DETECTION AND PARTIAL CHARACTERIZATION OF 8 BETA-DAMASCENONE PRECURSORS IN APPLES (MALUS-DOMESTICA BORKH, CV EMPIRE)

beta-Damascenone, a potent aroma compound in a variety of natural products, is primarily liberated from precursors. Isolation of beta-damascenone precursors from apples Malus domestica Borkh. cv. Empire, using Amberlite XAD-2 adsorption and C-18 flash chromatography columns followed by C-18 HPLC, yielded at least eight separate precursors, of which the most abundant was further purified and characterized. Mass spectra from ion spray tandem MS, GC/MS of TMS sugars, and GC/MS of the enzymatically released aglycon indicated a structure of 9(or 3)-alpha-L-arabinofuranosyl-(1,6)beta-D-glucopyranoside of the acetylenic diol. The sizes of the other precursors were estimated from their retention during size exclusion chromatography (GPC). The presence of two triglycosides, four or more diglycosides, and two or more free aglycons was consistent with the GPC data.