Milk is one of the most important food items most of us cannot do without. From infants to elderly people, growing children and adults, women and men, milk is a vital source of energy and food for all of us.
It is therefore disheartening to know that milk is one of the most adulterated food items in the world, especially in developing nations like India, Pakistan, China, and Brazil. The consumption of adulterated milk can lead to serious problems such as kidney problems, infant death, gastrointestinal complications, diarrhoea, and even cancer. Thus testing the purity of milk is very important.
The usual methods to test the purity of milk include lactometer density test, high-performance liquid chromatography (HPLC), infrared spectroscopy, and many others. However, these tests are lab based and are costly and time-consuming.
In this study, the authors which include Mr. Subhashis Patari, Dr. Priyankan Datta, and Prof. Pallab Sinha Mahapatra from the Micro Nano Bio-Fluids Group, Department of Mechanical Engineering, Indian Institute of Technology (IIT) Madras, Chennai, India, have developed a novel low-cost method to test the purity of milk.
They have used a three-dimensional, paper-based portable device to detect different adulterants in milk samples based on the colorimetric technique.
The adulterants chosen for this study included urea, detergents, soap, starch, hydrogen peroxide, sodium-hydrogen-carbonate, and salt.
Only 1 to 2 millilitres of sample is required for each test, and the result is known in less than 30 seconds. The cost of testing for adulterants is also very less. This lightweight, low-cost, simple-to-use, environmentally friendly method can also be used to inspect other liquid foods such as water, protein shakes, fruit juices, etc.
In the future, the authors hope that this method can also be used for mobile application to perform quantitative analysis to determine the adulterants’ concentration.
Prof. Soumyadip Sett, from the Department of Mechanical Engineering, Indian Institute of Technology (IIT) Gandhinagar, Gandhinagar, India, acknowledged the problem of milk adulteration in India with the following comments: “Milk adulteration is a prevalent problem in India, with the Food Safety and Standards Authority of India (FSSAI) stating more than 70% of tested milk samples not conforming to the standards. One of the biggest challenges is the wide variety of chemical contaminants that can be present in adulterated milk.”
He goes on to praise the efforts of Prof. Pallab Sinha Mahapatra and his team by stating the following: “This article by Prof. Pallab Sinha Mahapatra and his team has developed a unique microfluidic paper-based device that can detect 7 adulterants simultaneously from a very small sample volume of ~1 mL. Ranging from harmful chemicals such as urea, hydrogen peroxide, starch to common detergents, soap, and salt, the device can quantify the extent of adulteration through difference in color intensities with minimal interference when multiple adulterants are present simultaneously.” He concludes by stating the advantages of the method developed by the authors of this paper to test the purity of milk: “Moreover, the detection limit of 0.05% – 2% (v/v) makes this novel 3D microfluidic paper-based platform not only inexpensive and easy to use as a portable device for identifying adulterants, but can be utilized to determine if the milk sample is according to FSSAI standards. The developed solution proposed in this work significantly contributes towards sustainable, low-cost systems necessary to ensure liquid food safety in remote areas of developing countries.”
Article by Akshay Anantharaman
Here is the original link to the paper:
https://www.nature.com/articles/s41598-022-17851-3
