Search results
Results from the WOW.Com Content Network
Microbial food cultures are live bacteria, yeasts or moulds used in food production. Microbial food cultures carry out the fermentation process in foodstuffs. 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 effect was described by Louis Pasteur in 1857 in experiments showing that aeration of yeasted broth causes cell growth to increase while the fermentation rate decreases, based on lowered ethanol production. [4] [5]
Top-fermenting yeasts are fermented at higher temperatures than the lager yeast Saccharomyces pastorianus, and the resulting beers have a different flavor from the same beverage fermented with a lager yeast. "Fruity esters" may be formed if the yeast undergoes temperatures near 21 °C (70 °F), or if the fermentation temperature of the beverage ...
Special considerations are required for the specific organisms used in the fermentation, such as the dissolved oxygen level, nutrient levels, and temperature. The rate of fermentation depends on the concentration of microorganisms, cells, cellular components, and enzymes as well as temperature, pH [3] and level of oxygen for aerobic ...
In biochemistry, fermentation theory refers to the historical study of models of natural fermentation processes, especially alcoholic and lactic acid fermentation. Notable contributors to the theory include Justus Von Liebig and Louis Pasteur , the latter of whom developed a purely microbial basis for the fermentation process based on his ...
For other organisms used in biological experiments, such as the budding yeast Saccharomyces cerevisiae, a growth temperature of 30 °C (86 °F) is optimal. More elaborate incubators can also include the ability to lower the temperature (via refrigeration), or the ability to control humidity or CO 2 levels.
However following March 2013, lab notebooks are of limited legal use in the United States, due to a change in the law that grants patents to the first person to file, rather than the first person to invent. [7] The lab notebook is still useful for proving that work was not stolen, but can no longer be used to dispute the patent of an unrelated ...
A laboratory vessel being used for the fermentation of straw Fermentation of sucrose by yeast. The chemical equations below summarize the fermentation of sucrose (C 12 H 22 O 11) into ethanol (C 2 H 5 OH). Alcoholic fermentation converts one mole of glucose into two moles of ethanol and two moles of carbon dioxide, producing two moles of ATP in ...