Comparative analysis of pomelo volatiles using headspace-solid phase micro-extraction and solvent assisted flavour evaporation

In this work, headspace solid-phase microextraction (HS-SPME) was applied for a comparative study of the volatile profiles of flower, leaf, peel and juice from Malaysia pomelo. Different volatile profiles were observed in these different plant parts based on the analytical results obtained from HS-SPME analysed by gas chromatography-mass spectrometry coupled with a flame ionisation detector (GC-MS/FID). Pomelo peel contained the greatest abundance of volatiles, followed by the leaf, flower and juice. Moreover, the temperature parameters for solvent assisted flavour evaporation (SAFE) were systematically optimised using pomelo juice. The optimised water bath temperature was 20 ± 0.5 °C and condenser temperature was 20 ± 0.1 °C. In general, separation of pomelos by country was observed by principal component analysis (PCA). From the PCA loadings plot, compounds such as citronellol and α-terpineol were identified as contributors to separation in HS-SPME peel and juice respectively, while nootkatone was identified in SAFE extracts. Finally, the sugar and organic acid content of the pomelos were measured by high performance liquid chromatography (HPLC).