What Is Glucoamylase? The Enzyme That Frees Glucose from Starch

Glucoamylase, also written as gluco-amylase, is an enzyme that releases glucose from starch (1,2). In your body, a similar job is done by maltase-glucoamylase, an enzyme in the lining of your small intestine, which works after amylase has broken the starch into smaller pieces (1,2).

This page is part of our guide to digestive enzymes. Below you will learn what glucoamylase is, how it differs from amylase, which foods contain starch, and where you find gluco-amylase in our products.

written and reviewed by Anouk Martini (registered dietician)

In short

Glucoamylase is an enzyme that releases glucose from starch (1,2).
Your small intestine has a similar enzyme, maltase-glucoamylase, in its lining (1,2).
Amylase cuts starch into smaller pieces first. Glucoamylase works on the ends of those pieces (1).
Gluco-amylase is in our products Starchway, Carbostarch, and Enzymix.

What is glucoamylase?

Starch is a long chain of glucose units. It is found in grain products, potatoes, and pasta. Glucoamylase is an enzyme that removes glucose units from the ends of starch chains and the pieces that remain after amylase has done its work (1).

The two enzymes work in different ways. Amylases break starch into smaller linear pieces, such as maltose chains, and branched pieces called limit dextrins. Maltase-glucoamylase and sucrase-isomaltase then convert those pieces into glucose in the small intestine (1). They are anchored in the lining of the small intestine (2).

What does glucoamylase do in the body?

Your body has its own glucoamylase activity. This is how starch is digested:

In your mouth. Saliva has an enzyme that begins to break down starches (3).
In your small intestine. Pancreatic juice adds more enzymes for carbohydrates, fats, and proteins (3). Amylases cut starch into smaller pieces (1).
At the lining of your small intestine. Maltase-glucoamylase and sucrase-isomaltase turn the pieces into single glucose molecules (1,2).
Absorption. Your blood carries the sugars to your liver, which delivers nutrients to the rest of your body when needed (3).

A gluco-amylase supplement adds the enzyme to your meal. Together with amylase and maltase, gluco-amylase helps break down starches found in foods such as grains, potatoes, and rice.*

Which foods contain starch?

Starch is found in:

Grain products such as bread, oats, and cereal
Pasta and rice
Potatoes
Corn
Processed foods such as cookies and sauces

When might gluco-amylase help?

Some people take gluco-amylase with meals rich in starch, such as pasta, rice, potatoes, or bread. Age, diet, lifestyle, and stress can all affect how well digestion works, and so do the size and type of a meal. A supplement does not replace a balanced diet.

Not sure whether a supplement fits you? Talk to a doctor or dietitian.

Where is gluco-amylase in our products?

Gluco-amylase is in three Intoleran products:

Starchway contains invertase (7500 u, derived from yeast) and gluco-amylase (2500 u / 15 AGU). The enzymes support the digestion of sucrose and starch. Starchway helps to reduce gas and bloating associated with sugar and starchy foods.* It is suitable for vegetarians and vegans and free from gluten and soy.
Carbostarch contains gluco-amylase (2500 u / 15 AGU), invertase (7500 u), alpha galactosidase (1200 u), and lactase (10,000 FCC). It can help to digest lactose, complex carbohydrates, sucrose, and starch.*
Enzymix is a blend of nine digestive enzymes that support the breakdown of carbohydrates, proteins, fats, lactose, and plant fibers.* Its gluco-amylase (50 AGU), amylase, and maltase help break down starches found in foods such as grains, potatoes, and rice.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Not sure which enzyme you need?

Digestive enzymes each have their own job. Answer a few questions in our supplement advisor and see which products fit your situation. You can also ask our dietitians a question.

When should you talk to a doctor or dietitian?

Do your symptoms persist, are you losing weight without trying, or are you cutting out more and more foods? Talk to your doctor or a dietitian. If you have diabetes, talk to your doctor or dietitian before you take a supplement that affects how sugars and starches are broken down. A supplement does not replace medical advice.

Starch digestion involves several enzymes. Amylase goes first, maltase works on maltose, and invertase works on sucrose. See all of our digestive enzymes.

Sources

Mohan S, Eskandari R, Pinto BM. Naturally occurring sulfonium-ion glucosidase inhibitors and their derivatives: a promising class of potential antidiabetic agents. Acc Chem Res. 2014;47(1):211-25. doi:10.1021/ar400132g
Rose DR, Chaudet MM, Jones K. Structural studies of the intestinal α-glucosidases, maltase-glucoamylase and sucrase-isomaltase. J Pediatr Gastroenterol Nutr. 2018;66(Suppl 3):S11-3. doi:10.1097/MPG.0000000000001953
National Institute of Diabetes and Digestive and Kidney Diseases. Your digestive system & how it works [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; last reviewed 2017 Dec. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works