Microbes and food 4. Food spoilers
4.1 What is food spoilage?
Like us, microbes need food to stay alive. The foodstuffs that keep us healthy also provide the ideal nutrients for the growth of microbes.
Rotten apple photo
Picture 4.1a A rotten apple
Spoiling food

Microbes are all around us – in the air, the soil, water and our bodies. This means they can soon get into food and, if the conditions are right, multiply rapidly. Unfortunately, when certain microbes grow on food, it soon begins to smell nasty, look slimy, change colour, taste awful or even acquire a furry coating. The food ‘goes off’ – it is spoiled. Even though it may not harm us, it is inedible and must be thrown away. There is also a chance that pathogenic microbes are present along with the spoilers.

Potato blight photo
Picture 4.1b Potato blight is a mould that can spoil a crop in the field. It caused the Irish famines in 1846 and 1848.

Big problem . . .

Around a quarter of the world’s food supply is lost to spoilage by microbes and insects. So what can we do to outwit the microbes and ensure that we consume the food before they do? Over the years man has developed many ways of preserving foods and today’s food technologists have refined the techniques and come up with new ones.

. . . with benefits

We should remember that spoilage is not necessarily a bad thing. It shows us that a food has not been made or kept in the best conditions, alerting us to the possible presence of pathogenic microbes.

Also decomposition returns the chemicals in food back to the environment, to be used again in the life cycles of Earth.

Spoilage microbes

There are three main types of microbes that cause spoilage: