Abstract:
Freezing represent one of the most utilized food preservation methods. Classical freezing techniques have harmful
environmental effects especially because of the refrigerants, which contribute to the ozone layer depletion and to the
increase of the greenhouse effect. Individual quick freezing (IQF) by direct contact with cryogenic agents such as liquid
nitrogen (LN) has a significantly reduced ecological footprint, since nitrogen is a component of atmospheric air, and
therefore it does not pollute. Liquid nitrogen is a by-product of air liquefaction which otherwise should be disposed.
The effectiveness of liquid nitrogen IQF is vastly superior to that obtained by means of classical methods. The paper
aims at highlighting this superiority, reflected mainly by the greatly reduced freezing time. The Lacroix and Castaigne
method is used to determine the total time necessary to reach the prescribed freezing temperature in the thermal center
of the product (in this case, green peas). This way, we prove that individual quick freezing using liquid nitrogen is
characterized by much higher process rates and in addition it benefits from using an environmentally friendly
refrigerant, thus contributing to sustainable development.
