Micro organisms are used in food industries mainly to
• carry out fermentation;
• produce single cell proteins (SCP); and
• food activities.
Fermentation industries
Micro organisms are used to Carry out fermentation processes in many food industries. The micro organisms act on certain edible substance ms or foods to produce foods
• with properties that help to preserve them;
• having improved flavours and textures; and
• that are easy to digest.
People have been using micro organisms to produce cheese, yoghurt, soy sauce, bread, pickled vegetables and alcoholic beverages for several centuries, long before they knew about the existence of micro organisms.
Single cell proteins (SCP)
Scientists look upper unicellular micro organisms as the promising future suppliers of food proteins (SCP) , for both for farm animals and humans. This is because
• unicellular organisms reproduce rapidly e.g the generation time of yeast is 1 to 2 hours, that of algae is 2 to 6 hours; and
• their cells are rich in proteins (which are better than plant proteins).
Presently , most of our food proteins come from animals and plants. Studies show that in a day,
• a 500kg bullock can produce about 1/2 kg of new proteins;
• 500 kg of soya bean plants can produce about 40kh of new proteins; while
• 500kg of yeast cells can produce approximately 50,000 kg of new proteins.
In addition, yeast cultures takes up a much smaller living space than the soya bean plants and the bullock (includes area of pasture needed to support bullock). Another important factor is that these micro organisms can be grown on substrates such as petroleum by products, agricultural wastes and industrial wastes (e.g. methane, molasses, fruit pulp and paper). This, these micro organisms not only produce food but also get rod of wastes.
Bacteria, yeast and blue algae are the main micro organisms currently used to produce single cell proteins. Most of the SCP are used as cattle feed. More research has to be done to produce palatable single cell proteins which we can eat.
Food additives
Nowadays, many food such as milk powders and cereals are enriched with nutrient supplement s such as vitamins, amino acids and nucleotides. Microbial cultures are used to produce these nutrients in the required high concentrations, e.g. yeast is used to produce B group vitamins.
Microbial cultures are also used to produce many useful enzymes needed in food production.
