Sensory evaluation and gas chromatography-mass spectrometry (GC-MS) analysis of the volatile extracts of pummelo (Citrus maxima) peel

Volatile extracts were prepared from the peel of pummelo by cold pressing (CP), water distillation (WD), simultaneous distillation and extraction (SDE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and super-critical CO2 fluid extraction (SFE). They were analysed by sensory evaluation and gas chromatography-mass spectrometry (GC-MS). The former technique showed that the CP essential oil (CP-EO), MAE and UAE extracts possessed similar odour profiles to the natural pummelo odour, whereas the SDE extract and WD essential oil (WD-EO) presented the fermented/overripe and alcohol/pungent notes, and the SFE extract had a sweet note. Although the GC-MS analyses revealed the six extracts had a certain degree of differences in their compositions, they had similar major volatiles, including limonene (301 476-497 028 mu g/ml), beta-myrcene (86 400-230 400 mu g/ml), beta-pinene (1370-7129 mu g/ml), linalool (1916-4482 mu g/ml) and germacrene D (1165-2327 mu g/ml). Analyses of odour activity values (OAVs) and cluster analysis revealed the fermented/overripe and alcohol/pungent notes of the SDE extract and WD-EO were attributed to nerol, geraniol and linalool oxide. The sweet note of the SFE extract was ascribed to citronellal and limonene oxide. Besides, a lack of limonene, neral and geranial resulted in a light green aroma of the SFE extract. This information might be valuable for further development of aromatically desirable products from citrus fruits. Copyright (C) 2014 John Wiley & Sons, Ltd.