Identification and aroma impact of norisoprenoids in orange juice

Four norisoprenoids, α-ionone, β-ionone, β-cyclocitral, and β-damascenone, along with their putative carotenoid precursors, were identified in Valencia orange juice using time-intensity GC-O, GC-MS, and photodiode array HPLC. α-Ionone and β-cyclocitral are reported in orange juice for the first time. GC-O aroma peaks were categorized into seven groups with similar sensory qualities: citrus/minty, metallic/mushroom/geranium, roasted/cooked/meaty/spice, fatty/soapy/green, sulfury/solventy/medicine, floral, and sweet fruity. The four norisoprenoids contributed approximately 8% of the total aroma intensity and 78% of the total floral aroma category. The putative carotenoid norisoprenoid precursors, α- and β-carotene, α- and β-cryptoxanthin, and neoxanthin, were identified in the same orange juice using photodiode array HPLC retention times and spectral characteristics.