The word ‘cryogenic’ comes from the Greek word ‘kryos’, which means cold and is simply study of materials at low temperature such as 77 K.
It is believed that the first ever successful liquefaction of any cryogenic gas was carried out not earlier than 1877, by a French mining engineer Cailletet who produced a mist of liquid oxygen droplets.
He succeeded in pre-cooling a container filled with oxygen at 300 atm and then expanding the gas by suddenly opening the valve of the container.
Scientist have been experimenting with the use of extreme cold to strengthen metals since mid 1800s, but it was not until the advent of space travel that cryogenic processing really came into own.
NASA engineers analyzed spacecraft that had returned from the cold vacuum of space and discovered that many of metal parts came back stronger than they were before spending time in space.
In the early 1880s, one of the first low-temperature physics laboratories the Cracow University Laboratory in Poland was established by Szygmunt von Wvroblewski and Olszewski.
They obtained liquid oxygen ‘boiling quietly in a test tube in sufficient quality to study properties in April 883. A few days later, they also liquefied nitrogen. Ten years later Olszewski and a British scientist Sir James Dewar liquefied hydrogen.
In 1902 Georges Claude improved the efficiency of air liquefaction by including reciprocating expansion engine.
From the early 1960s food freezing with liquid nitrogen developed very rapidly when it was found that food that is frozen cryogenically had superior quality to the frozen by mechanical freezing.
The method of cryogenic processing materials at sub-zero temperatures was first acknowledged when metal parts that were transported via train have been crammed with dry ice (at -79 ° C) resulting in perceptible increases in wear resistance.
Rapid freezing in liquid nitrogen prevents the formation of the large, long, needle-like crystals present in slow freezing, and less damage occurs to delicate food cells because the rupture of the cell walls during freezing is avoided.
History of cryogenic freezing of food
