Identification of the most odour-active volatiles in fresh, hand-extracted juice of Valencia late oranges by odour dilution techniques

Application of the aroma extract dilution analysis (AEDA) on an extract of the volatiles, isolated by solvent extraction of fresh orange juice followed by sublimation in vacuo at room temperature, resulted in the detection of 42 odour-active compounds with flavour dilution (FD) factors between 4 and 1024. Among the 41 odorants identified, ethyl butanoate (fruity), followed by (Z-hex-3-enal (green) and 3a,4,5,7a-tetrahydro-3,6-dimethyl-2(3H)-benzofuranone (sweet, spicy) showed the highest FD factors. Further key odorants were ethyl 2-methylpropionate, (S)-ethyl 2-methylbutanoate and 4,5-epoxy-(E)-dec-2-enal (FD: 128). Application of the static headspace/olfactometry (SHO) on a sample of the same juice revealed (R)-α-pinene, (R)-limonene, ethyl butanoate, (S)-ethyl 2-methylbutanoate and acetaldehyde as the most odour-active compounds in the headspace above the juice.