Characterising volatiles in tea (Camellia sinensis). Part I: Comparison of headspace-solid phase microextraction and solvent assisted flavour evaporation

In this work, headspace-solid phase microextraction (HS-SPME) was optimised to study the effect of grinding and brewing on tea volatiles. Grinding resulted in an apparent increase of tea volatiles, while the volatile profiles of tea leaves and infusions were qualitatively similar. Moreover, solvent-assisted flavour evaporation (SAFE) was applied for the analysis of tea volatiles. Its working conditions were systematically investigated by adjusting operating parameters (i.e. water bath temperature (20-35 °C), condenser temperature (20-50 °C) and salt addition (20% NaCl (w/w))). Higher water bath temperature, lower condenser temperature and the use of salt were observed to give better extraction. In conclusion, this study improved the knowledge of SAFE as an efficient sampling technique for complex matrices.