Imagine milk bag viable for 7 weeks without spoiling. This is now a reality. Meet this new method for pasteurized milk shelf life last more.
From the glass bottles that the milkman left at the door of the houses to the UHT system, milk conservation has evolved. The consumption of raw milk possesses a health risk to the consumer, as it may be contaminated with a number of microorganisms.
Pasteurized milk goes through a thermal process at 75ºC for 15 seconds, enough to avoid risk to those who consume it. However it is not sterilized, this means that the more resistant bacteria can multiply and spoil the product in a short time. Its shelf life is short, being closed and refrigerated, 3 to 5 days from the manufacture date.
Professor Bruce Applegate and his colleagues worked with the time-temperature binomial of milk heat treatment.
The process is quite simple, the group found that by increasing and lowering the pasteurization temperature by 10 degrees for less than 1 second, more than 99% of the bacteria remaining after conventional pasteurization is eliminated. Even so, the system is kept at less than 70 ° C, but with these rapid variations.
For this to happen, they use a chamber that spreads small milk drops inside it and thus gets the precision needed for temperature control. The chamber that performs this low-temperature, short-time (LTST) treatment is produced in the United States by Millisecond Technologies.
The group performed sensory tests and the testers did not detect differences in taste, color, aroma or aftertaste between the samples.
According to the professor the method complements pasteurization and makes the milk last another 7 weeks. They have not yet tested raw milk to determine the effectiveness of the technology without prior pasteurization. If successful, the new technique could eliminate the conventional pasteurization process, which consumes more energy and will also reduce losses and food waste in the dairy chain.
This is not the first attempt to make the milk in bags last longer. In Brazil the researcher Adriane Antunes developed a version of the skimmed and lactose-free product at the State University of Campinas (Unicamp), thus making it last up to 50 days.
To reach this result, she used 3 technologies: pasteurization, microfiltration and hydrolysis of lactose, which consists in the use of enzymes to break the milk sugar. The machine, however, is imported from France, which increases the cost of the process.
If you do not give up drinking pasteurized milk, you can now count on a safe and stable product for weeks.