Foods, and Other Products, Formed By Fermentation

A Metabolic Process

Scientist examining a petri dish
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Fermentation is an energy-yielding anaerobic metabolic process in which organisms convert nutrients (typically carbohydrates) into alcohol and acids (such as lactic acid and acetic acid).

Fermentation is perhaps the most ancient biotechnological discovery known to man. Microbrews may be all the rage, but over 10,000 years ago mankind was producing beer, wine, vinegar, and bread using microorganisms, primarily yeast.

Yogurt was produced by way of lactic acid bacteria in milk, and molds were used to produce cheese, to go along with the wine and beer. These processes are still in abundant use today for the production of modern foods. However, the cultures being used today have been purified, and often genetically refined, to maintain the most desirable traits as well as producing the highest quality products.

Foods Formed by Fermentation

Many foods you eat every day are formed through the process of fermentation, including the following.

  • Cheese
  • Foods containing lactic acid, such as sauerkraut
  • Yogurt
  • Bread leavened by yeast

Common Definition of Fermentation

The most common known definition of fermentation is "the conversion of sugar to alcohol (using yeast) under anaerobic conditions, as in the production of beer or wine, vinegar, and cider." Fermentation is among the oldest historical biotechnological processes used by man to produce everyday food products.

 

The Advent of Industrial Fermentation

In 1897 the discovery that enzymes from yeast can convert sugar to alcohol lead to industrial processes for chemicals such as butanol, acetone, and glycerol used in such everyday products as lighters, nail polish remover, and soap. Fermentation processes are still in use today in many modern biotech organizations, often for the production of enzymes to be used in pharmaceutical processes, environmental remediation, and other industrial processes.

Fermentation in Biotechnology

In the world of biotechnology, the term fermentation is used rather loosely to refer to the growth of microorganisms forming on food, under either aerobic or anaerobic conditions.

Fermentation tanks (also called bioreactors) used for industrial fermentation processes are glass, metal or plastic tanks that are equipped with gauges (and settings) that control aeration, stir rate, temperature, pH, and other parameters of interest. Units can be small enough for bench-top applications (5-10 L) or up to 10,000 L in capacity for large-scale industrial applications. Fermentation units such as these are used in the pharmaceutical industry for the growth of specialized pure cultures of bacteria, fungi and yeast, and the production of enzymes and drugs.

A Look at Zymology

The art of studying fermentation is called zymology or zymurgy. Louis Pasteur, the French biologist and chemist renowned for his discovery of pasteurization and the principle of vaccination, was one of the first zymologists. Pasteur referred to fermentation as “the result of life without air."

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