In Conversation with a Scientist Who Detects Milk Adulteration

A pioneering testing method has been successfully developed to identify tampered camel milk, in the face of rising demand and escalating instances of adulteration by Dr. Sanay Naha. This innovative solution from Tripura State Forensic Science Laboratory addresses a critical concern in the dairy industry, safeguarding consumers against fraudulent products.

 

Q1. What Inspired you to create a test to detect fake or tampered camel milk?

Ans: According to the FCC (Food Chemicals Codex) in the United States pharmacopeia, conventional milk and dairy products account for 18% of all adulteration cases, placing milk and dairy adulteration in the second position. From an Indian perspective, our long-standing connection with camels and their products has become integral to our culture. We export camel milk and its derivatives. Research indicates that camel milk is a nutritionally dense food source, containing essential components such as proteins, carbohydrates, vitamins, minerals, and fats, making it a strong alternative to human breastmilk. Recently, the demand and consumption of camel milk have surged dramatically, leading to increased instances of adulteration. This is why me and my collaborator, Dr. Rakesh Ranjan, a scientist at ICAR-National Research Centre on Camel in Bikaner, has undertaken this issue.

Q2. How does your test work, and what makes it unique?

Ans: The technique developed was focused on amplifying the Cytochrome b gene using multiplex PCR to identify the adulteration of camel milk with milk from cattle and goats.

Q3. What was the biggest challenge you faced while developing this test and how did you overcome it?

Ans: Milk adulteration includes a variety of fraudulent practices, such as the replacement of milk fat or protein, the substitution of higher-value types of milk with those of lower value, dilution, the addition of fillers and preservatives, whey rennet, undisclosed processing techniques, and mislabeling of origin. One of the most prevalent forms of this deception is the replacement of sheep's, goat's, or camel's milk with cow's milk. Since the substitute milk is generally non-toxic and similar, it can be quite difficult to distinguish between their quality and quantity. Among the many methods we explored, identifying the genomic sequences proved to be a significant factor in differentiating camel milk from other types of milk.

Q4. Can you explain how you ensured that your test is accurate and reliable?

Ans: PCR (Polymerase chain reaction) technology is widely recognized for its ability to identify genomic sequences or small gene segments through amplification, and it has been utilized for disease diagnosis; for example, during the coronavirus pandemic, RT-PCR proved invaluable in detecting infected individuals. We have implemented a novel approach known as multiplex PCR. When comparing the results we obtained with those from individual datasets, we discovered that our method can detect multiple components in a single run.

Q5. How sensitive is your test and can it detect even small amounts of fake or tampered milk?

Ans: The sensitivity of the methods was evaluated only for two species (cow milk and goat milk) which are 10% and 5%, respectively.

Q6. What are the practical applications of your test and how can it be used in real-life situations?

Ans: The improved method is especially beneficial for the immediate quality assessment of raw milk from any breed, forensic testing of dairy products, and particularly for verifying camel milk authenticity. This technique can be applied to the milk of other animal species as well. A small quantity of milk should be placed into the sample holder, and the instrument should be operated according to the optimized standard operating procedure (SOP). By analyzing the results from Agarose gel electrophoresis, we can determine the presence of milk from other species and measure its quantity.

Q7. How does your test compare to other methods of detecting fake or tampered milk?

Ans: Contamination of milk has been documented in various forms, including the addition of fillers, preservatives, whey rennet, and undisclosed processing techniques. In these instances, milk is tainted with foreign substances that are not naturally part of it. Therefore, the existing methods are specifically designed to detect these unusual components. However, blending milk from different species is distinct from the aforementioned forms of adulteration. Thus, drawing comparisons with other methodologies is not entirely accurate in this case. Nonetheless, the results are quite commendable.

Q8. Are there any limitations or challenges associated with using your test and how can they be addressed?

Ans: This approach is specifically tailored for camel, goat, and cow milk. It should also be adapted for other species. Additionally, the operation cost and the operational knowledge level are crucial for implementing this method. There is a need to streamline the operational process and reduce it to a tool.

Q9. Can you explain how your test can help protect consumers from fake or tampered milk?

Ans: Once the methodology is applied as the PoC tool, it can be used to assess the purity of milk at the moment of purchase. Therefore, anyone can determine the purity of the milk.

Q10. What’s next for your research and how do you see your test being used in the future? 

Ans: Our subsequent action will involve refining the method to enhance accuracy to the greatest extent. Additionally, we aim to develop the method into a Proof of Concept tool for broader applicability.