Effect of hot air drying on flavor compounds and quality of Capsella bursa- pastoris L.

To analyze the effect of hot air drying( 40,50,60,70,80 and 90 ℃) on the aroma components of wild Capsella bursa- pastoris L.,the combination of head space- solid- phase micro- extraction and gas chromatography( HS- SPME- GC- MS) was used.The basic quality and sensory indicators including the contents of vitamin C and chlorophyll were also analyzed. During hot air drying,3- methyl- butanol,octyl alcohol and phenylethyl alcohol disappeared,and the relative contents of leaf alcohol,trans- 2- hexene- 1- alcohol and 2,6- dimethyl cyclohexanol decreased significantly. Aldehydes such as 3- methy butyl aldehyde,crotonaldehyde,2- methyl n- butyl aldehyde,benzene acetaldehyde,beta ring citral aldehyde increased,hexanal,4- heptene aldehyde,( E,E) 2,4- diallyl aldehyde decreased.The characteristic compound methyl nonyl ketone disappeared,3- amino-2,3- dihydro benzoic acid,N- acetyl glutamate lost largely.3- methyl butyric acid,caproic acid,2- methyl butyric acid and trans- 3- hexene acid newly appeared. The results showed that 60 ℃ drying could keep good quality of Capsella bursa- pastoris L.,maintain the highest retention rate of chlorophyll. Moreover,60 ℃ drying maintained the most types and highest retention of aroma components,especially alcohols and aldehydes. The results provide valuable evidence for exploring the drying technology of Capsella bursa- pastoris L.