Maltose - Sources and Absorption

Sources and Absorption

Maltose is a component of malt, a substance which is obtained in the process of grain to soften in water and germinate. It is found in beverages, beer, cereal, pasta, potatoes and in many processed products which have been sweetened.

The production of maltose is based on the hydrolysis of starch, compound by glucose units α(1→4) and α(1→6) linked, meaning that the carbon number 1 is linked by a glycosidic bond to the carbon number 4 or 6 of the other glucose. The 1→4 linked starch part is called amylose and it is a linear polymer while the 1→4 and 1→6 linked part is the amylopectin, a branched chain polymer, being 1→6 the branching point linkages.

This kind of hydrolysis is catalyzed by enzymes called amylases, classified into α-amylases and β-amylases. In the human pancreas the digestion of starch is catalyzed by an α-amylase, as the salivary enzyme. This enzyme can work with amylose and/or amylopectin, but only the interior α(1→4) glucose linkages of the amylopectin molecules as the α-amylase cannot hydrolyze the α(1→6) branching points. The impossibility of hydrolyzing these linkages affects the amylase action: it is weaker near them.

The β-amylases are found in plants, sweet potatoes, soybeans, barley and wheat and are also in bacteria. Theses amylases produce β-maltose and β-limit dextrins, as a result of the enzyme’s impossibility of hydrolyzing α(1→6) branch linkages.

In humans, maltose is broken down by the enzyme maltase so that there are two glucose molecules from which the glucose metabolism obtains energy.