Portable Device to Detect Adulteration in Milk | 13 May 2020

Why in News

Recently, researchers at the Indian Institute of Science (IISc), Bengaluru have developed a low-cost device to detect the presence of melamine (adulterate) in milk and dairy products.

Key Points

• The techniques currently used to detect the presence of melamine are time-taking and typically require expensive and sophisticated equipment and highly trained personnel.
• With the help of a newly developed fluorometer device
  
  • Researchers were able to detect up to 0.1 parts per million (ppm) of melamine in water and milk, which is much lower than the acceptable limit of 1 ppm.
  • The detection also took just four minutes.
• Functioning:
  
  • Copper nanoparticles are added to the specified DNA (double stranded) template of the milk and the sample is tested using the fluorometer.
  • Researchers observed that the presence of melamine in the sample disrupted the synthesis of copper nanoparticles on double stranded DNA and caused a reduction in the intensity of fluorescence, which was detected by the fluorometer.
    
    • These copper nanoparticles possess a property called fluorescence in which a material emits light of a different wavelength (colour) when a particular wavelength of light falls on it.
• Fluorometer:
  
  • It is a device used to measure parameters of visible spectrum fluorescence i.e. intensity and wavelength.
  • These parameters are used to identify the presence and the amount of specific molecules in a medium. E.g
    
    • The fluorometer can be used to detect biomolecules and proteins using the copper nanoparticles.
    • The device can also be modified to detect other substances such as lead and mercury.
  • Fluorometer can also be deployed as a screening tool for environmental and food quality testing.
• Earlier, Food Safety and Standards Authority of India (FSSAI) had imposed a ban on all milk and milk products from China in September 2008.
  
  • In April 2019, FSSAI had recommended the extension of the ongoing ban till labs at Indian ports are equipped for melamine testing.
• India is the world’s largest producer and consumer of milk.

Melamine

• Melamine is an organic base chemical most commonly found in the form of white crystals rich in nitrogen.
• It is widely used in plastics, adhesives, countertops, dishware, whiteboards.
• Used as adulterate:
  
  • To increase milk volume, water is added, as a result of this dilution the milk has a lower protein concentration.
  • Companies normally check the protein level through a test measuring nitrogen content.
  • The addition of melamine increases the nitrogen content of the milk and therefore its apparent protein content.
• Melamine poisoning can lead to kidney-related diseases and also kidney failure.

Source: IE