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Yeast: Difference between revisions
→Nutrition
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==Nutrition== | ==Nutrition== | ||
"Nutrition" in this context refers to sources of yeast-assimilable nitrogen (YAN), necessary vitamins, and certain trace minerals. YAN is the amount of nitrogen from the combination of ammonium plus Free Amino Nitrogen (FAN), in the form of amino acids. | "Nutrition" in this context refers to sources of yeast-assimilable nitrogen (YAN), necessary vitamins, and certain trace minerals. YAN is the amount of nitrogen from the combination of ammonium plus Free Amino Nitrogen (FAN), in the form of amino acids. | ||
Wort produced from a high percentage of malt tends to supply necessary vitamins in levels well beyond what is needed for fermentation (including biotin, inositol, and pantothenate). The levels left after fermentation as to the overall nutritional value of beer. Malt also tends to add the required levels of copper, iron, zinc, and magnesium.<ref name=fix>Fix, George. ''Principles of Brewing Science.'' 2nd ed., Brewers Publications, 1999.</ref> | |||
Nitrogen is generally plentiful in wort and typically does not require supplementation for beer production.<ref name="Ferreira"/> The concentration of the amino acids isoleucine, valine, phenylalanine, glycine, alanine, tyrosine, lysine, histidine, arginine and leucine, are considered important, as these are an important part of the complex system regulating the biosynthesis of flavour-active compounds formed by yeast.<ref name="Ferreira"/> However, if supplementation is desired, a mixture of amino acids is more favorable to growth than when ammonium ions are the source of nitrogen.<ref name="Ferreira"/> Phenolic yeast may have a higher nitrogen requirement.<ref name="Ferreira"/> | Nitrogen is generally plentiful in wort and typically does not require supplementation for beer production.<ref name="Ferreira"/> The concentration of the amino acids isoleucine, valine, phenylalanine, glycine, alanine, tyrosine, lysine, histidine, arginine and leucine, are considered important, as these are an important part of the complex system regulating the biosynthesis of flavour-active compounds formed by yeast.<ref name="Ferreira"/> However, if supplementation is desired, a mixture of amino acids is more favorable to growth than when ammonium ions are the source of nitrogen.<ref name="Ferreira"/> Phenolic yeast may have a higher nitrogen requirement.<ref name="Ferreira"/> | ||