Conservation is the protection of products, such as foodstuffs and medicine, against decay by, for instance, the use of bacteria and fungi.
Conservation is the protection of products, such as foodstuffs and medicine, against decay by, for instance, the use of bacteria and fungi.
The secret of keeping milk longer
There are various ways to conserve things. Think of airtight packaging, pickling in vinegar or brine, (freeze) drying, or pasteurisation. The last method uses heat to kill microbes to make products such as milk keep longer. The technique was discovered by the 19th-century French biologist Louis Pasteur.
Microbes which conserve
Our food would keep for far less time without techniques and means of conservation. Strange as it may seem, we also use microbes to extend the length of time food stays good, for example in the case of yoghurt. The bacteria in yoghurt turn lactose into lactic acid (fermentation). This creates an acidic environment where other bacteria can (hardly) grow. That is why yoghurt keeps longer than ordinary milk.