non-toxic and leave no residue on the product. In packaging uses, carbon dioxide
gas, generated from liquid, is used as an inert medium to prevent flavor loss,
deterioration by oxidation, and growth of bacteria. Carbon dioxide is used for
packaging coffee and in the processing and transporting of fruits, vegetables, and
cereals. Liquid carbon dioxide is used to refrigerate food both prior and during
shipment. It is sometimes used to pre-cool trailers equipped with conventional
refrigeration systems. Trailers can either be filled with dry ice or contain special
boxes that will accumulate CO 2 snow, injected from a liquid supply tank. As said
above, when L-CO 2 is directly injected into trailers, some of the liquid carbon
dioxide also deposits as layers of snow, directly on the food or on surfaces of the
containers. The gradual sublimation during shipment provides additional refrigeration. The modest equipment costs associated with the use of carbon dioxide
chilling and its rapid effect are the main factors behind carbon dioxide’s popularity
in this use. The technology for modified or controlled atmosphere packaging
(MAP/CAP) is progressing with the employment of breathable flexible films in
combination with gas flushing (carbon dioxide, nitrogen, or blends of the two)
targeting the extension of the shelf life of packaged foods. Such progress is quite
important as it reduces or cancels the use of preservatives and even reduces the
formation of waste, while fully meeting the demand of consumers. The use of CO 2
cooling is now extending to other goods such as cooked-baked goods, meat, and
poultry.
A list of food products packaged, shipped, stored using L-CO 2 is: raw red meat
and poultry, sausages, sliced meat, raw fish, smoked fish, cooked fish, prawns, hard
cheese (pieces and slices), soft cheese, yogurt, and now even lasagna and other
pastas (mass derivatives). The temperature of storage ranges from 0 °C to 6 °C,
depending on the nature of the food. CO 2 is used neat or in mixture with dinitrogen
with respect to which offers better and more flexible solutions.
L-CO 2 is also used for helping slicing certain food that is sliced while still
frozen. Sometimes, L-CO 2 is used to cool liquids by direct injection: CO 2 evaporates with time without any modification of the properties of the original liquid.
Another application of CO 2 is in slaughterhouses for stunning pigs instead of
using electrical stunning, causing less animal stress and injuries. Even poultries or
other animals can be treated similarly.
Further, SC-CO 2 is used for the pasteurization of food and beverages and preserving them from microorganisms growth. Similarly, CO 2 is used as non-toxic
fumigant (pesticide or fungicide) in the treatment of cereals when they are shipped
or stored in silos. The use is very simple: gaseous CO 2 is injected in the silos or
container and displaces air by lifting (CO 2 is heavier than air). To be effective at
least 60% CO 2 must be present; therefore, silos do not need to be air tight.
CO 2 blocks the microorganisms’ growth by desiccation. It is safer than usual
fumigants such as CH 3 Br, and microorganisms cannot develop immunity to it.
Additionally, carbon dioxide leaves no residue, and thus does not call for aeration
procedures before cereals are sold to the market. Carbon dioxide is registered with
the EPA as a non-restricted pesticide.
8.3 Uses of CO 2 and Its Quality
127
gas, generated from liquid, is used as an inert medium to prevent flavor loss,
deterioration by oxidation, and growth of bacteria. Carbon dioxide is used for
packaging coffee and in the processing and transporting of fruits, vegetables, and
cereals. Liquid carbon dioxide is used to refrigerate food both prior and during
shipment. It is sometimes used to pre-cool trailers equipped with conventional
refrigeration systems. Trailers can either be filled with dry ice or contain special
boxes that will accumulate CO 2 snow, injected from a liquid supply tank. As said
above, when L-CO 2 is directly injected into trailers, some of the liquid carbon
dioxide also deposits as layers of snow, directly on the food or on surfaces of the
containers. The gradual sublimation during shipment provides additional refrigeration. The modest equipment costs associated with the use of carbon dioxide
chilling and its rapid effect are the main factors behind carbon dioxide’s popularity
in this use. The technology for modified or controlled atmosphere packaging
(MAP/CAP) is progressing with the employment of breathable flexible films in
combination with gas flushing (carbon dioxide, nitrogen, or blends of the two)
targeting the extension of the shelf life of packaged foods. Such progress is quite
important as it reduces or cancels the use of preservatives and even reduces the
formation of waste, while fully meeting the demand of consumers. The use of CO 2
cooling is now extending to other goods such as cooked-baked goods, meat, and
poultry.
A list of food products packaged, shipped, stored using L-CO 2 is: raw red meat
and poultry, sausages, sliced meat, raw fish, smoked fish, cooked fish, prawns, hard
cheese (pieces and slices), soft cheese, yogurt, and now even lasagna and other
pastas (mass derivatives). The temperature of storage ranges from 0 °C to 6 °C,
depending on the nature of the food. CO 2 is used neat or in mixture with dinitrogen
with respect to which offers better and more flexible solutions.
L-CO 2 is also used for helping slicing certain food that is sliced while still
frozen. Sometimes, L-CO 2 is used to cool liquids by direct injection: CO 2 evaporates with time without any modification of the properties of the original liquid.
Another application of CO 2 is in slaughterhouses for stunning pigs instead of
using electrical stunning, causing less animal stress and injuries. Even poultries or
other animals can be treated similarly.
Further, SC-CO 2 is used for the pasteurization of food and beverages and preserving them from microorganisms growth. Similarly, CO 2 is used as non-toxic
fumigant (pesticide or fungicide) in the treatment of cereals when they are shipped
or stored in silos. The use is very simple: gaseous CO 2 is injected in the silos or
container and displaces air by lifting (CO 2 is heavier than air). To be effective at
least 60% CO 2 must be present; therefore, silos do not need to be air tight.
CO 2 blocks the microorganisms’ growth by desiccation. It is safer than usual
fumigants such as CH 3 Br, and microorganisms cannot develop immunity to it.
Additionally, carbon dioxide leaves no residue, and thus does not call for aeration
procedures before cereals are sold to the market. Carbon dioxide is registered with
the EPA as a non-restricted pesticide.
8.3 Uses of CO 2 and Its Quality
127