Effect of drying methods on the active compounds of chamomile tea

The quantity of the phenolic compounds influences the quality of the dried chamomile flowers. The objective of this work was to study the effect of drying methods on the active compounds of chamomile tea. Chamomile flowers were dried in the following manners: oven-dried at temperature 50-60°C, dried by air-oven at temperature 50-60°C and solar-dried. The Comparison of the quantity of the active compounds, including the total polyphenols and β-carotenes in chamomile tea was studied. Chamomile tea dried with the air oven at a temperature 50-60°C (moisture content, 5.48%) contained the largest amount of polyphenols, 97.387 mg g^-1 DW. The quantity of polyphenol in oven-dried chamomile tea (moisture content, 5.42%) is 52.178 mg g^-1 DW and that of polyphenol in solar-dried chamomile tea is 69.735 mg 
g^-1 DW. The suitable temperature for drying fresh chamomile is between 50-60°C, to maintain the contents of the total polyphenols and β-carotene. A comparison of the drying methods that were investigated, showed that air-oven drying has a higher drying efficiency than solar-drying and oven-drying.