The maple syrup odour of the "candy cap" mushroom, Lactarius fragilis var. rubidus

Headspace volatiles from dried sporocarps of the candy cap mushroom, Lactarius fragilis var. rubidus were analysed using solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). 3-Amino-4,5-dimethyl-2(5H)-furanone (quabalactone III) was identified as the source of the maple syrup odour of the dried mushrooms. The hydrolysis product of quabalactone III, 3-hydroxy-4,5-dimethylfuran-2(5H)-one (sotolon), a compound with an intense maple syrup-like odour, was not observed in mushroom's headspace volatiles.