Optical purity of (R)-(−)-1-octen-3-ol in the aroma of various species of edible mushrooms

The characteristic enantiomeric ratio of 1-octen-3-ol in various species of edible mushrooms was the subject of the investigation. The microdistillation–extraction apparatus of Likens–Nickerson was used for aroma isolation. The volatiles were separated on the usual GC capillary column and on the chiral GC column connected to an HP-6890 gas chromatograph. The following species of cultivated mushrooms were analysed: Agaricus bisporus, Pleurotus ostreatus, Hericium erinaceum, Pholiota nameco and Lentinus edodes, and wild growing: Boletus edulis, Xerocomus badius and Macrolepiota procera. Despite significant differences in the concentrations of 1-octen-3-ol, the optical purity of (R)-(−)-1-octen-3-ol in all the species was very high, the highest in A. bisporus (over 98.5%), the lowest in X. badius (over 82.1%). Several mushroom-like flavouring substances and food products of mushroom-like aroma were also tested. In all of them the racemic ratio of 1-octen-3-ol was determined; this suggests that the origin of the flavours was not natural.