2.5 food spoilage

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Start task 'food spoilage'

learning objective

• You can describe ways to prevent food spoilage.

1. Copy the learning objectives (p 125) to your zuidschrift.

2. Can you think of ways to prevent your food from going bad?

     Write down on paper (without checking your book)!

     Crumple your paper into a ball.

3. Check if you have any questions about the homework.

Lesson Pan

1. Start task                5

2. Theory + notes    10

3. Assignments        20

4. End                           5

learning objective

• You can describe ways to prevent food spoilage.

Today's lesson

• Food poisoining
• Preserving food
• Additives

Meyra en Miray are twins. The amount of energy they need is not the same.
What is the most logical reason for this difference?

1. Their sex is different
2. Their body length is different
3. Their age is different
4. Their physical activity is different

Food conservation

What causes your food to spoil?

Micro organisms (molds and bacteria)

The decomposers break down natural waste (chapter 6). 

They secrete toxins (which are harmfull to humans)

Food poisoning

Food spoilage (voedselbederf) = when unwanted fungi or bacteria grow on your food. 

Food poisoning (voedselvergiftiging) = When you fall ill by toxic substances in your food. 

Food spoilage

Bacteria and fungi eat our food = food spoilage

They need:

• Food
• Moisture
• Right temperature
• Right environment

Preserving food is done by changing these things. making it impossible/hard to live on the food for bacteria/fungi

How do you prevent food spoilage?

Preserving (conserveren)= keeping food fresh for a longer period of time

1. Heating 
2. Cooling and freezing 
3. Adding substances (stoffen toevoegen)
4. Vacuüm or special gas packaging
5. Drying

Heating

Sterilize (steriliseren) = Heat at least to 100°C for a while. 

E.g. long-life milk and jam.

Pasteurize (pasteuriseren) = Heat at a lower temperature of around 60°C. Not all micro-organisms die, but the taste of the food does not change very much either. E.g. milk, yoghurt and custard.

What?	Read: bs5 p. 125-127 Make: 1, (2, 3), 4-9 (10) (p. 128-132) (choose: 2+3 or 10)
How?	In your book/ zuidschrift. Whispering collaboration with your neighbour.
Help?	Raise your hand, but ask your neighbour first.
Time?	20 minutes
Finished?	Check your answers (using google classroom).
Outcome?	You have finished your homework! Well done!

processing knowledge 

exit ticket

Fill in the exit ticket (slip) and hand it in when leaving the classroom.

HW: Read: bs5 p. 125-127

Make: 1, (2, 3), 4-9 (10) (p. 128-132) 

(choose: 2+3 or 10)