Most beta-glucan testing methods have been designed specifically for grains. Grains are (1-4)-beta-glucans so the use of grain-specific tests is not accurate for mushrooms.

Polysaccharide tests are not valid since they also measure alpha-glucans such as starch.

Starch is a very common polysaccharide that is present in large amounts in staple foods such as potatoes, most grains, corn, and rice. The presence of these starchy materials in a mushroom product will elevate a polysaccharide test and give a false positive for the basidiomycete beta-D-glucans. For this reason it is important to use a test method that is specific to mushroom beta-glucans and will not pick up these alpha-glucans.