VI. Importance of Microorganisms in Foods

Since 1900 A.D., our understanding of importance of microorganisms in food has interested greatly. Their role in food can be either desirable (food bioprocessing) or undesirable (foodborne diseases and food spoilage), which is briefly discussed here.

1. Foodborne Diseases

Many pathogenic microorganisms (bacteria, molds, and viruss) can contaminate food during various stages of their handling between production and consumption. Consumption of these foods can cause foodborne diseases. Foods of animal orogin are associated more with foodborne diseases than foods of plant origin. Mass production of foods, introductionof new technologies in the processing and storage of foods, changes in food consumption patterns, and increase in imports of food from other countries have increased the changes of large outbreaks as well as the introduction of new pathogens. Effective intervention technologies are being developed to ensure the safety of consumers against foodborne diseases. New methods are also being developed to effectively and rapidly identify the pathogens in contaminated foods.

2. Food Spoilage

Except for sterile foods, all foods harbor microorganisms. Food spoilage stems from growth of these microorganisms in food or is due to the action of microbial heat-stable enzymes. New marketing trends, the consumers desire for foods that are not only processed and preserved, extended shelf life, and chances of temperature abuse between production and consumption of foods have greatly increased the chances of food spoilage and, in some instances, with new types of microorganisms. The major concerns are the economics loss and wastage of food. New concepts are being studied to reduce contamination as well as control the growth of spoilage microbes in foods.

3. Food Bioprocessing

Many food-grade microorganisms are used to produce different types of fermented foods using raw materials from animal and plants sources. Consumption of these foods has increased greatly over last 10 t0 15 years and is excepted to increase still more in the future. There have been great changes in the production and availability of these microorganisms starter culture) to meat the large demand. Also, novel and better strain are being developed using genetic engineering techniques.

Microbial enzymes are also being used to produce food and food additives. Genetic recombination techniques are being used to obtain better enzymes and from diverse sources. Many types of additives from microbial sources are being developed and uses in food.

4. Food Biopreservation

Antimicrobial metabolites of desirable microorganisms are being used in foods in place of nonfood preservatives to control pathogens and spoilage microorganisms in food. Economic production of these antimicrobial compounds and their effectiveness in food systems have generated wide interest.

5. Probiotics

Consumption of foods containing live cells of bacteria that have apparent health benefits have generated interest among consumers. The efficiency of these bacteria to produce these benefits is being investigated.