Minzhen SI, Lun LI, ZHANG Chuanyun and ZHANG Deqing
The spectra of volatiles of fresh garlic, Chinese chive and scallion plants were successfully recorded by headspace combined with surface-enhanced Raman scattering using the portable Raman spectrometer. For garlic: high intensity bands are present in 1622, 1397, 1287, 1182, 711, 569, 461 cm-1 and low intensity bands are present in 1017, 979, 918, 307 cm-1. For Chinese chives: the high intensity band is present in 672 cm-1 and low intensity bands are present in 1618, 1396, 1289, 1185, 575, 412, 274 cm-1 . For scallion high intensity bands are present in 699, 1023 cm-1 and low intensity bands are present in 369, 887, 1084, 1314 cm-1 . The main volatiles of fresh garlic, Chinese chive and scallion are diallyl disulfide, allyl methyl sulfide and 1-propanethiol respectively. As the bulk concentration changes, different conformers are absorbed on silver.