UHT milk

UHT milk [ha ː mɪlç ], and long-life milk, is homogenized and preserved UHT milk. It is also referred to as UHT milk, or milk - up (ultra-high temperature and uperisiert ).

UHT milk was introduced in the second half of the 1960s in the market.

Production

For the production of cow's milk is first UHT. For this purpose, it is heated for a few seconds 135-150 ° C and immediately cooled down again to 4-5 ° C. By the action of heat, the milk is sterilized. In addition, proteins are denatured to a low percentage, which can lead ( " cooked flavor " ) and improved digestibility to taste slightly different to the milk. In addition, the viscosity of the milk increased slightly, which makes them seem less watery in the mouth. Subsequently, the milk is homogenised to improve the Aufrahmstabilität. The aim of the homogenization is to reduce the average diameter of the fat droplets and thereby to slow down the creaming.

UHT milk is usually packaged in aluminum-coated cartons (eg "Tetra Pak " ) and hermetically sealed. This prevents the milk is contaminated by novel microorganisms. Filling in brown glass bottles is also practiced.

Benefits

• UHT milk can be stored at room temperature for several months unopened.
• UHT milk is easier to digest.
• UHT milk is cheaper.
• Pathogenic microorganisms are killed.

Disadvantages

• A result of the treatment process is a higher loss of key constituents for humans, for example vitamins, than in the normal pasteurization. This loss can not be compensated by light-tight packaging. In addition, the milk no longer meets then taste the fresh milk.
• The vitamin content decreases during prolonged storage ( within the minimum durability) from further, possibly by up to a further 30 %. The decisive factor is the storage temperature and the quality and care of the heating process ( Difficulty: degassing after steam injection).
• UHT milk is similar to fresh milk in the open state cooled only a few days after preparation. Since the lactic acid bacteria are killed when heated, an incipient spoilage, for example, at a curdling of the milk may not be evident.

Vitamin losses at various heating methods:

In a new method, the UHT milk to be preserved not by heating but by pressure ( 4800-6200 bar). This method of preservation is to reduce the effect on milk flavor.

Nutrients, taste and physical properties

The flavor of pasteurized milk more closely resembles that of fresh cow's milk than in UHT milk. This is due to a partial caramelization of the milk sugar ( lactose ) during the UHT. The nutritional value of the milk depends primarily on their fat content. Full-fat milk contains significant amounts of vitamins A, B and D and calcium. Low fat or non-fat milk does contain the same amounts of protein, calcium, magnesium, phosphorus, potassium, zinc and vitamin B, such as whole fat milk, but the amount of vitamin A and D is halved to non-existent.