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< prev - next > Food processing Food Hygiene and Safety KnO 100260_Making safe food (Printable PDF)
Making Safe Food
Practical Action
Microbes/micro-organisms: very small organisms (animals, plants and fungi) which can only be
seen under a microscope.
Bacteria: the chief microbial danger to food safety comes from poisoning bacteria. They can
multiply very quickly, doubling their numbers every fifteen minutes. This means that one cell can
produce a million others in four to five hours. When conditions do not favour normal growth,
certain bacteria develop "resting stages" called spores. These become active when the conditions
favour growth, for example, water, levels of acidity, oxygen and temperature.
Fungi and moulds: are also micro-organisms. They are most common on foods stored in damp
conditions and may produce toxic by-products.
Yeasts: cause food spoilage but do not cause food poisoning.
They are most commonly found on fruits and in the air.
Viruses: are parasites of living cells of other organisms and cannot multiply outside them.
Similarly, they can survive but cannot multiply in food. They can cause food poisoning.
Condensation: the conversion of a substance from the state of a gas or vapour to a liquid. For
example, steam created by cooking turns into water drops when it touches cooler surfaces such
as windows and walls.
Contamination: making a substance impure or polluted by contact or mixture with another food
or non-food substance.
Enzymes: natural organic substances in foods that can cause both desirable and unpleasant
changes to the flavour, colour and texture of food.
Oxidation: the reaction of oxygen with food which makes the food rancid or taste unpleasant.
Pathogens: poisoning bacteria or viruses.
Stagnant 'Water: water that is without motion or current that does not flow and is still.
Utensils: appliances and implements for use in a kitchen.
Ventilation: the admission of a proper supply of fresh air to a room to allow good circulation.