2. COOLING
• REFRIGERATION-food is maintained at temperatures
only a few degrees above 0ºc
• FREEZING-the food i store between 0ºc and-18ºc
• DEEP FREEZING-the food is kept between -35ºc and -
150ºc

3. HEATING
• STERILISATION-the food is subjected to temperatures
between 110ºc and 120ºc
• UHT(ULTRA HIGH TEMPERATURE)-the food is
heated to a very high temperature(135ºc)for a few seconds
• PATEURISATION-a temperature os about 72ºc is applied
for 15 seconds,and then the food is rapidly cooled down

4. DRYING
• This process involves eliminating the water in
food to stop or delay decomposition.
• FREEZE-DRYING is a common method:the food
is frozen,and then dried in a vacuum to
eliminate the water by sublimation

5. VACUUM PACKING
• This removes the air(and therefore,the
oxygen)from food,so that aerobic
microorganisms cannot survive and many
enzyme reactions connot take place

6. IRRADIATION
• Certain food products are subjected to
radiation.this destroys the enzymes and the
microorganisms

7. FERMENTATION
• Some food can change because of the action
of specific microorganisms through
fermentation.In some cases this not only
makes the food last longer,it also gives the
food new nutritional qualities

8. SMOKING
(aumado)
• The smoke from burning wood contains
substances that kill microorganisms.Also,the
loss of water that occurs during smoking helps
stop food from deteriorating

9. USE OF PRESERVATIVES
• Large quantities of sugar or salt can help
preserve food by killing microorganisms.Jams
and conserves are examples of foods
preserved with sugar
• Vinegar and spices are also good for
preserving food