What are the common kinds of microorganisms? What undesirable changes do microorganisms cause in foods?

Microorganisms are tiny living organisms, which include bacteria, viruses, fungi, and protozoa. Some common types of microorganisms are: 1. Bacteria: These are single-celled organisms that can be found in various environments, including soil, water, and food. Some common bacteria types include E. coli, Salmonella, and Listeria. 2. Viruses: These are small infectious agents that can only reproduce inside living cells of other organisms. Some common foodborne viruses include norovirus, hepatitis A, and rotavirus. 3. Fungi: These are a diverse group of organisms that include yeasts and molds. Examples of common foodborne fungi are Aspergillus, Candida, and Penicillium. 4. Protozoa: These are single-celled organisms that can cause food- and waterborne illnesses. Some common protozoa include Giardia, Cryptosporidium, and Entamoeba.

Microorganisms can cause undesirable changes in foods by producing various enzymes or toxins, resulting in the following: 1. Food Spoilage: Microorganisms can break down the nutrients in food, leading to off-flavors, odors, or changes in texture. This can make the food unappealing or unsafe to eat. Examples include moldy bread or sour milk. 2. Foodborne Illness: Some microorganisms can produce toxic compounds called toxins, which cause illness when consumed. This can lead to symptoms such as nausea, vomiting, diarrhea, and stomach cramps. Examples of such microorganisms include E. coli, Salmonella, and Listeria. 3. Nutrient Loss: Microorganisms can break down and consume important nutrients in food, reducing its nutritional value. For example, some bacteria can break down vitamins and minerals, making the food less beneficial for human consumption. 4. Reduced Shelf Life: The growth of microorganisms in food can shorten its shelf life, meaning it will spoil more quickly and need to be discarded sooner. This leads to waste and increased costs for consumers and food producers. To prevent these undesirable changes, proper food handling, storage, and sanitation practices should be followed. This can help to minimize the growth of harmful microorganisms and maintain food quality and safety.