Determination of best harvest time of German chamomile (Matricaria chamomilla L.) flowers based on solid-phase microextraction-GC-MS analysis data

Abstract

Solid-phase microextraction (SPME) technique is a relatively simple, rapid, inexpensive and solvent-free sampling technique for the determination of volatiles in plant essential oils when compared to conventional sampling techniques like steam distillation solvent extraction (SDSE). Moreover, newer SPME can be automated and does not lead to thermal degradation of chemical components [1,2]. In order to determine best harvest times in terms of quality of chamomile (Matricaria chamomilla L.) grown in Belgium, SPME was applied. On April 15, 2005, 90 day old seedlings were transplanted into the field. At harvest, flowers were divided in two groups on the basis of development stage [3]. Stage I flowers corresponded to initial up to full development of the ligulate flowers, while tubular flowers were closed. Flowers were categorized as stage II when tubular flowers were partially (first circle) up to completely open. After drying, flower heads were analyzed by headspace SPME-GC-MS. Six marker compounds, i.e. (E)-β-farnesene, α-bisabolol oxide A and B, α-bisabolone oxide, (Z)-spiroether and spathulenol were identified and quantities compared statistically for the two different stages of flower development based on their GC peak area. Results indicate that most of the measured traits were not significantly influenced by the stage of development, except for (E)-β-farnesene. The peak area of this compound in stage I was significantly higher than in stage II. These results are in agreement with previous results obtained by SDSE. Therefore, SPME-GC-MS analysis is proposed to be a suitable technique for the differentiation in quality of chamomile flower development stages.