Microorganisms, Spoilage and Food-Poisoning Bacteria
The tiny living things that spoil food and cause food poisoning: bacteria, yeasts and moulds, the conditions they need to grow, high-risk foods, and the five named food-poisoning bacteria.
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The tiny life on food 🦠
Food is full of tiny living things called microorganisms: bacteria, yeasts and moulds. Some are useful and help make foods like bread, cheese and yoghurt. Others spoil food or cause food poisoning. This module looks at what microorganisms need to grow, the signs that food has gone off, and the bacteria that make us ill.
Key words 🔑
Learn these four terms before you study food safety.
Useful or harmful? 🆚
Microorganisms can be helpful in the kitchen or dangerous.
Grade 9 thinking 💡
Learn the five named food-poisoning bacteria precisely: campylobacter, E. coli, salmonella, listeria and staphylococcus aureus. Bacteria grow fastest in the danger zone, between about 5 and 63 degrees Celsius, under current food safety guidance. To stay safe, remove one of the conditions bacteria need, for example chilling food to slow their growth.
Match the growth condition 🔗
- warmth
- moisture
- food
- time
- bacteria multiply fastest in warm conditions
- bacteria need water to grow
- bacteria need nutrients, so high-protein foods are risky
- given enough of it, a few bacteria become millions
Match the microorganism 🧩
- mould in blue cheese
- yeast in bread
- salmonella in raw chicken
- furry mould on old bread
- a useful mould used to make food
- a useful yeast that makes dough rise
- a harmful bacterium that causes food poisoning
- a sign that food has spoiled
What is a high-risk food? ❓
What is a high-risk food?
- A moist food high in protein that bacteria grow on easily and is ready to eat.
- A dry food like biscuits that lasts a long time.
- Any food kept in the freezer.
Conditions for growth ✅
Select the TWO conditions that bacteria need to grow.
- Warmth.
- Moisture.
- Bright light.
- A freezer.
How food becomes unsafe 🪜
An interactive activity.
Summarise food safety 📝
Bacteria, yeasts and moulds are all _____. To grow, bacteria need warmth, moisture, food and _____. Foods that are moist and high in _____ are called high-risk foods. Some microorganisms are useful, such as the _____ that makes bread rise. Harmful bacteria like salmonella can cause food _____.
Count the bacteria 🔢
An interactive activity.
Find the high-risk foods 🖍️
An interactive activity.
Useful, harmful or spoiled? 🧭
An interactive activity.
Keep food safe ✍️
An interactive activity.