authority of India (FSSAI) has published a publicly accessible manual called DART (Detect Adulteration with Rapid Test), which provides over 50 quick household tests to detect adulterants in common food products, from milk and ghee to spices, grains, and fresh produce sold by your local green grocer. This article will help you navigate food adulteration, using FSSAI's DART framework, and what distinguishes adulteration from contamination, and what to look for while buying each category at the market. 

Adulterated vs Contaminated Food

As per the FSSAI's definition under the Food Safety and Standards Act, 2006, food adulteration refers to the deliberate addition of poor-quality or harmful substances, the substitution of one ingredient for another, or the removal of a valuable component. All of these lower the quality, nutritional value, or safety of the product.

Contamination can be either accidental or incidental and occurs when harmful substances enter food during cultivation, harvesting, storage, processing, transportation, or distribution. It can happen through negligence or environmental exposure rather than deliberate intent. 

Contamination is often invisible without laboratory testing and is addressed through sourcing, hygienic storage, and regulatory enforcement. Adulteration, particularly of the kinds widespread in India's informal food market, is frequently detectable using simple household methods, where FSSAI’s DART framework will come in handy. It’s worth a look this World Food Safety Day.

What to understand before using any home test:

• Home tests are screening tools, not laboratory-grade confirmations

• If there is a positive result, stop consumption, report to the FSSAI via helpline 1800-11-4000 or the Food Safety Connect app

• Boiling food does not remove chemical adulterants.

• Packaged food from FSSAI-licensed brands is more rigorously tested than market produce, but is not immune to adulteration.

Checking for Adulteration at the Time of Purchase

Across all categories, there are some basic checks you need to do to make sure you have a product that is certified safe:

At the market or store:

• Check for a valid FSSAI licence or registration number on all packaged products. It is mandatory for every food business under the FSS Act, 2006

• Be sceptical of products priced significantly below market rate. If the price seems too good to be true for the claimed quality, adulteration is a likely possibility.

• Buy from FSSAI-certified vendors and outlets with a Food Safety Display Board (FSDB), which is mandated for fresh produce retailers.

• For loose, unpackaged products (spices, grains, dairy), buy from known, traceable suppliers.

• For packaged spices, look for the ISI mark, FSSAI licence number, and clear batch or expiry information on the label.

Category 1: Dairy Products

The most common food category that faces adulteration is dairy products. A 2011 FSSAI national survey across 33 states found that 68.4% of milk samples tested did not conform to FSSAI standards. Here’s how to check for the purity of milk, this World Food Safety Day.

Milk

Milk is the most widely consumed product across Indian households for its wholesome properties, and the most commonly adulterated food item as well. The most common adulterants tend to be water, detergent, starch, urea, and formalin.

• Water: Do the slope test by placing a drop of milk on a clean, polished, slightly tilted surface. Unadulterated milk will barely flow down and leave a trail.

• Detergent: Do the shake test by taking equal parts milk and water in a small transparent container. Shake well for half a minute. Unadulterated milk will froth up and also go back to its original froth-free appearance quickly.

• Starch: Do the iodine test by boiling some milk with slightly more water than milk. Cool the water-milk liquid and once at room temperature, add 2-3 drops of tincture of iodine. Unadulterated milk produces no colour change, while starchy milk will turn blue.

Ghee

Pure ghee’s marker is its rich smell; adulterated ones tend to be mixed with vanaspati, animal fat, starch, mashed potato or sweet potato. A recent example of such a case was the Tirupati Laddu controversy in 2024, where synthetic vegetable oils and chemicals were used to masquerade as pure ghee. To spot:

• Vanaspati: Add an equal part of concentrated hydrochloric acid and a pinch of sugar into a stoppered test tube. Shake for about a minute, and let it rest for 5 minutes. If the acid layer turns red, vanaspati is present. Pure ghee does not show any colour change.

• Starch of potato: Do the iodine test by taking some ghee in a transparent bowl and adding 2-3 drops of tincture of iodine. Pure ghee shows no colour change. If the iodine turns blue, there is starch present.

Paneer

One of the more common dairy products susceptible to adulteration is paneer. There is analogue paneer, which is made with vegetable fats after synthesis, starches and other additives to mimic paneer. It lacks the softness and milky smell of actual paneer. You can spot the difference in a homemade paneer butter masala versus an adulterated version at some restaurants. Luckily, the FSSAI has issued a rule for the two different products to be labelled separately.

