Now You Can find Milk Quality and freshness, Technology given by IIT Guwati

Milk is a good source of  Fat and Protein, we consume in our daily life. We get milk either by dairies, and packets. But we can not find the milk is fresh and what is its quality. So here is a technology which tells you about the milk quality.

The milk quality and freshness can be found by Simple paper kit and a smartphone app developed by Scientists at the Indian Institute of Technology (IIT), Guwahati. This kit will let us know that milk should be consumed before it turns too sour.

Why we should test Milk Quality?

Being a rich source of protein and fat it is highly consumed food in our country.  we must make in our concern that it is safe or not to take as food. Milk is a byproduct obtained from an animal, so it is highly prone to come in an action of enzymes and microorganisms which is present in it. We use techniques for preserving Milk that is pasteurization, freezing but there is no easy way to know if milk is fresh or stale or how effective is the pasteurization.

 Pasteurization:  partial sterilization of a substance and especially a liquid (such as milk) at a temperature and for a period of exposure that destroys objectionable organisms without major chemical alteration of the substance

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How does this work?

A milk enzyme, Alkaline Phosphatase (ALP), is considered to be an indicator of milk quality The alkaline phosphatase (ALP) is an enzyme normally present in raw milk and it is inactivated in conditions of heat treatment. So the ALP test in pasteurized milk is used to verify if the heating process of pasteurization is done correctly because its presence even after pasteurization indicates the presence of microbes that may not have been rendered inactive with pasteurization.

  • Researchers used ordinary filter paper to prepare the detector.
  • The filter paper was cut into small discs using office punch and impregnated with chemical probes that preferentially react with ALP.
  •  The ‘probes’ used are antibodies that specifically bind to ALP.
  • When ALP comes into contact with the probe, it turns white paper disc into a coloured one.

How color of the paper change?

The paper was chemically soaked with 4-carboxybenzene diazonium solution then chemically treated to expose-COOH groups on the diazonium.The -COOH groups then attach to NH2 groups on anti-ALP probe molecules. Thus the anti-ALP probes are fixed on paper. When a drop of milk is poured on the tiny paper disc, the ALP in milk reacts with probes, resulting in change of colour.

How the change in color show the quality of milk?

The change of color on the paper then analyzied by application. This color change is  photographed by a smartphone camera and then images are processed to obtain corresponding colour values.The values are compared with the standard data. Thus it can check not only the amount of ALP present bu also the amount of milk particles and its freshness.

This is also a matter of conern that the color change is not because of the Vitamins, Well they justified in their researches. The color change is only due to ALP and not due to the interference of vitamins, other proteins and minerals in the milk.


It is too simple that anyone can use this strip without help.The sensor works in both qualitative and quantitative modes. The kit could come handy in

  • It can tilize in milk bars,
  • In large kitchens
  • And milk collection centres where freshness of milk is a concern.

Tests used in dairies and dairy industries are time-consuming and need sophisticated equipment like spectrophotometers. The new detection kit could make testing easy and fast.


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