Category: sugar
Aliases: Malt sugar, Maltobiose, D-Maltose, α-Maltose, 4-O-α-D-glucopyranosyl-D-glucose
A reducing disaccharide of two α-D-glucose units joined by an α-1,4-glycosidic bond, released from starch and glycogen by salivary and pancreatic α-amylase. Maltose is not absorbed intact: brush-border maltase-glucoamylase and sucrase-isomaltase hydrolyse it to two molecules of glucose, which enter enterocytes via SGLT1 and exit basolaterally through GLUT2, raising portal glucose and provoking an insulin response comparable to free glucose (high glycemic index). It thus behaves metabolically as a glucose pro-source rather than a distinct sugar, feeding glycolysis, glycogenesis and the pentose-phosphate pathway. Roughly a third as sweet as sucrose, it is a nutritive caloric carbohydrate (~4 kcal/g) common in malt, beer wort and starch syrups; with no specialized intestinal transporter, malabsorption is rare relative to lactose or fructose.
No sweetener E-number (a nutritive sugar, not an additive); roughly 30-50% as sweet as sucrose. GRAS with no numerical ADI, treated as an ordinary caloric carbohydrate. High glycemic index, so it raises blood glucose much like glucose itself — relevant for diabetic glycemic control.