1. E XTENDING THE SHELF L IFE Commercially produced food has a shelf life. This is the amount of time it is save to eat or in its best condition. When crisps or biscuits pass their sell by dates they are not unsafe to eat but may not be in the best condition overall. A variety of methods are used to try to make the food last as long as possible. Some methods may alter the nutritional value while others mat affect the sensory qualities.

2. M ODIFIED A TMOSPHERIC P ACKAGING MAP This is when the food is sealed in a packet. Then the air is replaced by another gas, which prevents bacterial growth.MAP is used for bacon, smoked fish and fruit and vegetables carried by aeroplane.

3. V ACUUM PACKING This is when the air is removed from a sealed packet. This helps the food to keep its flavour like coffee.

4. I RRADIATION Irradiation has to be declared on the label. It delays fruit and vegetables ripening.

5. A DDITIVES These are chemicals that are added to food.

6. A PPLYING HEAT Micro-organisms are destroyed by high temperatures.

7. D EHYDRATION Removing the moisture from food stops any micro- organisms surviving.

8. R EDUCING THE TEMPERATURE Low temperature slows down the growth of bacteria.