Microorganisms in food

Besides the harmful microorganisms, mentioned in the earlier chapters, which can spoil food and therefore play an important role in the food industry, there are also a large number of very useful, so-called beneficial microorganisms that are also extremely important in food processing. Since ancient times, these microorganisms have been used to produce a variety of foods, such as bread, dairy products, fermented vegetables, condiments made from fermented seafood or legumes, vinegar, as well as alcoholic beverages. Fermenting in particular is a method to conserve food while increasing its nutrient value. In the glossary you can find references and descriptions to a large number of traditional fermented products.

Image source: Mohammadhassan Gholami-Shabani et al, Food Microbiology: Application of Microorganisms in Food Industry, 2023

During these biochemical processes certain types of microorganisms change simple sugars like glucose or lactose into alcohol, different acids, or carbon dioxide via a variety of metabolic pathways. For example, Lactobacillus spp. and Streptococcus spp. ferment lactose to lactic acid during the manufacture of dairy products. Acids precipitate protein in milk, which is why fermented products are thicker than milk. The low pH also limits the growth of other potentially harmful microbes, thereby increasing the shelf life of the milk product. Naturally occuring bacteria an on cabbage leaves or on freshly harvested cocoa form the starter culture for their fermentation into sauerkraut and cured cocoa beans respectively. Yeasts (Saccharomyces spp.) decompose sugar to ethanol and carbon dioxide during alcoholic manufacture processes and also provide the carbon dioxide for raising bread dough. As the table above shows, there are many more use-cases for beneficial microorganisms in the food industry, which are described in more detail in the scientific paper linked under the image.