Milk is the most common drink in morning breakfast of major households in India. It is one of the healthiest drink and a must for every individual, especially for kids and children. But most of the time the milk we drink is not pure. AduIteration of milk is the common problem in all parts of the country. The things which generally adds in milk are water, urea, starch, Vanaspati etc. Even the packaged milk from reputed companies contain one or another adulteration in milk which causes the negative effect on human body. Therefore it is always advisable to check the purity of milk before drinking it. There are a number of ways through which you can test the purity of milk. Here is the list of few simple and convenient methods to check the purity level in milk at home.
Method 1. Reduction Test
- To test the purity of milk using reduction test, first, you need to take the milk in a flask.
- Boil this milk at low temperature for the long duration of time i.e. around 2-3 hours until it becomes solidifies. This solidifies milk is called khoya.
- If the solidifies milk is very hard like rock solid and rough then it means milk is not pure and contain some sort of adulteration while if khoya is oily then it is a good quality of milk.
Method 2. Test for Synthetic Milk
Synthetic milk is formed by mixing various chemicals and other things like soap in pure natural milk.
- Take the small quantity of milk in a glass and taste it. If it is bad in taste then it means it contains some chemicals.
- Heat the small quantity of milk in a flask, the synthetic milk changes its color from white to yellowish. Moreover, if you rubbed the synthetic milk on hand, it feels soapy in nature.
Method 3. To test water in Milk
Water is the most common thing that can be added to milk because it is free of cost. Though the addition of water is not bad for human health but it does not good for your wallet. To check the water impurity in milk, put the drop of milk on any inclined or slanted surface and let it flows freely. If the milk leaves any kind of tail behind then it means it contains water in it.
Method 4. Test of Vanaspati/Dalda in Milk
Vanaspati is also added in milk to make it impure, but intake of Vanaspati or Dalda is not good for health if consumed more than the prescribed limit. To check whether the milk is adulterated with Vanaspati, Mix 1 teaspoon of milk with 1 teaspoon of sugar and 2 teaspoons of Hydrochloric Acid (HCL) and kept it idle. If this mixture turns it color to red then it means it contains Vanaspati.
Method 5. Starch in Milk
Milk vendor also add starch in milk to make it adulterated. If you want to test the presence of starch in milk, take 5 ml of milk and add 2 teaspoons of common salt (iodine) in it and kept it idle. If this mixture turns blue in color then it means milk is adulterated with starch otherwise if it remains intact then it is pure milk without starch content in it.
Method 6. Formalin in Milk
Formalin is used for preservation. It is transparent in color and can preserve the milk for the long duration of time, the company’s manufacturing packaged milk added it in the milk. To test the presence of Formalin in milk, take 10 ml of milk in the test tube and added few drops of sulphuric acid in it. If the blue ring forms at the top of the test tube then it means milk contain formalin otherwise milk is pure.
Method 7. Test for Urea in Milk
The addition of Urea is the second most common form of adulteration in milk apart from water. It is difficult to test the presence of urea in milk since it doesn’t change the taste of the milk.
- To test whether the milk contains Urea or not, you need to take 1 teaspoon of milk and mix with little amount of soyabean or arhar powder
- After this, shake the mixture and kept idle for 5 minutes.
- After 5 minutes, dip the litmus paper in the solution. If the litmus paper turns from red to blue color then it means milk contain urea in it.
As per the study conducted, around 70% of the milk sold in India contain one or other form of adulteration. Though the Government is very serious and strict towards any kind of adulteration in eating products but due to loopholes in our system, milk adulteration is most common. It is the duty of citizens also to check the purity of milk before consuming it. You can use any of the test described above to test the purity of the milk.