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