Alpha-glucan

Plain language

Mostly grain starch in a mushroom-supplement context. Not bad for you, but not what you are paying mushroom-supplement prices for. The ratio of alpha to beta on a COA is the cleanest single tell for grain-grown product.

Definition

Alpha-glucans are polysaccharides made of glucose units linked by alpha (1,4 and 1,6) glycosidic bonds. They are the dominant polysaccharide in starch-based grains (oats, rice, sorghum) used as substrates for mushroom mycelium cultivation. They are reported on supplement COAs alongside beta-glucans, and a high alpha-glucan to beta-glucan ratio is the chemistry signature of mycelium-on-grain sold whole.

Related terms

• Beta-glucans 1,3 / 1,6-linked polysaccharides from fungal cell walls. The fraction most mushroom-supplement claims rest on.
• Polysaccharide A long carbohydrate chain. Includes both beta-glucans (often active) and alpha-glucans (often grain starch).
• Mycelium The thread-like vegetative network of a fungus, growing through soil, wood, or grain substrate.
• Fruiting body The mushroom-shaped structure that grows above ground. Where the species-specific actives concentrate in most medicinal mushrooms.

References

• Kozarski et al. (2015) - Antioxidants in mushroom extracts: chemistry, processing, and health benefits