The Scale of the Problem
Milk adulteration is a significant and long-standing issue in India. The practice involves deliberately adding substances to increase volume, extend shelf life, or mimic the natural consistency and richness of pure milk. Studies by the Food Safety and Standards
Authority of India (FSSAI) have previously revealed that a large percentage of milk samples across the country do not conform to safety standards. The most common adulterant is water, which not only reduces the nutritional value of the milk but can also introduce harmful contaminants if it is not potable. Beyond water, other more dangerous substances are also used, making vigilance crucial for consumers.
Common Adulterants and Their Risks
The substances added to milk range from simple diluents to hazardous chemicals. Common adulterants include starch, urea, and even detergent. Starch is added to prevent curdling and restore thickness to diluted milk. Detergent is used to create a frothy, rich appearance in milk that has been watered down. Urea, a component of fertiliser, is sometimes added to artificially boost protein readings. Consuming these adulterants can lead to serious health issues. Detergents can cause food poisoning and gastrointestinal complications, while urea and other chemicals can put a strain on the kidneys and have more severe long-term effects.
How to Test for Water
The simplest and most common form of adulteration is dilution with water. Luckily, it is also one of the easiest to check for at home with what is known as the slope test. Take a polished, slanted surface, like the back of a steel plate (thali) or a clean tray. Place a single drop of milk at the top. Pure, unadulterated milk will flow slowly and leave a distinct, white trail behind it. Milk that has been mixed with water will flow down quickly and leave almost no mark, appearing much more transparent.
Detecting Starch and Detergent
To check for starch, you'll need tincture of iodine, which is readily available at most pharmacies. Take a small sample of milk, boil it briefly, and let it cool. Add two to three drops of the iodine solution. If the milk turns blue, it indicates the presence of starch. For detecting detergent, the test is even simpler. Take about 5-10 ml of milk in a small, lidded bottle or glass and shake it vigorously for about 30 seconds. If a dense, stable lather or foam forms, similar to soap bubbles, it is a sign that the milk may be adulterated with detergent. Pure milk will only form a thin layer of foam that disappears quickly.
Checking for Urea
Urea is a more dangerous adulterant, but a simple test can help flag its presence. Take about 5 ml of milk in a test tube or small glass. Add an equal amount of soybean or arhar dal powder to it and shake the mixture well. Let it stand for five minutes. After five minutes, dip a strip of red litmus paper into the mixture. If the milk is pure, the red litmus paper will remain red. If it turns blue, it indicates the presence of urea.
Smart Storage for Maximum Freshness
Beyond adulteration, improper storage is a primary cause of milk spoilage, especially in warmer climates. Bacteria multiply rapidly at room temperature. The golden rule is to keep milk refrigerated at or below 4°C. It's best to store milk on the middle or bottom shelves of the refrigerator, where the temperature is most consistent, rather than in the door, where temperatures fluctuate with frequent opening and closing. For raw milk from a local vendor, it is essential to bring it to a rolling boil soon after purchase to kill any bacteria, then cool it and refrigerate immediately.
Best Practices for Handling Milk
A few good habits can significantly extend the life and safety of your milk. Always ensure the milk container is sealed tightly, as milk can easily absorb odours from other foods in the fridge. Use clean, dry utensils when pouring milk to avoid introducing bacteria. It's also a good practice not to mix fresh milk with an older batch, as this can cause the new milk to spoil faster. Finally, always check the expiration or 'best before' date on packaged milk before purchasing and consuming it.
