Analysis of volatile compounds from chlorophyll photosensitized linoleic acid by headspace solid-phase microextraction (HS-SPME)

Volatile compounds from linoleic acid with or without added 5 ppm chlorophyll under light and in the dark were studied by headspace-solid phase microextraction (HS-SPME)-gas chromatography (GC)-mass spectrometry (MS). Coefficient of variation (R²) for the total peak areas by HS-SPME was 1.8%. Total volatiles (TI) in linoleic acid without added chlorophyll under light and in the dark were not significantly different for 48 hr at 4°C (p>0.05). TI in linoleic acid with 5 ppm chlorophyll under light at 4°C for 0, 6, 12, 24, and 48 hr increased from 8.9 to 11.6, 21.7, 26.1, and 29.3 (1×10⁴) in electronic counts, respectively. 2-Pentylfuran, an undesirable reversion flavor compound in soybean oil, trans-2-heptenal, and 1-octen-3-ol were formed and increased only in chlorophyll photosensitized samples. Chlorophyll can generate singlet oxygen from triplet oxygen upon the exposure of fluorescent light, which plays important roles in the formation of 2-pentylfuran, trans-2-heptenal, and 1-octen-3-ol in linoleic acid.