Ultra-high-temperature processing

File:Tetra Pak processing equipment Tetra Lactenso Aseptic.jpg

A Tetra Pak ultra-pasteurization line.

Ultra-high temperature processing (UHT), or ultra-heat treatment, sterilizes food by heating it above 135 °C (275 °F) – the temperature required to kill spores in milk – for 1 to 2 seconds. UHT is most commonly used in milk production, but the process is also used for fruit juices, cream, soy milk, yogurt, wine, soups, honey, and stews. UHT milk was first developed in the 1960s and became generally available for consumption in the 1970s.

The heat used during the UHT process can cause Maillard browning and change the taste and smell of dairy products. An alternative process is HTST pasteurization (high temperature/short time), in which the milk is heated to 72 °C (162 °F) for at least 15 seconds.

UHT milk, if not opened, has a typical unrefrigerated shelf life of six to nine months. HTST pasteurized milk has a shelf life of about two weeks from processing, or about one week from being put on sale.

Nutrition

• Calories

UHT milk contains the same number of calories as pasteurized milk.

• Calcium

UHT and pasteurized milk contains the same amount of calcium.

• Protein

UHT milk's protein structure is different from that of pasteurized milk, which prevents it from separating in cheese making.

• Folate

UHT milk contains 1 μg of folate per 100 g, while pasteurized milk contains 9 μg.

• Vitamin B₁₂, vitamin C and thiamin

Some nutritional loss can occur in UHT milk.

Popularity

UHT milk has seen large success in much of Europe, where across the continent as a whole 7 out of 10 Europeans drink it regularly. In fact, in a hot country such as Spain, UHT milk is preferred due to high costs of refrigerated transportation and "inefficient cool cabinets". UHT is less popular in Northern Europe and Scandinavia, particularly in Denmark, Finland, Norway, Sweden, the United Kingdom and Ireland. It is also less popular in Greece, where fresh pasteurized milk is the most popular type of milk.

UHT milk as a percentage of total consumption

Country	percent
Austria	20.3
Belgium	96.7
Croatia	73
Czech Republic	71.4
Denmark	0.0
Finland	2.4
France	95.5
Brazil	88.1
Germany	66.1
Greece	0.9
Hungary	35.1
Ireland	10.9
Italy	49.8
Netherlands	20.2
Norway	5.3
Poland	48.6
Portugal	92.9
Slovakia	35.5
Spain	95.7
Sweden	5.5
Switzerland	62.8
Turkey	53.1
United Kingdom	8.4

In June 1993, Parmalat introduced its UHT milk to the United States. In the American market, consumers are uneasy about consuming milk that is not delivered under refrigeration, and reluctant to buy it. To combat this, Parmalat is selling its UHT milk in old-fashioned containers, unnecessarily sold from the refrigerator aisle. UHT milk is also used for many dairy products.

UHT milk is sold on American military bases in Puerto Rico and Korea due to limited availability of milk supplies and refrigeration.

UHT milk gained popularity in Puerto Rico as an alternative to pasteurized milk due to environmental factors. For example, power outages after a hurricane can last up to 2 weeks, during which time pasteurized milk would spoil from lack of refrigeration.

Environment

In 2008 the UK government proposed a 90% UHT milk production target by 2020 which they believed would significantly cut the need for refrigeration, and thus benefit the environment by reducing green house emissions. However the milk industry opposed this, and the proposition was abandoned.

In Thailand, there are environmental concerns relating to UHT milk cartons. Tetra Pak (Thai) Ltd. is due to "establish Southeast Asia's first recycling plant for used UHT drink containers".

See also

• Aseptic processing
• Food preservation
• Food storage
• Food packaging
• Food engineering
• Pasteurization

External links

• An article focusing on the negative aspects of UHT milk from the Weston A. Price Foundation
• Milk in a Box. From: Interesting Thing of the Day