This document discusses the causes and effects of food decay as well as various methods for controlling decay. It notes that bacteria and fungi cause decay by eating and decomposing dead organic materials. Spoiled food should not be eaten as it can cause food poisoning with symptoms like vomiting, stomach pain, and diarrhea. Common methods for controlling decay and preserving food include drying, freezing, vacuum packing, salting or curing, smoking, using preservatives, pickling, canning, and controlling moisture and oxygen levels.

1. SCIENCE 4
Prepared by: Hazel Kate B. Flores, LPT

2. CAUSES AND EFFECTS OF
DECAY

3. • The process of decay is caused by
bacteria and fungi.
• They eat and decompose dead organic
materials that are left exposed in air.
• Left overs may also be acted upon by
bacteria and fungi.

4. SPOILED FOOD
• Spoiled food should not
be eaten anymore.
• They have an awful smell.
• Molds grow on spoiled
breads and fruits.

5. FOOD POISONING
• happens when you eat
spoiled food. It may cause
vomiting, stomach pain,
cramps, or diarrhea.
• Food poisoning may even
cause death

6. CONTROL OF DECAY

7. DRYING
• Is one of the most popular
food preservation
techniques.
• This reduces water activity
to prevent the growth of
molds and bacteria.

8. FREEZING
•Preserves food by
slowing down the
growth of organisms
which causes food to
decay.

9. VACUUM PACKING
•Stores food in an
airtight bag bottle.
•The vacuum
environment
removes oxygen.

10. SALTING OR CURING
•Removes moisture
from the meat.
•Meat is cured with
salt or sugar.

11. SMOKING
• Is used for perishable food
items like fish.
• Shelf life is the amount of
time a material may be stored
without becoming unfit for
consumption.
• Smoking exposes a food item
to smoke from burning plant
materials like wood.

12. PRESERVATIVES
• are food additives that do not
allow the growth of bacteria
or mold.
• Common preservatives
includes nitrates like “salitre,”
which gives tocino its pink
color.

13. PICKLING
• Is a method of preserving
food in an edible liquid that
inhibits or kills bacteria and
other microorganism.

14. CANNING
• Involves sealing food in sterile
cans or jars and boiling the
cans to kill or weaken any
remaining bacteria.

15. ACTIVTY
•Answer Self Check on your book on page 51.

16. ASSIGNMENT:
•Study page 37 to 51 for a Quiz on Monday
(September 21, 2020)