food preservation一問''急''

Freezing:
To store food in a very low temperature to ensure that no bacteria can grow.
(frozen chicken wings: but it takes time to defrost)

Drying:
To prevent water movement inside food so that no bacteria can grow there.
(dried octopus: not easy to keep things dry in a humid city like HK)

Salting:
To add salt to food in order to prevent bacteria from growing.
(salted fish: can only delay the decay process, and the food may include cancer-causing substances)

Canning/Vacuum packing:
To keep things in an oxygen-free environment so that no bacteria can growth inside.
(softdrinks: but even aluminuium cans cannot last forever, and cancer-causing addictives may be included)

For more information you may refer to Wikipedia.


2006-12-06 15:53:00 補充：
cannot last forever means cannot guarantee food quality forever

2006-12-06 16:59:29 補充：
To keep things in an oxygen-free environment so that no bacteria can GROW inside.

Four methods of food preservation:
1) Use salt to preserve - Vegetables; ham; egg
2) Use vinegar to preserve - vegetables;
3) Use vacuum method to preserve - meat;
4) Use oil to preserve - olive; fish;