What Are Foods 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) to alcohols and acids (lactic acid and acetic acid).

Fermentation is perhaps the most ancient biotechnological discovery. Over 10,000 years ago mankind was producing wine, beer, vinegar and bread using microorganisms, primarily yeast. Yogurt was produced by lactic acid bacteria in milk, and molds were used to produce cheese.

These processes are still in use today for the production of modern foods. However, the cultures that are used have been purified and often genetically refined to maintain the most desirable traits and highest quality of products.

Foods Formed by Fermentation

Many foods you eat every day are formed through the fermentation process. Examples are:

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

Common Definition of Fermentation

The most commonly known definition for fermentation is the conversion of sugar to alcohol, using yeast, under anaerobic conditions, as in the production of beer or wine, vinegars and cider. Fermentation is among the oldest of historical biotechnological processes that people have been using for thousands of years.

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.

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

However, in biotechnology, the term is used more loosely to refer to growth of microorganisms on food, under either aerobic or anaerobic conditions.

Fermentation tanks, also called bioreactors, used for industrial fermentation processes are glass, metal or plastic tanks, equipped with gages and settings to 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.

What is Zymology?

The art of studying fermentation is called zymology or zymurgy. Louis Pasteur was one of the first zymologists and referred to fermentation as “the result of life without air."

An example would be the fermentation of sugar to wine was done using yeast grown in a bioreactor.

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