Pakistan is the 5th largest producer of milk in the world. Milk is predominantly produced in small units largely in the far flung rural areas. Because of its perishable nature and traditional unhygienic handling practices, many a times it gets spoiled, particularly in the summer season. To avoid spoilage milk, collectors/haulers use different chemicals or add ice to keep its
temperature down. Under natural climatic conditions of the country, the collection, transportation and safe distribution of milk to consumers is a challenging task, the best solution to which is to develop and maintain cold-chain milk collection system. In the absence of this facility, an alternate milk preservation method is thus highly desirable.
Lactoperoxidase System (LPS) is a naturally occurring chemical complex in raw milk that keeps bacterial multiplication arrested (bacteriostatic effect) but hardly for 2 to 3 hours after milking. This effect can be enhanced upto 8 to12 hours by further activation of LPS. The technology uses sodium / potassium salts of thiocyanate and hydrogen peroxide in extremely minute quantities. The recommended dosage is usually between 15 to 30 ppm (0.0015 to 0.0030 %) of each of these additives. These are added one after another in a specific order to raw milk within two hours of milking. The thiocyanate is added first, the milk is stirred and then hydrogen peroxide is added and the milk is again stirred. Ready-to-use doses can be made available from the Dairy Technology Program. Addition of these additives activates the natural LPS in raw milk and effectively preserves the milk for about 8 to 12 hours (depending upon initial bacterial load and storage conditions) even under hot and humid season.
This technology has been widely tested in Pakistan under local conditions and has been found equally good both for cow and buffalo milk. The technology has been demonstrated and successfully transferred to certain milk pockets (Sargodha Division) to collect raw milk for small and medium dairy processors. Similarly, field trials and practical demonstrations have been undertaken in all the provinces. Utilization of LPS can be very effective to combat menace of chemical adulteration, thereby assuring the supply of good quality milk for processors/consumers in places where cold chain facilities are not available. This is also recommended by WHO/FAO for countries/areas where cold chain facilities are not available.
Key Reference
Athar, I. H., M. S. Bhatti and M.A. Shah. (1996). Preservation of raw milk through activation of lactoperoxidase system (LPS). Journal of Food Science. 6(1-2): 9-11.
