Used by humans since the Neolithic period (around 10 000 years BC)[1] fermentation helps to preserve perishable foods and to improve their nutritional and organoleptic qualities (in this case, taste, sight, smell, touch).
The scientific rationale of the function of microbes in fermentation started to be built with the discoveries of Louis Pasteur in the second half of the 19th century.
[15] 1881—Emil Christian Hansen isolates Saccharomyces carlsbergensis, a pure yeast culture, which is today widely used in brewing of lager beers.
[16] 1889–1896—Herbert William Conn, Vilhelm Storch and Hermann Weigmann demonstrate that bacteria are responsible for the acidification of milk and of cream.
They contribute to the one or multiple unique properties of a foodstuff especially in regard to taste, flavour, colour, texture, safety, preservation, nutritional value, wholesomeness and/or health benefits.
[36][37] The scientific community is presently trying to deepen understanding of the roles played by microbes in food processing and human health.
[40] Bacterial food cultures are responsible for the aroma, taste and texture of cheeses and fermented milk products such as yogurts, ayran, doogh, skyr or ymer.
[42] Lactic acid bacteria are also used in food supplements as probiotics which help to restore the balance in human intestinal biota.
[43] The most familiar yeast in food production, Saccharomyces cerevisiae, has been used in brewing and baking for thousands of years.
[citation needed] S. cerevisiae feeds on the sugars present in the bread dough and produces the gas carbon dioxide.
[46] Other yeast cultures like Pichia, Torulaspora and Kluyveromyces are naturally present or added to create special flavours in the wine.
[51] Rind-washed cheeses like limburger also ripen inwards, but here, as the name suggests, they are washed with brine and other ingredients such as beer and wine which contain mould.
[53][54][55] In the past, soy sauce has been made by mixing soybeans and other grains with a mould (Aspergillus oryzae or A. sojae) and yeast.
[57] The industrial production of microbial food cultures is carried out after careful selection process and under strictly controlled conditions.
Then, the inoculation material is multiplied and grown either in fermenters (liquid) or on a surface (solid) under defined and monitored conditions.
Some countries even prohibit the back-slopping technique because of the "potential to magnify pathogen loads to very dangerous levels".
[64] A study found that solar-energy-driven production of microbial foods from direct air capture substantially outperforms agricultural cultivation of staple crops in terms of land use.
Land shortage and environmental calamities such as droughts or floods aren't a bottleneck in SCP production.
Commercially available microbial food cultures are sold as preparations, which are formulations, consisting of concentrates of one or more microbial species and/or strains including unavoidable media components carried over from the fermentation and components, which are necessary for their survival, storage, standardisation and to facilitate their application in the food production process.
Safety of microbial food cultures, depending on their characteristics and use, can be based on genus, species or strain levels.
It now covers a wide range of food applications (including dairy, fish, meat, beverages and vinegar) and features a reviewed taxonomy of microorganisms.