Food Safety
Microbes and spoilage, food preservation methods and food additives.
Before you begin
Food preservation works by making conditions less suitable for microbes; it does not automatically make food sterile.
Learning goals
- Microbes
- Microbial action on food
- Reducing microbial activity
- Lowering pH
- Reducing oxygen
- Reducing water
- Using high temperature
- Using low temperature
- Preservatives
- Nutritional supplements
- Texture and appearance modifiers
Syllabus statements covered
- state what microbes are
- describe the action of microbes on food (e.g. bacteria on milk, mould on bread)
- state that stopping or reducing microbial activity may prevent food spoilage
- describe the following methods of preventing food spoilage and give example(s) for each of them: — lowering pH (pickling)
- describe the following methods of preventing food spoilage and give example(s) for each of them: — reducing oxygen supply (bottling and vacuum packaging)
- describe the following methods of preventing food spoilage and give example(s) for each of them: — reducing water content (freeze-drying, dehydration and use of chemical preservatives)
- describe the following methods of preventing food spoilage and give example(s) for each of them: — using high temperature (sterilisation, pasteurisation and canning)
- describe the following methods of preventing food spoilage and give example(s) for each of them: — using low temperature (freezing)
- explain the use of the following food additives and give examples for each of them: — preservatives (e.g. salt, sugar, sulfur dioxide, vinegar)
- explain the use of the following food additives and give examples for each of them: — nutritional supplements (e.g. minerals, vitamins)
- explain the use of the following food additives and give examples for each of them: — texture and appearance modifiers (e.g. food colourings, starch)
Lessons
Work through them in order.
- Microbes and food spoilageExplain changes caused by bacteria in milk and mould on bread, useful roles of microbes, and the limits of visible safety evidence.
- Food preservation methodsCompare how pH, oxygen, available water and temperature affect microbes, and explain the limits of each preservation method.
- Food additives and their purposesClassify uses of additives as preservatives, nutritional supplements or modifiers, using their stated purposes.
Practise and check
Recommended nextFood Safety topic check