Biology At Work Flashcards
What makes food go off?
Bacteria and Fungi get into the food from the air. They attack the food and make it taste bad.
What do we do to stop from making food taste bad?
Preserve it
How do we preserve?
Kill the microbes in the food and stop them from growing again.
Name the methods of food preservation:[10]
Heating Pasteurization Cooling Drying Chemically Salting Pickling Sugar Smoking Irradiation
Heating food to a high temperature ________ it. It then be canned or bottled.
Sterilizes
Pasteurization kills the bacteria in milk. It was invented by Louis Pasteur. The milk is heated to _______ for 15 seconds, then quickly cooled. This kills most bacteria and does not affect the flavor.
72 Degrees Celsius
Cooling food stops microbes from growing and reproducing but does not ______ them.
Kill
Drying is a way of preserving foods like fruit,vegetables and meat. Microbes cannot live without_______. Some foods like coffee and soups are _______-________. The food is frozen and the ice is drawn off in a vacuum before sealing
Water
Freeze-Dried
Chemicals can kill microbes in food. Many food ________ aft as preservatives.
Additives
Pickling food in vinegar makes it too _____for microbes to live.
Acidic
Adding salt takes the water out of the food by ________.
Osmosis
The sugar in preserved jams also make ______ lose water by osmosis.
Microbes
Which fish are preserved by smoking? And how does this help?
Salmon and Kippers. The smoke kills the microbes in the food.
Irradiation kills bacteria and fungi that cause food ______.
Spoilage
Explain the process of irradiation:[3]
- Food is exposed to gamma radiation
- Kills microbes but does not denature enzymes and the ripening and texture of food is also not affected
- Food cannot be sold for a period of 24 hours after irradiation
