1Department of Agricultural Engineering, Birsa Agricultural University, Ranchi-834006
2Department of Food Engineering, Faculty of Agricultural Engineering, BCKVV, Nadia-741252
3Agricultural and Food Engineering Department, Indian Institute of Technology, Kharagpur-721302
*Corresponding author's E-mail: irfan26200@yahoo.com
Online published on 2 January, 2019.
UHT treatment of milk is a novel technology, which gives a product of better bacteriological and organoleptic qualities. A small scale helical triple tube UHT milk sterilizer having capacity of 135 l/h with all necessary instrumentation was developed and tested for performance. In heating section, the preheated milk at 90°C was heated to sterilization temperature of 150°C, then held for 3 seconds at the same temperature in holding section to achieve the desired degree of sterility followed by cooling in cooling section to 90°C. The performance of the helical triple tube UHT milk sterilizer was found satisfactory, since the UHT milk was bacteriologically safe and free from drastic colour change and gelation (due to progressive rise in viscosity) for about two months under ambient storage condition. The unit is low cost, simple in operation, easy in cleaning and sterilization, high heat transfer area per unit length, minimum fouling problem, high turbulence, less floor area requirement, minimum water requirements, etc. These features make it very suitable for rural dairy cooperatives.
UHT, Sterilizer, Gelation, Minimum fouling, Dairy co operatives
