But the difference is minor when the milk is served at the same temperature - some people may notice while others do not. There are many health benefits of milk, and they are very similar for both pasteurized and UHT milk. Is UHT milk less nutritious than fresh milk?
The nutritional value of UHT milk and fresh milk are the same when it comes to the main nutrients in milk, such as protein, calcium and Vitamin D. UHT treatment may reduce the level of some heat sensitive nutrients such as vitamin C, but milk is not the main source of these nutrients in the first place.
The storage time also has an influence since some nutrients may degrade with time. Does UHT milk contain calcium? Yes of course. Are the probiotic bacteria killed during the UHT process? Does the absence of probiotic bacteria cause problems in your intestine? Is milk a probiotic source? Neither regular pasteurized milk nor regular UHT milk contain probiotic bacteria. However they can be added in a special form before or after the heating process.
In such case it will and in case of UHT milk with probiotic the product is stored in refrigeration to regulate the status of the probiotics. There are several fermented products with probiotic - like for example yoghurts on the market.
In these products probiotic bacteria are added as an important part of production steps. Does the very high pressure change the protein structure to make it unhealthy? Homogenization is a mechanical treatment where the milk passes through a narrow gap at a high velocity.
This treatment reduces the size of the fat droplets postponing the time for creaming to take place. Homogenization is used to ensure product quality and consistency for all packaged milk, including UHT and pasteurized milk. The pressures used are normally around bar. Most studies investigating the healthy aspects of milk are conducted using homogenized milk, so the homogenising effect is included in the total judgement. How long can I keep UHT milk for?
UHT milk can be kept for months unopened, but the easiest way is to check the shelf life marked on the package. Once opened it must be refrigerated and will last for another few days. UHT milk does not require refrigeration until it has been opened.
Once opened, it is recommended that the milk should be refrigerated and consumed quickly like any other perishable food. Can UHT milk be chilled? Yes, you can if you want to store and drink it chilled, though UHT milk does not require refrigeration for storage until it has been opened. Can UHT milk be frozen? Yes, you can freeze and unfreeze any milk. However, the flavour and the texture of the milk may be affected. Is powdered dried milk made from UHT milk or fresh milk?
Milk powder is made from fresh milk which is concentrated , and thereafter dried. The remaining water then evaporates from the droplets of concentrated milk, leaving a fine powder. However, in many European nations, UHT milk is the norm.
This milk is heated to double the temperature — C — for a mere three seconds. The high heat does its work almost instantly, killing all bacteria and most of the bacterial spores that can stand up to lesser temperatures. Because it's nearly sterile, as long as it is packaged in a container that's aseptic, it will last and last.
No bacteria means no spoilage, at least as long as the package is closed. You can't do just anything to UHT milk, cautions Deeth. It's designed to last at about C, so if it's shipped across the equator on a sweltering ship, or languishes on a dock somewhere in the tropics for a while, some of those remaining spores may come active and cause problems. And peculiar things do happen sometimes to that everlasting milk in its cloistered existence.
The reason that happens can be found in the chemistry that goes on during its treatment and which contribute to some of its odd qualities. With that brief, intense heat comes a change in the milk's proteins. The whey proteins become unravelled, turning into limp strands. The Maillard Reaction, famous for creating the delicious flavours of caramel, perfectly browned toast, and bacon, as well as many other foods, occurs between the milk's proteins and sugars.
An array of enzymes also fall apart, although not, crucially, an enzyme called plasmin, unless the milk is pre-treated to eliminate it. A variety of sulphur compounds are created, giving the newly treated milk an eggy stench that almost entirely dissipates after about a week. If plasmin stays active, it will go around slicing up various proteins, releasing them from whatever they were doing before and allowing them to form attachments to each other.
This seems to be what generates the gel-like agglomerations. The Maillard Reaction is likely behind the fact that UHT milk is noticeably sweeter than its pasteurised cousin. UHT milk is also usually whiter than pasteurised, in fact, Deeth notes. This seems to stem from the way that the unfurled whey proteins and other substances reflect the light. And the sulphur molecules do give it a certain cooked tang to many palates.
Cheeses like these are impossible to make with the heat-treated milk Credit: iStock. While not everyone loves the flavour, UHT milk has more or less conquered the milk market in many places in the world. For instance, it is omnipresent in China, where the appetite for milk has been growing by leaps and bounds.
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