- Yeast extract
Yeast extract is the common name for various forms of processed
yeast products that are used as food additives or flavourings. They are often used in the same way thatmonosodium glutamate (MSG) is used, and, like MSG, often contain freeglutamic acid s. The texture ranges from liquid to a light paste. (Herbst p.681) Glutamic acid in yeast extracts are produced from an acid-base fermentation cycle, only found in some yeasts, typically ones bred for use in baking.Autolyzed yeast
Autolyzed yeast or autolyzed yeast extract consists of concentrations of
yeast cells that are allowed to die and break up, so that the yeasts' digestive enzymes break theirprotein s down into simpler compounds.Yeast autolysates are used in
Vegemite (Australia ),Marmite ,Promite , Oxo (New Zealand ,South Africa ,United Kingdom , andRepublic of Ireland ), andCenovis (Switzerland ).Bovril (TheUnited Kingdom andRepublic of Ireland ) switched from beef extract to yeast extract for 2005 and most of 2006, but later switched back. Autolyzed yeast extract is also the primary source ofmonosodium glutamate for the food industry.Fact|date=April 2007Hydrolyzed yeast
Hydrolyzed yeast or hydrolyzed yeast extract is another widely used food additive, used for flavouring purposes.
Manufacture
The general method for making yeast extract for food products such as
Vegemite andMarmite on a commercial scale is to add sodium chloride to a suspension of yeast making the solution hypertonic, which leads to the cells shrivelling up; this triggersautolysis , in which the yeast self-destructs. The dying yeast cells are then heated to complete their breakdown, after which the husks (yeast with thick cell walls which wouldn't do the texture much good) are separated.ee also
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Starch ources
*cite book
last = Herbst
first = Sharon
authorlink = Sharon Herbst
coauthors =
title = Food Lover's Companion
publisher =Barron's Educational Series, Inc.
date =2001
location =Hauppauge, New York
pages =
url =
id =
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