What is the process of vacuum cooling
The process of vacuum cooling is the rapid refrigeration of a porous product
through moisture removal. Once a product is cut, heat and moisture begin to take
their toll. The product will begin to rot from the inside out. When placed in a
cold room, the heat is removed in a slow continuous process. However with vacuum
cooling the heat is removed very rapidly, allowing for earlier shipping and a
After the product is harvested and packaged, it is placed on pallets for
shipping. The pallets are loaded into a vacuum tight chamber and the process
begins. The equipment drops the pressure inside the vessel by removing air
through vacuum pumps. Once the level of vacuum reaches the "flash point"
moisture and heat are removed from the product in the form of water vapor. The
lower the pressure inside the chamber, the lower the boiling point of water. As
the vacuum goes deeper, more water vapor is removed and the product temperature
is reduced until the desired temperature is achieved.
The water vapor must be removed in order for the process to work efficiently.
The vacuum draws the water vapor past refrigeration coils which condenses the
vapor back into water. These two systems allow the process to achieve desired
product temperature more rapidly than any other post harvest cooling technique.
The rate at which a product can be refrigerated is directly related to the
surface area, density of its tissue and the amount of temperature drop. Typical
cooling times range from 20 to 40 minutes at a temperature drop from 80 to 36
degrees Fahrenheit. The average moisture loss is one-percent for each
eleven-degree Fahrenheit temperature drop.
Since produce is sold by weight, a hydro-vac system can help reduce moisture
loss. This works by spraying clean water over the produce during the vacuum
What it can do for you
Due to the rapid post harvest refrigeration that vacuum cooling allows, shelf
life of the product is extended considerably, thus increasing allowable travel
times and opening new markets. Rapidly cooling products will greatly reduce the
level of microbiological growth during storage. Vacuum cooling has been
documented to have lower levels of microbiological growth than any other cooling
Products suitable for vacuum cooling
Vacuum cooling equipment has been used with good results to refrigerate and/or
dehydrate many products that will dissipate moisture readily, from fresh
vegetables and cut flowers to tobacco and alfalfa. We refrigerate lettuce,
cabbage, mushrooms, flowers and Chinese vegetables on a regular basis. Vacuum
cooling has been used in the produce industry since the 1950's.
years, the vacuum cooling process has been used in many other
Bakery- part-baked bread, bread
rolls and loaves, pastry, pizza, ect.
Fish- cooked tuna,
Cooked and Fresh Meat- beef,
chicken, turkey, meat joints
Frozen and Chilled Ready Meals
Sauces, Soups, Meat Slurries,
To see how your product
will benefit from vacuum cooling click here.