What’s the difference between ultra-pasteurised and pasteurised milk?
Pasteurisation, a procedure invented by Pasteur, involves heating the milk up to a temperature of 72-75° C and keeping it at this temperature for approximately 15-20 seconds before cooling it. Pasteurised milk has a validity term of 5-15 days if refrigerated accordingly during transport, distribution and market storage. Of course, once unsealed, the milk should be consumed within 3 days, as the milk is a natural fresh dairy and could get altered if it’s not stored at a proper temperature or is contaminated with germs from outside.
Through ultra-pasteurisation the milk is intensely heated for only 2-4 seconds at a temperature of 135 – 150°C. The UHT procedure (Ultra High Temperature) is a continuous process which takes place in a closed system, preventing the product from being contaminated again with germs from the air. The product goes through a rapid succession of heating and cooling stages. The aseptic filling is part of the process which prevents recontamination. The result is a product which can be kept for about six months without refrigeration until being unsealed. Of course, once unsealed, the milk should be consumed within 3 days, as the milk is a natural fresh dairy and could get altered if it’s not stored at a proper temperature or is contaminated with germs from outside.
Isn’t Tetra Pak packaging contributing to environmental pollution with its content of plastic and aluminum?
Tetra Pak packaging have the shape of a tetrahedron (Tetra-Pak system where cardboard is obtained from bleached craft paper, doubled on the inner side with polyethylene) and comply with packaging standards. Producing these packaging from complex materials means several layers of different materials need to be laminated. Each layer of material serves a special function within the product. The Tetra Pak company was the first to adopt the concept of reducing the quantity of material used during fabrication.
- Cardboard from recycled paper is the main ingredient of the complex packaging material, making these hard and resistant.
- Polyethylene makes up 15-20% of the cardboard’s weight and, although being up to 10 microns thick, ensures impermeability against microorganisms and moisture, protecting the packed product and helps binding the materials together.
- Aluminum is used as an up to 9 microns thick foil, representing only 5% of the cardboard weight in case of aseptic packaging when the product requires a higher protection from oxygen and the packed product can be stored without being refrigerated, thus saving energy.
What happens to the nutritional content of processed milk?
The milk collected from farms and brought to the factory passes through various stages within the processing: the homogenisation of fat molecules, fat separation in order to produce standardized milk according to valid norms: skimmed milk (0.1% fat), semi-skimmed milk (1.5% fat) and whole milk (3.5% fat), following the thermal treatment (of pasteurisation or ultra-pasteurisation). By processing the milk, in addition eliminating all germs, the fat quantity is controlled and at the same time all vitamins and nutrients are preserved. The amount of calcium and other minerals for instance is the same for skimmed and whole milk.
After unsealing the UHT milk box, does the milk still maintain its characteristics? At what temperature should it be kept and most of all how many days after opening can it be consumed?
UHT milk maintains its characteristics after unsealing the box. As it is a fresh natural milk, without preservatives, it is recommended that, after unsealing, the milk be kept refrigerated at a temperature of 2-4 degrees Celsius and be consumed within the next 3 days.
If we boil milk from the household (unprocessed and unpackaged) once or twice, doesn’t it become safe for consumption?
Milk loses most of its nutrients during boiling. Moreover, unprocessed milk can contain dangerous bacteria which are not destroyed during boiling.
If you care about the health of your family you should drink packaged milk, which is safest for consumption and best preserves vitamins. Processed and packaged milk underwent sanitary and veterinary controls and was checked several times in the course of the distribution process.
Does UHT milk contain preservatives? Can this innovative technology for long-term preservation of milk (UHT) be real without adding preservatives?
In the absence of bacteria activity and because of packaging pre-sterilisation, the milk becomes less perishable: through ultra-pasteurisation, the validity period of food is prolonged without adding preservatives. The temperatures lie beyond the boiling point (135 – 150° C) and the boiling time is very short (2-4 seconds). This very short stage of heating followed by a sudden cooling destroys bacteria and microorganisms and ensures the preservation of vitamins and nutrients, unlike the normal boiling of raw milk, which doesn’t destroy all germs, destroying instead its vitamins and nutrients.
The numbers on the Tetra Pak box represent the amount of times the milk was reprocessed?
No, not at all, because milk is not reprocessed. That number refers to the number of the roll on which the packaging material is printed; the printing equipment in Tetra Pak factories usually has five rolls and, in some factories, even six rolls. The numbers (1, 2, 3, 4 or 5) are printed in Tetra Pak factories and then the material is delivered to the client. Should this material report a functional damage, it is necessary to identify the roll on which the packaging material was printed, in order to communicate it to Tetra Pak and correct it.
What Is the Tetra Pak Packaging Made of?
Tetra Pak packaging is made only of the cardboard and polyethylene layer (both on the outside and on the inside), in which case it is used for pasteurised milk. For UHT milk another special packaging material is used, which contains aluminum foil in the middle. Thus, the packaging maintains the contents and the milk properties intact for the entire validity period of the product, because it impedes germs and light from penetrating the package (it is a known fact milk changes some of its properties in contact with ambient light).
Is unprocessed milk better than the one available in stores?
Untreated milk can contain a series of pathogens which can seriously damage our health (tuberculosis, diphtheria, polio, typhoid fever and other diseases). Cows can carry organisms which are dangerous for humans, often without developing any special symptom.
Does unprocessed milk have more vitamins than the one available in stores?
Vitamins react to the duration of thermal treatment, not to the temperature. By boiling the milk at home at a temperature of 100 degrees for about 15-20 minutes, most of the vitamins are destroyed. In the factory the thermal treatment lasts for only 2-4 seconds (it is actually a heat shock), which leads to a minimal loss (10%) of milk vitamins (B12, B2, A).
Is UHT milk recommended for children aged 1 and older?
Generally, pediatricians agree to introducing cow’s milk into children’s’ nutrition after the age of 1.
Aluminum is dangerous for our health and causes cancer. The UHT milk packaging also contains aluminum. Doesn’t aluminum affect milk characteristics?
Aluminum doesn’t get into contact with the food product because the inner part of the package is covered with a layer of polyethylene for the food industry.
*Source: Tetra Pak Romania