1. Various microbes compete with humans for the same sources of food.
Science and Technology in Society – How do science and technology affect the quality of our lives?
7.4 - Technology allows us to improve food production and preservation, thus improving our ability to meet the nutritional needs of growing populations.
Various microbes compete with humans for the same sources of food.

2. C21. Describe how freezing, dehydration, pickling and irradiation prevent food spoilage caused by microbes.

3. Food Production & Preservation
Technology Improves Our Ability to Meet the Nutritional Needs of A Growing Population

4. Food Spoilage Caused by microbes A microbe is a micro- organism
There are 3 main types of microorganisms – fungi, bacteria, and viruses

5. Bacteria Single celled organisms Some are helpful
They help us digest food
Grow in milk to produce yogurt and cheese
What are the dark streaks in bleu cheese?
Right! Mold!

6. Bacteria Bacteria turns apple cider into vinegar
Bacteria changes the smell and taste of food

7. Bacteria
A cut in your hand while you are making potato salad may get staphylococcus bacteria in the salad
Left at room temperature too long, the bacteria produces a toxin that can make you sick

8. Bacteria Salmonella is found in meat, eggs, fish
If not killed during food preparation, it can make you very sick
Attaches to intestine wall & multiples rapidly
Nausea, vomiting, diarrhea and fever

9. Turtles You can also get salmonella bacteria from handling turtles
This is why they cannot be sold in pet stores in CT
Always wash your hands after handling turtles!

10. Food Poisoning
Can be caused by chemicals, heavy metals, fungi, viruses, and most commonly, bacteria
Fever, diarrhea, cramps, death
Poor hygiene, insufficient cooking, contamination of food, eating raw seafood

11. Prevention of Food Spoilage

12. Dehydration Removes water from the food
No water means that fungi, viruses, bacteria cannot grow
Dehydration is a very old process
Raisins, dried fruit of all kinds

13. Pickling Preserves food by using salt and acid to stop bacteria growth
Also an old process
Salt pulls moisture out of food by osmosis or absorption; acid keeps bacteria from growing

14. Canning Food is sealed in glass or “tin” containers and
The temperature in the containers is raised to very high temperatures to kill bacteria
Vegetables & meats sold in CANS in stores
Individuals still “can” vegetables and fruits with pressure cooker

15. Irradiation Process only about 100 years old
Passes food through an irradiation field caused by radioactive materials
Food does not become radioactive
The official symbol on irradiated food.

16. Freezing
Most bacteria can only live at temperatures between 400F (50C) and 1400F (600C)
Freezing keeps food below the lower limit
Most cooking heats food above the upper limit

17. Temperature Extremes
Some bacteria have been found in ice in Antarctica
Some have been found in near-boiling hot springs
BUT both extremes require water
Salmonella will die within 5 days if it does not have water

18. Food Poisoning Prevention Tips #1
Wash hands, surfaces, and utensils before and after food preparation
Why do you think this sign is posted in restaurants & fast food places?

19. PREVENTION Tip #2 Keep raw and uncooked food below 400F (50C)
That is the temperature of the inside of your refrigerator

20. PREVENTION Tip #3 Don’t leave food lying out. Store it properly.
820C = ? F
710C = ? F
650C = ? F

21. PREVENTION Tip #4
Keep cold food cold!
Keep hot food hot!

22. PREVENTION Tip #5 Don’t share eating or drinking utensils.
Don’t take a bite of a friend’s apple
Don’t “double dip”

23. PREVENTION Tip #6
When in doubt, throw it out!