Chemical studies on curuba (Passiflora mollissima (Kunth) L. H. Bailey) fruit flavour

The odour-active volatiles of curuba fruit (Passiflora mollissima (Kunth) L. H. Bailey) were isolated by solvent assisted flavour evaporation (SAFE). GC-O and GC–MS analyses identified linalool, hexyl acetate, 1,8-cineole, and butyl acetate as key aroma compounds of this fruit. Other odorants relevant because of their contribution to the overall aroma were: 2-methylpropyl acetate, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate. Sulphur compounds, 3-sulfanylhexyl acetate and methional, were reported here for first time as odour-active volatiles in curuba. By HPLC–ESI-MS analyses of glycosidic mixtures and GC–MS analyses of volatiles released enzymatically with a glucosidase, (Z)-3-hexenyl β-d-glucopyranoside and linalyl β-d-glucopyranoside were identified as aroma precursors in P. mollissima fruit. Thermal treatment of the glycosidic mixture at native pH of fruit gave furanoid cis- and trans-linalool oxides, as well as, α-terpineol, compounds that exhibit flowery odour notes. Biogenic relationships among odour-active volatiles and their glycosidic precursors were also proposed.