Gluten. If flour be kneaded under water, the starch is washed out, and a sticky mass remains -
the gluten. When partially dried but still possessing some moisture, it is a tough, translucent, elastic, and tenacious mass, but if thoroughly dried it becomes brittle, and cannot again be made plastic by the addition of water. It is of great importance in bread-making, and owing to its adhesive nature, when yeast is added and carbonic acid gas formed, the bread expands and becomes porous. It is insoluble in water. It contains about 80 per cent. of a fibrin, and about 20 per cent. of ylutin, probably another albuminoid, the formula for which is not yet established. Ordinary flour contains as a rule about 12 per cent. of gluten.