Key takeaways
- Alpha-glucans include starch; beta-glucans are in the fungal cell wall.
- Mushrooms contain little starch; grain contains a lot.
- A high alpha-glucan result suggests grain or added starch.
- Ask whether alpha-glucans were measured alongside beta-glucans.
Alpha-glucans rarely get a mention on mushroom labels, but they can tell you a lot about a product. This article explains why.
Alpha versus beta
Both alpha- and beta-glucans are chains of glucose, but linked differently. Beta-glucans are part of the fungal cell wall. Alpha-glucans include starch, the main energy store in grains. See What Are Beta-Glucans?
Mushrooms contain little starch
Fungi store energy mainly as glycogen and other carbohydrates, not starch. So a genuine fruiting body product typically has a low alpha-glucan content.
Grain does
Mycelium grown on grain can be sold with the grain included. Grain is largely starch, so these products can have high alpha-glucan content. See Mycelium on Grain Explained.
What testing reveals
Enzyme-based methods measure total glucans and alpha-glucans, then calculate beta-glucans. The alpha-glucan figure acts as a useful check on starch content. See Beta-Glucan Testing Explained.
How to use this
- If a product quotes beta-glucans, ask whether alpha-glucans were measured too.
- A high alpha-glucan result suggests grain or added starch.
- “Polysaccharides” figures can include starch.