Maltose

Maltose Function in the Human Body

Maltose is a source of energy; it can provide about 4 Calories per gram,which is about the same as glucose or sucrose.

Maltose Sources

• Maltose is an intermediate product of the starch digestion.
• Free maltose (as a disaccharide) in significant amounts is naturally present in spelt, kamut and sweet potatoes ^[1].
• Syrups high in maltose: high maltose corn syrup (HMCS), barley malt syrup, also called barley malt sugar or dark malt syrup (which is a thick brown syrup), brown rice syrup, corn syrup ^[1].
• Beverages containing maltose: certain beers, ciders, compotes, kombucha rice malt, “malt beverages” (non-alcoholic).
• Processed foods high in maltose: certain ready-to-eat cereals, jelly candies, chocolates, compotes, caramel sauce, confections (especially in China, Taiwan, Hong Kong) ^[1,2].

Chart 1. Foods High in Free Maltose
FOOD	MALTOSE (grams)
Beer, strong ale, 8 vol% alco (12 oz, 355 mL)	22
Barley malt syrup (1 tbsp, 20 g)	12-15
High maltose corn syrup (HMCS) (1 tbsp, 20 g)	4.5-13.5
Sweet potato, baked (1 cup, mashed, 200 g)	13
High maltose corn syrup (HMCS, 65% maltose) (1 tbsp, 20 g)	10
Beer, lager, 4.7 vol% alco (12 oz, 355 mL)	7.5
Brown rice syrup (1 tbsp, 20 g)	7
Ready-to-eat cereals (1/2 cup, dry)	6
Cider, 4.7 vol% alco (12 oz, 355 mL)	2-6
Pears, canned, solids and liquids (1 cup, 265 g)	5
Jelly candies (2 oz, 57 g)	4
Pizza, meat and vegetables (1 slice, 150 g)	3.5
Sundae, caramel (1 piece, 165 g)	3.5
Peaches, canned, solids and liquids (1 cup, 250 g)	3.5
Shake, strawberry (1 cup, 237 mL)	3.5
Bagel, plain (3.5 oz, 100 g)	3
Bread, whole wheat (two slices, 6“x 4“ x ½”, 3.5 oz, 100 g)	3
Grapes (1 cup, 90 g)	3
Light corn syrup (1 tbsp, 20 g)	3
Guava nectar, canned (1 cup, 237 mL)	2
Dark corn syrup (1 tbsp, 20 g)	2
Pancake syrup (1 tbsp, 20 g)	2
Nougat candy (1 oz, 28 g)	2
Beer, alcohol free (12 oz, 355 mL)	1
Steak, breaded (1 piece, 175 g)	1
Honey (1 tbsp, 21 g)	Up to 1

Chart 1 references: USDA.gov ^[1], Fineli.fi ^[2]

Maltose Digestion

In the small intestinal lining, the enzymes maltase and isomaltase break down maltose to two glucose molecules, which are then absorbed. Glucose from maltose is absorbed faster than pure glucose ^[5]. Some maltose can be absorbed as such, without being broken down into glucose ^[6]. Maltose and its digestion product glucose attract water from the intestinal wall (osmotic effect) so they can cause diarrhea if consumed in excess. The laxation threshold for maltose in healthy people is about 120 grams per day ^[7-p.320].

Maltose and Dental Caries

Maltose, including maltose released from the digestion of starch in mouth, can promote dental caries.

Maltose Intolerance

Individuals with a congenital sucrase-isomaltase deficiency may experience bloating and diarrhea after ingesting maltose, sucrose or starch ^[8].

Maltose, Blood Glucose Levels and Diabetes

• Maltose has a high glycemic index (GI = 105) ^[9] and can cause greater blood glucose spikes than sucrose.
• An antidiabetic drug acarbose inhibits the digestion of maltose, which results in slower glucose absorption and lower blood glucose spikes after carbohydrate meals ^[10].

Who can benefit from avoiding/limiting maltose intake?

Individuals with the following conditions can benefit from avoiding maltose:

• Diabetes mellitus
• Celiac disease ^[20]
• Reactive hypoglycemia ^[11]
• Postprandial hypotension ^[12]
• Glucose-galactose malabsorption ^[13]
• GLUT-1 deficiency syndrome ^[14]
• Congenital sucrase-isomaltase deficiency (CSID) ^[8]

Maltose Production

Maltose is produced from corn, barley, tapioca or sago palm starch using the enzyme alpha-amylase of fungal origin ^{[3,4,producers]}.

Maltose and Cooking

• Maltose powder is commercially available as maltose, maltose sugar or malt sugar, which is a white crystalline substance without odor, 50% as sweet as sucrose ^[21]. Chemically, maltose powder is usually in a form of maltose monohydrate (each maltose molecule is connected with one water molecule).
• Maltose monohydrate is very hygroscopic; it readily attracts moisture at 60% relative humidity ^[15-p.86].
• Solubility of maltose monohydrate in water at 68 °F (20 °C) is 108 g/100 mL ^[16].
• Maltose monohydrate melting point is 216.5-266 °F (102.5-130 °C) ^[16,22]. During 30-minutes cooking at 356 °F (180 °C), most of maltose decomposes ^[17-p.267].
• Maltose is a reducing sugar ^[18], so it takes part in the Maillard browning reaction with amino acids.
• Caramelization of maltose starts at 356 °F (180 °C) ^[19].
• Maltose is a fermentable sugar, so it can be used in the production of beer ^[23].