The Indian Institute of Technology, Guwahati developed a paper-based sensor that can make assessment of the freshness of milk by a simple method and instantaneous.
Daily Current Affairs Quiz 2019
Bacteria and other microbes that can grow in milk can not only affect the taste and freshness, but can also result in health issues. Pasteurisation is commonly used to kill the microbes in milk and various tests are used to ensure the effectiveness of pasteurisation. Commonly used tests such as the methylene blue test, are time consuming; it could take many hours for colour changes to indicate presence and absence of microbes.
Alkaline Phosphatase (ALP) is a metalloprotein found naturally in raw milk samples and is considered an important biomarker in quality control of milk. It is found in raw milk and is destroyed during pasteurisation. The researchers have used simple filter paper, chemically modified it, and loaded it with a recognition element anti-ALP, which captures the ALP present in the milk.
The sensor takes merely 13 min to detect ALP, and hence it can be applied for quick onsite analysis. The researchers successfully tested milk obtained from villages and commercially available milk samples using their paper-based sensor kit, and found that they could detect down to 0.87 units of ALP per millilitre of milk to about 91-100 per cent accuracy.
