Define the HTST Pasteurization Method?
Rapid, high pasteurization is characterized by a pasteurization time in the order of seconds and temperatures of about 85° to 90°C or more, depending on holding time. Usual temperature/time combinations may be: 88°C for 1 minute; 100°C for 12 seconds; 121°C for 2 seconds. Whereas bacterial destruction is very almost equivalent in low and in high pasteurization processes, the 121°C/2 seconds treatment provides the best quality products in respect of flavour and vitamin retention. Such short holding times, however, need special equipment that is hard to design and usually is more costly than the 63-65°C/30 minutes type of processing equipment.
In flash pasteurization the product is heated up fast to pasteurization temperature, kept at this temperature for the required time, then quickly cooled down to the temperature for filling, which will be carried out in aseptic conditions in sterile receptacles. Taking into account the short time and speedy performance of this operation, flash pasteurization can just be obtained in continuous process by using heat exchangers. Industrial applications of pasteurization process are mostly used for the preservation of fruits and vegetable juices and particularly for tomato juice.