Super critical carbon dioxide is used widely now a days in order to preserve fruits and vegetables.

1. Application of supercritical co2
in
fruits and vegetables preservation
Name: Rangina Brahma
Roll no: Fpb15031
B.Tech 4th Sem.
Fruits and Vegetables Processing
Technology

2. What is food preservation?
Refers to number of techniques used to prevent food from spoiling.
Methods such as canning, pickling, drying, freeze drying, smoking and
adding preservatives.

3. Objective
To prevent or slow down the growth of micro-organisms including moulds,
yeasts and bacteria as the growth of these micro-organisms causes spoilage
of food.
To save food for future use at the time of scarcity or drought etc. after
suitable preservation and proper storage.
To increase the shelf life of food as well as its supply.

4. Supercritical

5. What is super-critical carbon dioxide?
Supercritical carbon dioxide (sCO2) is a fluid state of carbon
dioxide where it is held at or above its critical temperature and critical
pressure.
CO2 behaves as a supercritical fluid above its:
critical temperature (31.10 °C)
critical pressure (72.9 atm)
 Expanding to fill its container like a gas but with a density like that of

6. Why supercritical CO2?
Inactivation of microorganisms and enzymes in fruit and vegetable
products
such as juices, purees, and smoothies.
Extraction of bioactive compounds (carotenoids, flavonoids, phenols,
etc.) from fruit and vegetables.
Due to the relatively low temperature used, the production of extracts
without organic solvents is done.
Useful in non- thermal pasteurisation of food.

7. Example
The preservation of carrot juice, for which the shelf life can be
enhanced from two or three days to about three weeks or more.
Pectin methyl esterase and Peroxidase are responsible for cloud
stability disappearance and off-flavour, browning and other changes
occurring during the storage of fresh-like carrot juice, under refrigerated
conditions.
 A micro-bubbled stream of supercritical carbon dioxide at 313 K, 25
MPa inactivated a fraction of PME (above 70%) and of POD (almost
completely) in about one hour.

8. Why only CO2 as the superficial fluid?
Safe, environment friendly
Recyclable
Inexpensive, readily available
Mild conditions
No residue
Zero surface tension

9. CO2 also used in:
Solid form:
In usage for dry ice, usually rice style dry
ice or pellets
Gaseous form:
Such as with gas flush usage for MAP
(Modified Atmosphere Packaging).

10. Why Dry ice?
Acts as a fumigant to kill bugs.
 Less expensive than Nitrogen Sealing.
As means of low temperature storage and transportation of food
products.
Cheaper and far more effective than oxygen absorbers, freezing, or folk
remedies like Diatomaceous earth, bay leaves, etc.
Beside keeping the temperature low , as it sublimes, the gaseous CO2
inhibits growth of psychrotropic microorganisms and prevents spoilage

11. carbon dioxide in map
By reducing the O2-level and increasing the CO2-level:
 Ripening of fruits and vegetables can be
delayed,
Respiration and ethylene production rates can
be reduced,
 Softening can be retarded.
Various compositional changes associated with
ripening can be slowed down.

12. A nanotechnology
Under development for non-thermal pasteurization of food and
perishable beverages by virtue of its effectiveness in micro flora
and enzyme inactivation.
In comparison to competitive technologies, it is particularly
attractive at industrial scale since the liquids can be continuously
processed with recirculating carbon dioxide.

13. Reference
Technology Of Food Preservation & Processing- EIRI BOARD
https://www.ijntr.org/download_data/IJNTR02020042.pdf
www.fao.org