To test for starch, boil a small quantity of paneer in water and let it cool. Add a few drops of iodine solution, and if it turns blue, starch is present. If it remains unaffected, the paneer is unadulterated.

Note: While purchasing, press a piece of fresh paneer. It should feel soft, not rubbery or crumbly. A rubbery feel or extra whiteness could be an indicator of adulteration.

Category 2: Spices

A spice controversy had erupted in 2024, all of which were exported, with around 12% of the powdered spice samples tested that failed to meet FSSAI safety standards, with pesticide residues and added colourants among the most common violations.

Turmeric Powder

Pure turmeric powder has an earthy smell. Two yellow shade-producing chemicals are added to turmeric powder: lead chromate (for a brighter yellow colour) and metanil yellow (an artificial coal tar dye) to make it brighter and more appealing to sell. Here’s how to check for them:

• Lead Chromate: Add some turmeric powder to a glass of water and stir. Pure produces a pleasant yellow after mixing. Adulterated turmeric with lead chromate turns the water a vivid yellow rapidly.

• Metanil Yellow: Add a pinch of turmeric to a few millilitres of concentrated hydrochloric acid. The presence of metanil yellow produces a magenta or pink colour with no reaction from unadulterated turmeric.

Red Chilli Powder

It's quite easy to sneak in brick powder, red sawdust, artificial coal tar dyes (including Sudan dyes), some of which are carcinogens, and some are just abrasive. To test:

• Brick powder or sawdust: Do the water test by adding some chilli powder to a glass of water without stirring. Brick powder or sawdust will float on the surface and settle in a separate layer.

• Artificial Colour: Fill a glass with water and sprinkle a small amount of chilli powder on the surface. If an artificial colourant is present, it will immediately sink into the water in visible colour streaks.

Coriander Powder

It’s easy to camouflage sawdust and dried dung powder with coriander powder. Dried dung powder is a known carrier of microbial pathogens. To test, sprinkle coriander powder on the surface of the water in a glass. If adulterated, sawdust or bran will float on the water surface as a separate, fine layer.

Category 3: Grains and Flour

Grains are adulterated both intentionally (through mixing of inferior or inert materials) and incidentally (through improper storage, pest infestation, or fungal growth). FSSAI's DART manual covers eight separate tests for food grains and their products.

Wheat Flour (Atta)

It is quite easy to sneak in excess bran, chalk powder and fungus-infested grains into the flour. These blend in easily, but abrasive iron filings, which are also added, are easier to spot. How to detect these:

• Iron Filings: Spread a thin layer of atta on a flat and light surface. Pass a magnet over the flour. If iron filings are present, they will be zapped up by the magnet.

• Chalk Powder: Add some atta into a glass of water and mix. Chalk powder will form a solution that is visibly whiter and milkier, with insoluble residue settling at the bottom.

• Excess Bran: If your usual whole or refined wheat flour requires more water to form the dough and produces a chapati that is tasteless, excess bran is likely present.

• Fungus-infested: Look for discolourations in the beige dough, and rub the dry flour between your fingers. Ergot (fungus) infested grains, even when powdered, will be gritty.

Rice

It's difficult to tamper with rice, but in some cases, it is seen that premium rice like basmati is mixed with lower quality rice like sharbati, polishing rice, adding artificial whitening agents, or using synthetic rice.

• Added Colour: Take some rice and add it to a transparent glass of water, and give it a stir. The water will not change colour for unadulterated rice.

• Solid matter: Do a visual inspection of the rice by spreading a small quantity of it on a flat white plate. Look for tiny pebbles, seeds, damaged or discoloured grains, insect-eaten grains or anything else that has an unusual size or texture.

• Artificial Rice: Plastic rice, or rice made artificially, is easy to find by burning rice over a naked flame. The smell of plastic is quite different and unpleasant compared to burnt rice. 

Dal (Pulses)

Dal is also a victim of added colour, and certain dal varieties like arhar dal are prone to being mixed with livestock feed, like khesari dal, which can be missed if not thoroughly inspected. Khesari dal is prohibited for sale by the FSSAI as a standalone food product.

