Question

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

Short answer

Microorganisms, such as bacteria, viruses, fungi, and protozoa, can cause undesirable changes in food, leading to spoilage, unpleasant characteristics, and potential health hazards. They can lead to nutrient loss, spoilage through processes like fermentation and decomposition, decay and rot in fruits and vegetables, production of harmful substances like mycotoxins, and foodborne illnesses due to contaminated food. Proper storage and handling of food are crucial to minimize risks and maintain quality, safety, and nutritional value.

Step-by-step solution

Identifying common types of microorganisms

There are several common types of microorganisms, which can be divided into four categories: bacteria, viruses, fungi, and protozoa. Let's briefly mention some examples for each category. Bacteria: Examples include Lactobacillus, Escherichia coli, and Salmonella. Viruses: Examples include Norovirus, Hepatitis A, and Rotavirus. Fungi: Examples include molds such as Penicillium and Aspergillus, and yeasts such as Saccharomyces and Candida. Protozoa: Examples include Giardia, Cryptosporidium, and Entamoeba.

Discussing undesirable changes caused by microorganisms in foods

Microorganisms can cause several undesirable changes in food, which can lead to spoilage, unpleasant characteristics, and even potential health hazards. Some changes these organisms can cause are as follows: 1. Nutrient loss: As microorganisms metabolize and grow in food, they consume essential nutrients, thus depleting the nutritional value of the product. 2. Spoilage: Microorganisms can contribute to food spoilage through processes such as fermentation, oxidation, and decomposition. This can cause off-flavors, off-odors, changes in texture, and the production of gas. 3. Decay and rot: Fungal or bacterial infections in food items like fruits, vegetables, and bread can lead to decay and rot. This process makes the food unsuitable for consumption due to significant changes in taste, texture, and appearance. 4. Production of harmful substances: Certain microorganisms can produce toxic substances in food. For example, some molds produce mycotoxins, which can cause health problems in humans and animals. 5. Foodborne illness: Microorganisms such as bacteria, viruses, and protozoa can cause foodborne illness if they multiply to high levels in contaminated food. Consuming contaminated food may result in symptoms like diarrhea, vomiting, and fever. Examples of bacteria that can cause foodborne illnesses include Salmonella, Listeria, and E. coli. Overall, microorganisms cause undesirable changes in foods that can impact the quality, safety, and nutritional value of the products. It is crucial to properly store and handle food to minimize the risks associated with these organisms.