Microorganisms in food
1. Introduction
Microorganisms are microscopic organisms that can only be seen under a microscope, as they are less than 1mm in length. They can be found everywhere, in the air, water, soil, in and on the human body, on plants, animals and in discharged body fluids (feces, coughed-up air and nasal mucus, pus, etc.)
Viruses,
bacteria, and protoctists are all microorganisms. Those,
that spoil food and pose a risk to human health are usually called
'germs'. To be able to control contamination of food with these
microorganisms, it is important to understand their specific nature and
how they can contaminate food to a unsafe degree. Only after
understanding the conditions under which they thrive are we able to take
counter-measures to control them and the health risks they cause.
On the other hand many microorganisms in our environment and even in our food are beneficial. They play important roles e.g. in decomposition of organic matter into humus, needed for soil fertility, or populate our gut to keep us healthy. Some are necessary in food processing, like yeasts that raise dough or produce bubbles in beer, or those that culture yoghurt or ferment cabbage into sauerkraut or kimchi, just to mention a few. These beneficial microorganisms are often called 'microbes'.
In this lesson we will take a brief look at both, as it is important for successful and safe food processing to be able to support the 'good ones' and to suppress the 'bad ones'