Microorganisms in Food

Food microbiology is the study of the microorganisms that inhibit, create, or contaminate food. This includes the study of microorganisms causing food spoilage; pathogens that may cause disease (especially if food is improperly cooked or stored); microbes used to produce fermented foods such as cheese, yogurt, bread, beer, and wine; and microbes with other useful roles, such as producing probiotics

Microorganisms are of great significance to foods for the following reasons:

• Microorganisms can cause spoilage of foods.
• Microorganisms are used to manufacture a wide variety of food products.
• Microbial diseases can be transmitted by foods.

Foods can be considered as a medium for microbial growth. Considering the vast array of sources, substances, and methods with which food is produced, practically every kind of microbe is a potential contaminant. Given a chance to grow, microbes will produce changes in appearance, flavour, odour, and other qualities of the food. The changes vary according to the type of food degraded but can be summarized by examining the fates of the major nutrients found in food: proteins, carbohydrates, and fats.

Important food items produced in whole or in part by the biochemical activities of microorganisms include pickles, sauerkraut, olives, soy sauce, certain types of sausage, all unprocessed cheeses except cream cheese, and many fermented milk products such as yogurt and acidophilus milk. In each instance a raw food item, such as cucumbers in the case of pickles or milk protein in the case of cheeses, is inoculated with microorganisms known to produce the changes required for a desirable product. The initial food item thus serves as a substrate that is acted upon by microorganisms during the period of incubation. Frequently the manufacturer uses a “starter culture”—a commercial population of microorganisms already known to produce a good product.

Media Contact:

Mary Annabelle
Managing Editor
Microbiology: Current Research
Email: aamcr@alliedacademies.org