Characterization of the Major Aroma-Active Compounds in Peel Oil of an HLB-Tolerant Mandarin Hybrid Using Aroma Extraction Dilution Analysis and Gas Chromatography-Mass Spectrometry/Olfactometry

INTRODUCTION: The main purposes of this study were to identity major peel oil odorants and determine which aroma compounds are primarily responsible for the overall aroma profile of a recently developed Huanglongbing (HLB)-tolerant mandarin hybrid. METHODS: The aroma-active compounds present in the recently developed mandarin hybrid peel oil were extracted by solvent-assisted flavor evaporation (SAFE) and then analyzed by gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and aroma extract dilution analysis (AEDA). RESULTS: Thirty odor-active compounds in the flavor dilution (FD) factor range of 2 to 256 have been identified. On the basis of high FD factors, α-pinene, limonene, β-myrcene, linalool, and β-caryophyllene were characterized as the most essential aroma compounds at a FD factor ≥ 128, followed by γ-terpinene, β-pinene, terpinolene, p-dimethylstyrene, (E)-linalool oxide, decanal, β-cubebene, α-terpineol, and perilla aldehyde at a FD factor ≥ 16. Among all the detected aroma compounds, limonene was the most abundant compound (86.5 ± 2.8%), followed by γ-terpinene (5.3 ± 0.1%), β-myrcene (2.4 ± 0.1%), and α-pinene (1.2 ± 0.0%). CONCLUSIONS: The compounds including α-pinene, limonene, β-myrcene, linalool, and β-caryophyllene were characterized as the most essential aromas. The sensory evaluation results indicated that the major attributes (FD ≥ 2) such as floral, lemon, peel-like, green, mint, and sweet were comparable to that of natural mandarin peel oil. IMPLICATIONS: Based on the human perception, olfactometry and AEDA were used to determine the aroma-active compounds in the peel oil. Human perception also involved in aroma reconstitution to compare the re-engineering solution containing the essential aroma compounds with the natural mandarin oil.