Fresh Milk vs. UHT Milk
Difference Between Fresh Milk And UHT Milk
Fresh milk is the milk which is pasteurized at a temperature of 72 ° C for about 15 seconds. This is done within 48 hours of milking. On the other hand the UHT milk undergoes a treatment at high temperature, generally 135-150 ° C for about 1-5 seconds. This allows it to be stored at room temperature for a period of 3-6 months, while fresh milk must be refrigerated at 4 ° C for no more than 6 days.
The fresh milk undergoes the treatment of pasteurization within 48 hours of milking. The process involves heating the milk at a temperature of 72 ° C for a period of only 15 seconds. This treatment preserves the nutritional properties of milk intact, and at the same time allows you to kill about 96% of bacteria. The remaining 4% of the bacteria is made up of spores which have become heat resistant. To slow the growth of the latter, the milk is immediately cooled to 4 ° C. With heat treatment at high temperatures sometimes causes denaturation of protein, or killing them. The fresh pasteurized milk has a content of serum Protein. It has a slightly higher percentage (about 10% more) of thermolabile Vitamins than the milk which undergoes heat treatment. As for the deadline, the fresh milk must be stored in a refrigerator at 4 ° C and consumed within 6 days by heat treatment immediately.
The UHT milk undergoes an ultra high temperature, which, in fact, is a particular technique of sterilization which makes the milk subjected to Homogenization. In this process milk is passed through the process of preheated to a proceeding heating. It requires the use of temperatures of at least 135 ° C (Up to 140-150 ° C) for a time period between 1-5 seconds. Subsequently, the milk is cooled 15-20 ° C and undergoes packaging and sealing in sterile containers. So Sterile milk from commercial point of view means the milk without microorganisms, but it does not guarantee the destruction of more resistant spores. From the nutritional point of view, UHT milk has a slightly lower rate of Vitamins compared to fresh milk.