Xylanase is any one of a class of enzymes produced by some microorganisms. These enzymes are involved in breaking down the hemicellulose in the cell walls of plants. Specifically, xylanase hydrolyzes a principal component of hemicellulose called xylan and arabinoxylan. Xylanase is used in the food industry for bread making, the production of corn starch, clarification of fruit juice and wine; animal feeds, and alcoholic fermentation.
Although xylanase is very useful in the food industry, the most important use is in the paper and pulp industry, where xylanase can help replace chlorine in bleaching wood pulp, thus cutting down on dangerous organic halogens, which form toxic dioxins.
Xylanases are produced by organisms such as algae, protozoa, molluscs, crustaceans, insects, bacteria, plant seeds, and many fungi in the genus Aspergillus. Although xylanase for food use is derived from bacteria such as Bacillus subtilis or fungus such as Trichoderma longibrachiatum, those of the Aspergillus are perhaps the most useful, being produced in greater amounts.
Xylanase in Baking
Xylanases are added to dough to help break down polysaccharides in the wheat flours, and thus help stabilize the dough, make it more flexible, and improve gluten strength. Doughs treated with xylanase have increased moisture retention and shelf-life, as well as improved sensory qualities.
Xylanase in Fruit Juice
Xylanase is used in fruit juice processing as part of the maceration process, which breaks down the polysaccharide cell walls to increase the juice extraction yield and to extract more elements such as nutrients and aroma compounds. Xyalanase and other enzymes derived from microorganisms not only help with maceration but by destroying the cell walls, helps clarify the juice and decrease cloudiness. Xylanase can also help clarify wine and beer. The use of xylanase and other enzymes like cellulases and pectinases have greatly increased juice yields, especially in citrus juices.