Aseptic packaging technology escorts milk quality

[Chinese Packaging Network News] "A long shelf life of milk is due to the addition of preservatives?" Recently, how to choose milk caused controversy, what is the magic of milk, can be placed under the high moisture, high protein traits more than 90 More than days, "not bad?" In response to this problem, the reporter visited the material scientist Professor Zhang Qinfa. Prof. Zhang used a professional interpretation in simple language to restore the truth of milk preservation for the public: long shelf life of milk, in fact, is based on an already mature technology - sterile packaging materials. technology.

According to experts, the long shelf life of milk on the market can be preserved for up to 6 to 9 months. This type of milk is collectively referred to as room temperature milk. The reason why fresh milk is preserved at room temperature is, in addition to sterilization technology, the more important is the “clothing” technology, which is the packaging technology of milk.

Milk aseptic packaging technology has been in existence for several decades and is now very mature. It is used in the packaging of many liquid foods such as milk and fruit juice. It is nothing new. However, this technology, which was born just after the 40s of the last century, really triggered a "technological revolution." It was therefore hailed by the U.S. Food Technology Research Institute as the most important achievement in food science for 50 years.

The so-called milk aseptic packaging technology, simply put, is to heat raw milk at 137 to 142 degrees Celsius for 2 to 3 seconds, killing bacteria while killing the bacteria spores, while avoiding the destruction of nutrients. Normal-temperature milk is sterilized and filled and sealed with 6 layers of aluminum-plastic composite sterile material.

In this way, because milk is sterile inside, and external bacteria can not get in, at room temperature, its shelf life can reach 6 months, do not add any preservatives. The milk processed in this way is also called room temperature milk or high temperature milk, UHT (Ultra High Temperature Instantaneous Sterilization) milk.

At the same time, the experts are laughing at the problem that consumers are most concerned about, “this processing method will not destroy the effective nutrients of milk at the same time as sterilization.” This is impossible. Over the years, both international and domestic scientific circles have compared the nutritional components of normal-temperature milk and low-temperature milk for many scientific experiments. The conclusion is that there is no significant difference in nutrition between low-temperature milk and room-temperature milk.

In particular, protein and calcium, the main nutrient components in milk, are completely unaffected by the sterilization method. From this perspective, drinking normal-temperature milk and drinking low-temperature milk is no different.