Effect of drying temperature on key odourants in kaffir lime (Citrus hystrix D.C., Rutaceae) leaves

摘要

Volatile compounds of fresh and dried kaffir lime leaves were analysed by gas chromatography-mass spectrometry (GC-MS). Fifty-four volatile compounds were identified in fresh kaffir lime leaf with citro-nellal being the most abundant, followed by L-linalool, hexanal, sabinene and β-citronellol. Aroma active compounds were determined by gas chromatography-olfactory (GC-O). Thirty-seven aroma active compounds were reported along with their odour descriptions and Log_3 FD. On the basis of high values of their Log_3 FD and odour characteristics together with odour activity value (OAV), the concentrations of selected eleven key odourants were compared between fresh and dried samples. Three drying temperatures at 50, 60 and 70 ℃ for 6 h were applied for hot air-drying. The concentrations of most compounds in 50 ℃ dried samples were not much different from those in fresh samples. Drying at 60 and 70 ℃ brought substantial losses of some key odourants, However, concentrations of citronellal and L-linalool, as key aroma compounds of kaffir lime leaves, in 60 and 70 ℃ dried kaffir lime leaves were not significantly different.