Un procédé rapide à basse température permet de prolonger de plusieurs semaines la durée de conservation du lait (en anglais)

Un chauffage et un refroidissement rapides du lait réduisent de manière significative la quantité de bactéries dangereuses présentes, prolongeant ainsi de plusieurs semaines la durée de conservation du lait, selon une étude conduite par l’Université de Purdue. (en anglais)
A rapid heating and cooling of milk significantly reduces the amount of harmful bacteria present, extending by several weeks the shelf life of milk, according to a Purdue University study.

Bruce Applegate, Purdue associate professor in the Department of Food Science, and collaborators from Purdue and the University of Tennessee published their findings in the journal SpringerPlus, where they show that increasing the temperature of milk by 10°C for less than a second eliminates more than 99% of the bacteria left behind after pasteurization.

According to B. Applegate, it’s an add-on to pasteurization, but it can add shelf life of up to five, six or seven weeks to cold milk.

The low-temperature, short-time (LTST) method in the Purdue study sprayed tiny droplets of pasteurized milk, which was inoculated with Lactobacillus and Pseudomonas bacteria, through a heated, pressurized chamber, rapidly raising and lowering their temperatures about 10°C but still below the 70°C threshold needed for pasteurization. The treatment lowered bacterial levels below detection limits, and9* extended shelf life to up to 63 days.

The LTST chamber technology was developed by Millisecond Technologies, a New-York-based company.

Sensory tests compared pasteurized milk with milk that had been pasteurized and run through MST’s process. Panelists did not detect differences in color, aroma, taste or aftertaste between the products.

Phillip Myer, an assistant professor of animal science at the University of Tennessee and a co-author of the paper, said the process uses the heat already necessary for pasteurization to rapidly heat milk droplets. He added that the process significantly reduces the amount of bacteria present, and it doesn’t add any extra energy to the system.

Myer said the promise of the technology is that it could reduce waste and allow milk to reach distant locations where transport times using only pasteurization would mean that milk would have a short shelf life upon arrival.
Applegate said the process could be tested without pasteurization to determine if it could stand alone as a treatment for eliminating harmful bacteria from milk.

The Effect of a novel low temperature-short time (LTST) process to extend the shelf-life of fluid milk
Myer PR, Parker KR, Kanach AT, Zhu T, Morgan MT, Applegate BM