Milk has been an integral part of Indian food culture as it contains essential micronutrients. However, can we ensure that the milk we all consume daily is pure and free from harmful chemicals? We often come across news reports related to milk adulteration from across the country, which certainly raises concerns about the purity standards of milk. Various chemical adulterations in milk can lead to health problems like heart diseases, diarrhea, central nervous system disorders, and even cancer.
The demand for milk and dairy products is high today. Taking advantage of this, some milk traders produce fake milk (synthetic milk) that looks exactly like real milk, and everyday consumers end up buying milk, about which they have no idea whether its pure milk or synthetic one. Synthetic milk is generally prepared from a mixture of detergent, ordinary vegetable oil, urea, and normal tap water. With this chemical mixture, milk is often made creamy (fat-rich) and efficient (protein-rich), giving it the appearance of high quality.
RESEARCH BY BHU
A team of researchers from the Banaras Hindu University & Sikkim University has developed a new, cost-effective, and home-based method for detecting adulterants in milk using the evaporation process and machine learning algorithm. The method is useful in ensuring the strength and quality of milk and public health. The method has been developed by Tapan Parsian, a research scholar, under the supervision of Dr Archana Tiwari, Department of Physics, in collaboration with Dr Ajay Tripathi, Sikkim University.
The evaporation process is a phenomenon in which, when a drop is left to evaporate on a surface, the suspended particles in the drop move towards the edges and leave behind a ring-like pattern on the surface. Different types of suspended particles form their own unique evaporated ring patterns. These evaporated ring patterns act as fingerprints for identifying the substance.
To validate the method, synthetic milk was prepared in the lab by mixing appropriate amounts of detergent, ordinary vegetable oil, urea, and tap water to create a mixture that resembled real milk. This synthetic milk was then mixed with real milk in varying quantities. The evaporated ring patterns of the synthetic milk were then analysed.
During the analysis, several signs were identified in the evaporated ring patterns that reveal the quality of the milk. Synthetic milk evaporation patterns exhibit multiple rings, visible micro-droplets of vegetable oil, and varying degrees of transparency, which can provide insights into the extent of adulteration in pure milk. If the evaporated patterns are highly transparent, it indicates a higher proportion of synthetic milk adulteration.
Conversely, if the patterns are less transparent, it suggests a lower presence of synthetic milk.
HOW TO TEST AT HOME?
This method provides a simple home-based approach for milk quality assessment. Using a medical syringe, place a drop of milk on a glass slide and allow it to evaporate. Capture an image of the evaporated patterns using a smartphone camera. If the signs mentioned above are present in the evaporated patterns on the glass slide, it confirms the adulteration of milk with synthetic milk.
During the experiment, for large-scale analysis, the water and synthetic milk mixed evaporated ring patterns were used to train and validate the machine-learning model. During the experiment, the model detected pure and synthetic milk with 96.7 percent accuracy and water-mixed milk with 95.8 percent accuracy.
