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. In milk and milk product processing pdf, HTST pasteurized milk has a shelf life of about two weeks from processing, or about one week from being put on sale. The most commonly applied technique to provide a safe and shelf-stable milk is heat treatment.
In the 1960s APV launched the first commercial steam infusion system under the Palarisator brand name. They made a commercial breakthrough in the 1960s, after technological advances, combining carton assembling and aseptic packaging technologies, followed by international expansion. In aseptic processing, the product and the package are sterilized separately and then combined and sealed in a sterile atmosphere, in contrast to canning, where product and package are first combined and then sterilized. The main goals of the design, both from product quality and from efficiency standpoints, are to maintain the high product temperature for the shortest period possible, and to ensure that the temperature is evenly distributed throughout. Direct systems have an advantage that the product is held at a high temperature for a shorter period of time, thereby reducing the thermal damage for the sensitive products such as milk.
Injection-based, where the high-pressure steam is injected into the liquid. It allows fast heating and cooling, but is only suitable for some products. As the product comes in contact with the hot nozzle, there is a possibility of local overheating. This method achieves near-instantaneous heating and cooling and even distribution of temperature, avoiding local overheating.
However, as higher temperatures are applied, it is necessary to employ higher pressures in order to prevent boiling. For higher efficiency, pressurized water or steam is used as the medium for heating the exchangers themselves, accompanied with a regeneration unit which allows reuse of the medium and energy saving. Cooling rate and the quantity of water removed is determined by the level of vacuum, which must be carefully calibrated. Homogenization is part of the process specific for milk. Homogenization is a mechanical treatment which results in decrease of size and increase of number and total surface area of fat globules in milk number. That, in turn, reduces milk’s tendency to form cream at the surface and on contacts with container, enhances its stability, and makes it more palatable for consumers.
Aseptic packaging refers to technique in which previously sterilised milk is aseptically packaged in a sterile package and hermetically sealed to have prolonged shelf life even under ambient conditions. 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 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. 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. However the milk industry opposed this, and the proposition was abandoned. 100 g, while pasteurized milk contains 9 μg.