Carrot juice

Photo by Copyright, ISAPP 2019.

Fermented foods are defined as “foods or beverages made via controlled microbial growth and enzymatic conversions of major and minor food components.” Through history, fermentation has served as a way to preserve and process foods and change their nutritional profiles—but not least, to give them desirable organoleptic properties.

Fermentation processes are classified by the microorganisms, the primary metabolites these microbes produce, and the type of food undergoing fermentation. These include alcohol and carbon dioxide (produced by yeasts), acetic acid (Acetobacter), lactic acid (lactic acid bacteria, or LAB), propionic acid (Propionibacterium freudenreichii), and ammonia and fatty acids (Bacillus, molds). The food substrates vary as well: meats, fish, milk, vegetables, soy beans and other legumes, cereals, starchy roots, and fruits. Common examples of fermented foods are kimchi, sauerkraut, kombucha, yogurt, miso, and most cheeses and traditional salamis.

Not all fermented foods contain live cultures. Many food products undergo further processing after fermentation: pasteurization, smoking, baking, or filtering. All of these processes kill or remove the live microorganisms. Examples of foods that undergo fermentation but do not contain live microorganisms at the time of consumption are soy sauces, most beers and wines, sourdough bread, and chocolate.

There is a growing acknowledgment that fermented foods have potential nutritional and functional benefits. The literature suggests transforming the original food substrates through fermentation leads to the formation of bioactive or bioavailable end-products. This can increase the concentrations of vitamins or bioactive compounds available to the host, and also may remove or reduce toxins in these foods. While studies are limited, data suggest that consumption of fermented foods may be linked to better health. Some large cohort studies found strong associations between weight maintenance and the consumption of fermented dairy products. Other long-term prospective studies showed reductions in the risk of cardiovascular disease, type 2 diabetes, and overall mortality with frequent yogurt intake. More randomized, controlled trials are needed to confirm and measure the effects of fermented foods—and the live microorganisms some of them contain—on health.

This ISAPP educational video covers fermented foods and how they may affect health.