Ultra-high temperature sterilized milk adopts high temperature instantaneous sterilization technology to eliminate all bacteria and spores in milk, and can be stored for 9- 12 months at room temperature. However, the normal temperature milk is kept at about 30℃ after instantaneous sterilization at ultra-high temperature, and the shelf life is only 1-2 days.
Except ultra-high temperature sterilized milk, the shelf life of normal temperature milk is short, mostly around 1-7 days, and it needs to be drunk within 1-2 days. The shelf life of boxed milk is generally 1-6 months, while the shelf life of milk packaged by Tetra Pak is shorter, generally about 6 months.
UHT ultra-high temperature sterilized milk needs fresh and high quality milk source. After entering the production workshop, the unique process of pretreatment should be carried out first. Raw milk is heated to 75℃ in a sealed pipeline in order to activate bacteria in milk, and then ultra-high temperature sterilization is used, which can greatly improve the effect.
Because if milk is sterile, the number of bacteria per milliliter of raw milk before ultra-high temperature sterilization should not exceed 30 thousand, which has actually reached the standard of pasteurized milk, but the standard of UHT milk is higher.
Packing instructions:
In order to ensure the long-term safety of sterilized milk, it is necessary to use aseptic packaging to package the milk to protect the product from the influence of light and oxygen in the air, so as to effectively inhibit the reproduction of microorganisms in the milk while retaining the original nutritional components of the milk, so that the product can achieve commercial sterility and realize storage and transportation without preservatives and cold chains.
Aseptic packaging is a process, including the selection of packaging materials and aseptic filling process. Some careful consumers may have found that the packaging of long-lasting fresh milk is a "green" material composed of paper, aluminum foil and polyethylene plastic layers.
This material can effectively prevent re-pollution, but also block the invasion of light, oxygen and microorganisms, thus achieving high-quality, fresh, nutritious and delicious effects.
Secondly, the fresh milk that has been sterilized and aseptically packaged by ultra-high temperature (UHT) can be aseptically filled, so that it does not need to be refrigerated during storage and transportation. When the product reaches consumers, its quality and nutritional value are still intact.