Effect of Dehydration Temperature on Essential Oil Content of Dried Matricaria chamomilla L.Nobile Flowers

Effect of dehydration temperature on the essential oil content of the dried Matricaria chamomilla L.Nobile flowers was studied.The chemical composition of the dried flowers was determined by means of steam distillation and GC-MS analysis.The experimental results indicated that the essential oil contents in the dried flowers dehydrated at various temperatures ranked as follows:0.134%at 60℃>0.117%at 55℃>0.115%at 50℃>0.102% at 25℃(control)>0.099% at 45℃>0.097% at 40℃.The best fragrance retention was achieved by drying the flowers at 55℃ or 60℃ for 16 h.The best product appearance was resulted from dehydration at 45℃,50℃ or 55℃.At 40℃,the dried flowers were least appealing.The compounds extracted included 8alcohols,which contributed 45.97%-63.01% of the total essential oils,and were higher when the dehydration temperature of 25℃or 50℃ was applied.The 10 alkenes in the extract accounted for 17.46%-33.21% of the essential oils,and were higher in the flowers dried at 55℃ or 60℃.And,the essential oils consisted 16.12%-17.67% of chamazulene,and were higher in the flowers dried at 25℃ or 60℃.