Fermentation in food processing
In food processing, fermentation is the conversion of carbohydrates to alcohol or organic acids using microorganisms—yeasts or bacteria—under anaerobic (oxygen-free) conditions. Fermentation usually implies that the action of microorganisms is desired. The science of fermentation is known as zymology or zymurgy.
The term "fermentation" sometimes refers specifically to the chemical conversion of
Other widely consumed fermented foods include vinegar, olives, and cheese. More localised foods prepared by fermentation may also be based on beans, grain, vegetables, fruit, honey, dairy products, and fish.
History and prehistory
Brewing and winemaking
Natural fermentation predates human history. Since ancient times, humans have exploited the fermentation process. The earliest archaeological evidence of fermentation is 13,000-year-old residues of a beer, with the consistency of gruel, found in a cave near
Discovery of the role of yeast
The French chemist Louis Pasteur founded zymology, when in 1856 he connected yeast to fermentation.[8] When studying the fermentation of sugar to alcohol by yeast, Pasteur concluded that the fermentation was catalyzed by a vital force, called "ferments", within the yeast cells. The "ferments" were thought to function only within living organisms. Pasteur wrote that "Alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells."[9]
"Cell-free fermentation"
Nevertheless, it was known that yeast extracts can ferment sugar even in the absence of living yeast cells. While studying this process in 1897, the German chemist and zymologist Eduard Buchner of Humboldt University of Berlin, Germany, found that sugar was fermented even when there were no living yeast cells in the mixture,[10] by an enzyme complex secreted by yeast that he termed zymase.[11] In 1907 he received the Nobel Prize in Chemistry for his research and discovery of "cell-free fermentation".
One year earlier, in 1906, ethanol fermentation studies led to the early discovery of oxidized nicotinamide adenine dinucleotide (NAD+).[12][verification needed]
Uses
Food fermentation is the conversion of sugars and other carbohydrates into alcohol or preservative organic acids and carbon dioxide. All three products have found human uses. The production of alcohol is made use of when fruit juices are converted to wine, when grains are made into beer, and when foods rich in starch, such as potatoes, are fermented and then distilled to make spirits such as gin and vodka. The production of carbon dioxide is used to leaven bread. The production of organic acids is exploited to preserve and flavor vegetables and dairy products.[13]
Food fermentation serves five main purposes: to enrich the diet through development of a diversity of flavors, aromas, and textures in food substrates; to preserve substantial amounts of food through
Fermented foods by region
- Worldwide: alcohol (beer, wine), vinegar, olives, yogurt, bread, cheese
- Asia
- East and Southeast Asia:
- Central Asia: shubat, qatiq(yogurt)
- South Asia:
- Africa:
- Americas: chicha, chocolate, vanilla, hot sauce, tibicos, pulque, muktuk, kiviak , parakari
- Middle East: torshi, boza
- Europe: żur.
- Oceania: poi, kānga pirau
Fermented foods by type
Beans
, thua naoGrain
Vegetables
Fruit
Honey
Dairy
Some kinds of
Fish
Meat
Tea
Risks
Alaska has witnessed a steady increase of cases of botulism since 1985.[16] It has more cases of botulism than any other state in the United States of America. This is caused by the traditional Alaska Native practice of allowing animal products such as whole fish, fish heads, walrus, sea lion, and whale flippers, beaver tails, seal oil, and birds, to ferment for an extended period of time before being consumed. The risk is exacerbated when a plastic container is used for this purpose instead of the old-fashioned, traditional method, a grass-lined hole, as the Clostridium botulinum bacteria thrive in the anaerobic conditions created by the air-tight enclosure in plastic.[16]
The World Health Organization has classified pickled foods as possibly carcinogenic, based on epidemiological studies.[17] Other research found that fermented food contains a carcinogenic by-product, ethyl carbamate (urethane).[18] "A 2009 review of the existing studies conducted across Asia concluded that regularly eating pickled vegetables roughly doubles a person's risk for esophageal squamous cell carcinoma."[19]
See also
- Bletting – Process of softening that certain fleshy fruits undergo, beyond ripening
- Brining
- Corn smut – Fungal plant disease on maize and teosinte
- Curing (food preservation)
- Fermentation in winemaking – Wine making process
- Fermentation lock – Device used in beer brewing and wine making
- Food microbiology – Study of the microorganisms that inhibit, create, or contaminate food
- Industrial fermentation – Biochemical process applied in industrial production
- Industrial microbiology – branch of biotechnology
- Lactic acid bacteria – Order of bacteria
- Lactic acid fermentation – Series of interconnected biochemical reactions
- Pickling
- Symbiotic fermentation
- Yeast in winemaking – Yeasts used for alcoholic fermentation of wine
References
- ^ "'World's oldest brewery' found in cave in Israel, say researchers". British Broadcasting Corporation. 15 September 2018. Archived from the original on 8 August 2019. Retrieved 15 September 2018.
- PMID 15590771.
- ^ "8,000-year-old wine unearthed in Georgia". The Independent. 2003-12-28. Archived from the original on 2019-10-09. Retrieved 2007-01-28.
- ^ "Now on display ... world's oldest known wine jar". Archived from the original on 2012-08-26. Retrieved 2007-01-28.
- ^ a b "Fermented fruits and vegetables. A global perspective". FAO Agricultural Services Bulletins - 134. Archived from the original on January 19, 2007. Retrieved 2007-01-28.
- S2CID 7914033. 15008419. Archived from the original(PDF) on December 9, 2006. Retrieved 2007-01-28.
- ^ Dirar, H. (1993). The Indigenous Fermented Foods of the Sudan: A Study in African Food and Nutrition. CAB International.
- ^ "Fermentation" (PDF). Archived from the original (PDF) on 2012-05-30.
- PMID 8595136.
- ^ "Nobel Laureate Biography of Eduard Buchner". Archived from the original on 2016-06-29. Retrieved 2009-08-26.
- ^ "The Nobel Prize in Chemistry 1929". Archived from the original on 2006-08-27. Retrieved 2007-01-28.
- .
- ISBN 978-0-8247-5122-7. Archivedfrom the original on 2023-03-17. Retrieved 2016-10-22.
- ISBN 9781466565302.
- ^ Steinkraus, K.H., ed. (1995). Handbook of Indigenous Fermented Foods. Marcel Dekker.
- ^ a b "Why does Alaska have more botulism". Centers for Disease Control and Prevention (U.S. federal agency). Archived from the original on 7 August 2006. Retrieved 18 July 2011.
- ^ "Agents Classified by the IARC Monographs, Volumes 1–105" (PDF). International Agency for Research on Cancer (United Nations World Health Organization agency). Archived (PDF) from the original on 24 December 2017. Retrieved 10 October 2012.
- ^ "New Link Between Wine, Fermented Food And Cancer". ScienceDaily. Archived from the original on 11 March 2007. Retrieved 10 October 2012.
- ^ "The WHO Says Cellphones—and Pickles—May Cause Cancer". Slate. June 2011. Archived from the original on 29 September 2011. Retrieved 10 October 2012.