Action of Certain Alpha Amylases

Abstract

Publisher Summary This chapter discusses two main types of amylases; the dextrinogenic, liquefying or alpha amylases, and the saccharogenic or beta amylases. The former cause rapid fragmentation of starches to reducing dextrins which give no color with iodine (dextrinogenic action) and rapid decrease in the viscosity of starch pastes (liquefying action). The products formed by several dextrinogenic amylases are found to exhibit falling or alpha mutarotation. The saccharogenic amylases are characterized by their ability to split maltose rapidly from starches and glycogens without markedly disrupting the rest of the molecule. The dextrins, which remain after the action of saccharogenic amylases, have relatively high molecular weights, are practically non-reducing and retain the property of giving color with iodine. In those cases which have been examined, the reaction mixtures of saccharogenic amylases have been found to exhibit rising or beta mutarotation, hence the name, “beta amylases.” The dextrinogenic amylases exhibit so-called saccharogenic as well as dextrinogenic activities because they cause the formation of reducing substances and sugars; the saccharogenic amylases cause the formation of residual dextrins as well as maltose.