Table 2.
Effect of ethylene (C2H4) treatment on carotenoid composition and C30 apocarotenoid content in the peel of sweet orange (cv. Navel) and mandarin (cv. Clementine) harvested at the onset of natural degreeningFruits were harvested in October with an initial green or light green colour for sweet orange and mandarin, respectively, and exposed to air or 10 µl l–1 ethylene at 20 ºC for 3 d.
| Carotenoid (µg g–1 FW) | Sweet orange | Mandarin | ||||
|---|---|---|---|---|---|---|
| 0 d | 3 d | 0 d | 3 d | |||
| Air | C2H4 | Air | C2H4 | |||
| C40 | ||||||
| Phytoene | 0.61±0.10 | 0.82±0.05 | 3.21±0.52 | 1.04±0.08 | 1.74±0.20 | 5.57±0.85 |
| β-Carotene | 0.41±0.008 | ND | ND | 3.20±0.52 | ND | ND |
| α-Carotene | Tracesa | ND | ND | 2.23±0.26 | ND | ND |
| β-Cryptoxanthin | ND | ND | 0.15±0.04 | 1.52±0.26 | 1.69±0.33 | 2.30±0.29 |
| Zeaxanthin | Traces | 0.54±0.18 | 0.94±0.11 | 0.75±0.09 | 0.46±0.07 | 0.25±0.04 |
| all-E-Violaxanthin | 4.15±0.70 | 3.27±0.61 | 1.57±0.25 | 28.17±0.79 | 17.30±0.81 | 11.70±0.59 |
| 9-Z-Violaxanthin | 5.21±0.56 | 6.21±0.21 | 15.24±2.21 | 27.95±3.98 | 45.99±2.50 | 33.74±3.50 |
| Neoxanthin | 2.25±0.16 | 1.74±0.56 | ND | 6.04±2.36 | 2.41±0.09 | ND |
| Lutein | 6.21±0.62 | 1.21±0.32 | 0.40±0.06 | 21.32±4.17 | ND | ND |
| C30 | ||||||
| β-Apo-8′-carotenal | ND | ND | ND | 0.55±0.13 | ND | ND |
| β-Citraurin | ND | ND | 2.31±0.08 | Traces | 2.79±0.27 | 6.13±0.48 |
The values are means ±SD of at least three measurements.
ND, not detected.
a Traces: carotenoid identified by retention time and spectrum characteristics but their peak area was too low for a reliable quantification.