Impacts of different brewing conditions on pyrazine and bioactive contents of Turkish coffee

Abstract

Turkish-style brewed coffee, i.e., ground coffee boiled in special pots, is one of the most consumed traditional beverages in Turkey given its unique and delicate flavor. In the current study, the effects of brewing in different pots (automatic coffee machine (ACM), stainless steel pot (SSP), and copper pot in hot sand (CPS) on the pyrazines, total phenolic content, and antioxidant activity in Turkish coffee were elucidated for the first time. Pyrazine compounds were carried out by the application of gas chromatography-mass spectrometry (GC-MS). A total of nine pyrazine compounds were detected in the samples. According to the results, the samples brewed in a copper pot in hot sand had the highest amount of pyrazines followed by SSP and ACM. 2-Methylpyrazine was found in abundance in all three samples while 2,5-dimethylpyrazine and 3-ethyl-2,5-dimethylpyrazine were the other substantial compounds. In contrast with the pyrazine formation in samples, ACM had a considerable amount of total phenolics and antioxidant activity followed by SSP and CPS. This may result from the less boiling time in ACM (around 90 seconds) which prevented the degradation of phenolics to an extent.