Separate any grains with a different shape from the rest of the dal. Khesari dal seeds are distinctly smaller, flatter, and more angular than arhar dal seeds. They have a wedge-like shape and can be separated and identified by visual comparison.

Category 4: Vegetables

What glitters is not always gold (it tends to be fool’s gold or pyrite), and vegetables that seem brighter than usual are most likely adulterated (artificial colouring, chemical preservation) and also prone to contamination (pesticide, waterlogging for weight). Under the FSSAI guidelines, adding colours to fresh vegetables is not permitted.

Bright green vegetables that look like they are out of a children’s picture book use malachite green and brilliant green (a synthetic dye used for bright green colour). It is a textile dye and a potential carcinogen, not approved for use in food.

To test, wash the vegetables or wipe a few leaves on a wet white cloth; if the green colour bleeds or transfers to the cloth, artificial colouring is present. Natural chlorophyll does not leech or transfer to surfaces at room temperature.

Note:  Fresh, unadulterated leafy greens have some variation in the shade of green across the leaf, with older stems being slightly yellower. Peas also tend to be a certain colour, not a vivid green. This rule also applies to other colourful vegetables such as carrots and beetroots.

Category 5: Fruits

Fruit ripening is impacted by the climate crisis, and it is no surprise that many fruit sellers increasingly rely on calcium carbide to artificially ripen fruits. The FSSAI keeps reinforcing the ban on this chemical to ripen fruit, the latest being in May 2025, directing states to crack down on the use of calcium carbide and any non-permitted fruit ripening agents. The ban also extends to adding artificial colour or wax (non-permitted) to the coating of fruits.

Mangoes, Bananas, and Papaya

Calcium carbide reacts with moisture to produce acetylene gas, which triggers rapid but uneven ripening in fruits. Mangoes, bananas and papaya tend to be under heavy carbide use. The process produces trace amounts of arsenic and phosphorus compounds, which can be harmful if ingested. Ethylene gas (up to 100 ppm, not in direct contact with the fruit) is the only permitted artificial ripening agent.

How to identify during purchase:

• Calcium carbide-ripened fruit looks uniformly coloured on the outside, but the flesh inside remains hard and under-ripe

• There may be a faint chemical or burnt smell near the stem

• The fruit softens quickly and unevenly after purchase, often rotting before ripening fully

• Tree-ripened mangoes have a sweet fragrance from the stem end. Bananas have irregular dark spots beginning to form at the tip

Note: Tap or press the fruit. Naturally ripened fruit will have even resistance, while carbide-ripened fruit often has a hard core despite looking ripe.

Apples and Cucumbers

Colour aside, these two fruits tend to have wax coatings (some of them are non-food-grade), with colours like malachite green used on cucumbers. The FSSAI permits wax coatings of bees' wax, carnauba wax, or shellac wax on fresh fruits, but requires that every package include a label indicating the type of wax used. Non-food-grade waxes, including some petroleum-based coatings, are not permitted.

To test: Firmly rub a small patch of the fruit skin with a cloth soaked in warm water with a little salt or vinegar. A greasy, waxy residue on the damp cloth indicates the use of a wax coating. Food-grade wax in normal quantities is difficult to remove by this method, but heavy or non-food-grade coatings leave a more substantial smear. For cucumbers, put them in warm water for 5 minutes, rinse well, and if it does not leech colour, then wipe on a white cloth to check. 

A Summary Reference: Common Adulterants by Category 

(Source: FSSAI DART Manual, eatrightindia.gov.in; FSSAI Regulations 2011; WHO)

What to Do if You Suspect Adulteration

If a home test produces a positive result or you suspect a product is adulterated, FSSAI provides multiple options to report the case:

• Helpline: Call 1800-11-4000 (toll-free)

• Mobile app: File a complaint via the Food Safety Connect app

• State food authority: Approach the State Food Safety Commissioner for enforcement action

• Online: complaints.fssai.gov.in

So, this World Food Safety Day, here’s a reminder to be ‘savdhan’ and ‘satark’ (careful and vigilant) and watch what you buy, for a healthier body and mind. Under the Food Safety and Standards Act 2006, penalties for food adulteration range from fines to imprisonment, depending on the severity, up to life imprisonment and fines of up to Rs 10 lakh for adulteration that causes grievous harm.