May 11, 2023: Adulterated milk is a menace. How big? What is milk adulteration and the impacts? Researchers have developed a device which can detect adulteration in 30 seconds? How does the device work? A ReferencePepper!
A cost-effective, portable, pocket-friendly 3-D device based out of paper, that can detect milk adulteration in just 30 seconds? You read that right!
Such an unconventional device has been developed by researchers at IIT Madras, that does not abide by the traditional laboratory-based rules to detect milk adulteration. The method this device deploys can be used at home with just one millilitre of the liquid sample needed for testing.
But is Milk Adulteration such a big issue? And why?
Milk adulteration poses a significant menace to public health and the integrity of the food supply chain.
Health related affects: Adulterated milk can contain harmful substances such as water, urea, detergents, starch, and other chemicals that are added to increase volume or mask poor quality. Consumption of such adulterated milk can lead to various health risks, including gastrointestinal disorders, food poisoning, allergic reactions, and long-term health problems. Vulnerable populations such as children, pregnant women, and the elderly are particularly at risk of suffering from nutritional deficiencies due to consumption of adulterated milk, which can have serious consequences on their health and well-being.
Economic afFects: Moreover, milk adulteration undermines the reputation of genuine milk producers and creates unfair competition in the dairy market. Genuine milk producers may face decreased demand for their products, lower prices, and reduced profits due to the availability of cheaper adulterated milk. This can lead to economic losses for dairy farmers and the dairy industry as a whole, affecting their livelihoods and sustainability.
Overall, milk adulteration is a serious menace that affects public health, consumer trust, and the economic viability of the dairy industry.
How bad is the Milk Adulteration menace?
As per a report by QUEEN'S UINIVERSITY, BELFAST on "food safety and fraud issues within the dairy supply chain" conducted between 2015–2019
Here's the fraudulent documentation cases from Horizonscan 2015 - 2019 relating to milk and milk products
RASSF or Rapid Alert System for Food and Feed is a system for reporting food safety issues within the European Union established which entered into force on 21 February 2002. Its objective is to achieve "a high level of protection of human life and health", based on the principle that the free movement of food and feed within the European Community (now the European Union) can only be achieved if food and feed safety requirements do not differ significantly between Member States.
How much of this menace has spread in India?
October 18 2019: The Food Safety and Standards Authority of India (FSSAI) today released the full report of the ‘National Milk Safety and Quality Survey 2018’. The survey results demolish the perception of large scale milk adulteration in the country.
The survey has shown that 12 out of 6,432 samples of milk were adulterated that render such milk unsafe for human consumption. Six samples were found adulterated with hydrogen peroxide, three with detergents, two with urea and one sample was found to have neutralizers. No samples were found with boric acid and nitrates, the other two possible adulterants. Out of 12 adulterated samples, nine were in Telangana, two from Madhya Pradesh and one from Kerala. While, there is concern, but this dispels wide spread perception that liquid milk in the country is largely adulterated.
The survey further showed that 77 (out of 6,432) samples, that 1.2 % of the samples had residues of antibiotics above the permissible limits. Amongst the top three States with highest levels of Antibiotics residues are Madhya Pradesh (23 out of 335 samples), Maharashtra (9 out of 678 samples) and UP (8 out of 729 samples). Only one raw milk sample in Kerala was found to contain pesticide residue above the permissible level.
Overall, above 93% of the samples that is 5976 (out of 6,432) samples were found to be absolutely safe for human consumption.
The above findings though shouldn't speak for the entire country as rural India and developing cities might have their own issue and covering all the cities and villages for samples is a humongous task. So, the results could vary...they could be slightly better or worse.
Back to the main article: Various components of different adulterating agents, including but not limited to detergents, soap, hydrogen peroxide, urea, starch, salt, and sodium-hydrogen-carbonate, can be easily identified by the device.
The research was led by Dr. Pallab Sinha Mahapatra, an Associate Professor in the Department of Mechanical Engineering at IIT Madras, along with Research Scholars Mr. Subhashis Patari and Dr. Priyankan Datta.
Picture source: https://home.iitm.ac.in/pallab/about.html
How does the device work?
Dr. Mahapatra stated that the technology behind their idea is the combination of microfluidics and the calorimetric reaction.
“Our device is basically an absorbent paper, consisting of micropores through which liquid can easily flow due to the capillary action. The device comprises a top and bottom cover and a sandwich structure 3D paper-based microfluidic device1", said Dr Pallab Mahapatra, in a conversation with The Better India.
A microfluidic device1 is an instrument that uses very small amounts of fluid on a microchip to do certain laboratory tests. It is also called lab-on-a-chip.
The 3D design has detection zones. Samples are added in the small opening on the top cover, and it is transferred to the detection zone through the hydrophilic channels2 due to the inherent capillary action. The chemical reaction takes place in the detection zone,” he explains.
Now, let's simply explain hydrophilic channels2 :
Imagine you have a really cool water slide at a water park. This water slide has special walls that are made of a material that water really likes, almost like the slide is best friends with water. These walls are called "hydrophilic" walls.
Now, imagine you have a toy boat that you want to send down the water slide. But the toy boat is too big to fit through the narrow opening at the top of the slide. However, there's a special part of the slide that has a wider channel, like a tunnel, that allows the toy boat to pass through easily.
That wider part of the slide is like a "hydrophilic channel." It's a pathway made of special material that water really likes, and it allows certain things, like the toy boat, to pass through easily.
In real life, hydrophilic channels are similar! They are like tunnels or passages made of special materials that water molecules really like. These channels can be found in things like cell membranes, which are the walls of cells in living things. They allow certain substances, like water or other small molecules, to pass through easily, just like the toy boat passing through the wider part of the water slide.
Hydrophilic channels are important because they help regulate what goes in and out of cells, allowing them to function properly. They are like special doors or gates that only let certain things through, and they play an important role in many biological processes.
So, just like the special walls of a water slide that water really likes, hydrophilic channels are like tunnels or passages that water molecules really like, allowing certain things to pass through easily!
“The colorimetric detection technique identifies the adulterants in these detection zones, and the adulterants can be quantified using a colour intensity test. A colour band and adulterant names are provided on the bottom cover’s backside for easy understanding of users,” he adds.
“With the provided colour bands, the number of adulterants can be measured with a limit of detection varying from 0.1% to 0.4% for different adulterants,” says Dr Mahapatra.
But results in 30 seconds? How did that happen?
Most lab tests we hear of take mostly between 6- 24 hours. So how does this device claim to deliver the milk purity results in just 30 seconds? As Dr Mahapatra explains, “The colorimetric reaction happens as soon as the sample touches the detection spot. So within a few seconds, we can get a yes or no answer.”
The design uses Whatman filter paper grade 4, which facilitates the flow of liquid and can store more reagents. Whatman filter papers are the most widely used filter paper for routine laboratory applications, qualitative analytical separations, and clarifying liquids.
Milk is one of the most fundamental food items for maintaining a healthy lifestyle, bone development, and also serves as a part of children’s diet. However, it is also one of the most commonly adulterated food items worldwide, particularly in countries like India, Pakistan, China, and Brazil.