Malt is largely made up of carbohydrates, which are composed of starch, sugars, insoluble cellulose, and soluble hemicellulose. Starch, the most important constituent, accounts for about 60 to 65% of the malt's weight, is composed of amylose, which is reduced to maltose and maltotriose and amylopectins that decompose into glucose. Glucose, a monosaccharide, accounts for about 1 to 2% of the total starch found in a barley kernel. Cellulose constituents do not contribute to fermentable extract or desirable flavors in the malt. Hemicellulose is a constituent of the endosperm cell walls, which consist largely of beta-glucan.
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