Simple pasteurization 'add-on' gives milk a 63-day shelf life

Depending on how it is treated, delivered, and stored, milk can have a shelf life as low as a couple days and as high as a couple of weeks. A new method for pasteurizing milk, though, has resulted in milk that stays good for more than two months, potentially providing a way for one of the world's dietary staples to stay good for much longer without changing how its tastes, its texture, or its color.

This work was led by the University's Department of Food Science associate professor Bruce Applegate, who worked with a team from both Purdue and the University of Tennessee. According to their work, which was recently published in SpringerPlus, a simple pasteurization "add-on" can greatly extend the shelf life of milk by eliminating nearly all of the bacteria that remains after the traditional pasteurization process is complete.

The add-on process involves quickly heating pasteurized milk by 10 degree Celsius, making sure to keep it below 70C, then cooling it back down. The researchers used a pressurized and heated chamber to do this, spraying the milk through it. All but about 1-percent of the bacteria found after pasteurization remains, and the researchers found the treated milk can last up to 63-days as a result.

This is called the LTST method, which stands for low-temperature short-time, and it was created by Millisecond Technologies. Because the pasteurization process itself requires heat, adding this new element of treatment to it won't increase how much energy is needed to treat milk. Assuming it finds its way into commercial usage, the process will make it possible to deliver milk to more rural and relatively inaccessible regions without it going bad.

SOURCE: Purdue University