Abstract:The solid phase micro extraction gas-chromatography-mass spectrometry (SPME-GC-MS) was adopted to test the volatile aroma components in raw broccoli samples using automated mass spectral deconvolution and identification system (AMDIS) for data analysis, identified by relative reservation index. The influence microextraction conditions of fiber species and sample preparation methods on the volatile aroma components in raw broccoli samples were investigated. The fiber of 65 μm PDMS/DVB was superior to the fiber of 75 μm CAR/PDMS and 100 μm PDMS on identifying the species and quantities of the volatile aroma components. 22, 25, 22 and 8 volatile compounds were identified in cutting groups, homogenate groups, liquid-nitrogen groups and enzyme-inactivation groups, respectively, which belong to alcohols, sulfides, esters, aldehydes and ketones. The main flavoring compositions in cutting groups were ester compounds, alcohol compounds and then organic sulfides, accounting for 42.11%, 41.22% and 3.53% of the volatile aroma components, respectively. Alcohols (51.58%), organic sulfides (27.21%) and esters (16.19%) were main flavoring substances in homogenate groups, and aldehydes (79.81%), alcohols (3.5%) and sulfides (3.44%) in liquid-nitrogen groups, meanwhile, aldehydes (19.91%), and furfurans (6.96%) in enzyme-inactivation groups, respectively. The results showed the following order of the dimethyl disulfide contents as regard to the flavoring substances from high to low: cutting groups, homogenate groups, liquid-nitrogen groups or enzyme-inactivation groups, with dimethyl trisulfide components identified by the descending order of homogenate groups and liquid-nitrogen groups, which could not be detected in cutting groups and enzyme-inactivation groups (P<0.01). All these results suggested that dimethyl disulfides and dimethyl trisulfides might be produced by enzyme pathways from sulfur-containing amino acids and S-methylthiomethionine. Another dimethyl sulfides, in contrast, might be developed in a nonenzymatic way.