Inexpensive powdered "S. luteus" fruit bodies are sometimes added to the more expensive "B. edulis" mushroom soup powder, a fraudulent practice that is difficult to detect with microscopy because the tissues are no longer intact. This adulteration can be determined chemically, however, by testing for increased levels of the sugar alcohols arabitol and mannitol. The practice can also be determined with a DNA-based method that is sensitive enough to detect the addition of 1–2% of "S. luteus" to "B. edulis" powder.