Ludhiana-19-Jan, 2012 : Various types of adulterants are used for adulterating milk to get extra profit by unscrupulous persons. There is a long list of adulterants for example, sugar, starch, glucose, malto-dextrin, salt, urea, ammoniac fertilizers, sodium carbonate & bicarbonate, sodium hydroxide, hydrogen peroxide, formalin, detergents, vegetable oils, mineral oil, etc and many more. The information was shared by Dr. Amit Kumar, College of Dairy Science & Technology of Guru Angad Dev Veterinary & Animal Sciences University, Ludhiana. He said that the adulteration of milk is usually done for increasing the quantity of milk, extending shelf-life, maintaining SNF (Solid not Fat) and avoiding detection of sour milk. With the advent of a new adulterant, laboratory methods of their detection has also been developed and used in checking the particular adulterant present in the milk. The laboratory methods have been further made simpler and converted into the kit form by different organization including National Dairy Research Institute, Karnal. Now-a-days, kit for rapidly detecting adulteration in milk is available in market for 5, 14 and 20 adulterants (marketed by National Dairy Development Board). Depending up on the need one can buy a kit and easily detect the adulterants present in milk.
Dr. Amit said that recently reports came in a larger section of the news papers telling about the extent of adulteration in milk in various states of the country. As per national survey on milk adulteration 2011 conducted by Food safety and standards authority of India (FSSA), it was reported that 81%, 70% & 83% of the milk samples was found adulterated in Punjab, Haryana and J&K, respectively. Water, Glucose and SMP (skim milk powder) was reported to be present as adulterant, especially, in loose milk which is mostly done at the level of middleman. This might be done to increase the quantity of milk by adding water and then to maintain the standards, glucose and SMP may be added. Here, it may be noted that even natural milk does not confirm the FSSA standards of SNF content (minimum 8.5%), so to maintain the standards many milk processing units also add some SMP in milk. In India, 16-18% of total milk is handled by organized sector out of which about 46% is processed as liquid milk which are available in four variants namely- double tonned milk, tonned milk, standardized milk and full cream milk having 1.5, 3.0, 4.5 and 6.0% fat, respectively.
Dr. Pranav Kumar of the same College revealed that reported adulterants can be easily checked at laboratory and/or collection center. Addition of water decreases the density of milk which can be detected by taking lactometer reading. If the reading is less than 28, milk must be said to be adulterated with water. Glucose adulteration may be checked by simply using various kits available in the market. SMP may be detected by observing the color on dissolving the residues obtained after centrifugation of 50 ml milk in 2.5 ml concentrated nitric acid followed by addition of 5 ml distilled water and 2.5 ml of liquid ammonia. Orange/yellow color development confirms the addition of SMP in the sample.
Therefore, most of the reported and un-reported adulterants can be checked through kit method or by following the simple methods at chilling center, dairy plant or even at home at nominal cost Dr. Pranav added. One can get training to check adulteration in milk by rapid method at domestic level at College of Dairy Science and Technology. Phone No. of College is 0161-2553308. However, published report is overwhelming as no harmful adulterant has been reported in the survey but still there is need to stop adulteration in milk.
