Milk has always been an indispensable and inseparable part of people’s food regimes. Milk and milk products, regardless of age, never fail to provide much-needed comfort after a long, exhausting day. So, it becomes crucial to ensure that milk is safe for consumption. That is when microbial analysis of milk and milk products comes in handy.

We can never be completely sure that the milk we are consuming daily is pure and free from hazardous chemicals. But, with the in-depth analysis in our laboratory, you can have a broad idea before you consume adulterated milk.

Before we delve into the analysis, let’s revolve a tad around milk adulteration and contamination.

What is Milk Adulteration?

When manufacturers deliberately degrade milk quality, either by removing a valuable ingredient or by adding some inferior substances, the process is known as milk adulteration. This is typically done to increase the quantity of milk and make huge profits illegally.
Adulterated milk is harmful to consume as it is devoid of nutrients essential for growth and development.

The Difference Between Contamination & Adulteration: 
You might think that contamination and adulteration can be used interchangeably. However, that is so not the case. Sure, they both negatively affect the quality, and both shouldn’t be tolerated, but they have quite a significant difference.

Contamination of Milk:
Substances are added to the milk unintentionally, thereby decreasing the milk quality. Environmental contamination and bad handling practises are a plethora of reasons for contamination.

It can even happen if the milk is not stored properly or there are quality issues related to its supply chain management.

Milk Adulteration:
Unlike contamination, adulteration is intentional. It is often done to degrade the quality and make money illegally. This process poses serious health hazards. Adding water, detergent, and other harmful chemicals are some of the most common adulteration techniques.

Let’s study a few typical milk adulterants in detail:

  • You might find it a tad surprising that table sugar is added as an adulterant to increase carbohydrate content and milk density. Consequently, water is added to the milk that cannot be detected with a lactometer test.
  • To increase the shelf life of milk, benzoic acid and salicylic acid are added to increase the shelf life of milk.
  • Starch is added to the milk to increase the solid content.
  • Soap is added to milk to make it thick. Consuming such milk leads to severe health issues related to the stomach and kidneys.
  • Formalin is added to milk to preserve it for a long period of time. It is also highly toxic and can be damaging to the liver and the kidneys.
  • As ammonium sulphate has the tendency to increase the lactometer reading by maintaining the density of milk, ammonium sulphate is quite commonly used as an adulterant in milk.

Methods to Check Adulteration in Milk at Home:
Here is a list of tests that individuals can conduct at home to check for impurities-

Test for checking the presence of water in milk
To conduct the test, all you need to do is put a drop of milk on any slanted surface. If the milk flows quickly, it proves that it contains water. Pure milk will flow slowly, leaving a trace behind. Adulterated milk will never leave a mark behind.

Test to Check the Presence of Urea in Milk
Urea is one of the most common adulterants merchants use to make milk impure. The troubling thing is that urea does not change its taste and is quite hard to detect. Therefore, to detect the presence of urea, you need to mix a tablespoon of milk with soya bean powder and shake the mixture well.

Next, you must dip a litmus paper in blue dye and check whether the colour changes from red to blue. And, if it does, the sample has urea in it.

Analysis of Milk—How can Adulteration be Detected?
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The Test for Synthetic Milk
You can easily detect synthetic milk by sniffing it. Synthetic milk typically tends to have a bad taste and odor. You can even perceive a soapy smell and feel soapy when rubbing it with your hands.
If you feel the presence of synthetic milk in your daily dose of milk, you better bring it to us. Lab testing is required to ensure urea’s presence.

Laboratory Methods to Test Milk for Adulteration test for the detection of formalin.

This procedure involves our lab technicians taking a test tube and adding 10 ml of milk. Then, we slowly pour concentrated formalin from the side of the test tube wall. We make sure that the acid is poured very cautiously without shaking it.

We’ll know that formalin is present in the milk if the mixture forms a red or violet ring at the meeting point of two layers.

Test for the detection of hydrogen peroxide
When we are conducting a milk adulteration lab test to specifically defect Hydrogen Peroxide, we will take a test tube and pour 5 ml of Silver Nitrate reagent, 3 drops of Paraphenylene Diamine. We will then shake the mixture thoroughly.

You know the milk contains hydrogen peroxide if the colour changes to blue. We can also do this with a different method. We pour 10 ml of milk into a test tube and add Vanadium Pentoxide reagent, measuring 10-15 drops. If the colour changes to pink or red, hydrogen peroxide is present.

Test for the detection of boric acid
Our lab technicians will take 3 ml of milk in a test tube and add 20 drops of HCL. We will then shake the mixture thoroughly. We’ll then add a paper strip of yellow colour and leave it for 1 minute. If it changes colour from red to yellow to green, it indicates the presence of boric acid.

Test for detection of chemical parameters
The team of chemists is well trained for analysis of multiple parameters in milk and milk products like proximate analysis, pesticide residues, minerals & metals, fatty acid profiling, adulteration tests, nutritional profiling and many more.

Wrapping it Up
When it comes to the microbiological analysis of milk and milk products, our labs are well-equipped. Our easy detection methods are easy to conduct in the laboratory and can prevent you from consuming harmful products

If you have any queries or are thinking of getting milk tested before taking on a new project, feel free to get in touch with us.