Influence of extraction temperature on the final quality of espresso coffee

The final quality of espresso coffee (EC) depends upon certain technical conditions, such as the extraction temperature used in preparing it. The aim of this work was to investigate the effects of water temperature (88, 92, 96 and 98degreesC) on the final quality of three types of EC (Arabica, Robusta Natural blend and Robusta Torrefacto blend) in order to select the optimal temperature. Volatile compound (analysed by Static headspace gas chromatography/mass spectrometry) and sensory flavour profiles were the most relevant parameters, whereas physicochemical, taste and mouthfeel parameters were not very useful for selecting the water temperature. For Arabica and Robusta Natural blend ECs, 92degreesC was the optimal water temperature. For Robusta Torrefacto blend EC the overall acceptability might lead to the selection of 88degreesC as the ideal water temperature, but the high percentages of key odorants related to roasty and earthy/musty flavours and the 'not hot enough' perception dictated the selection of 92degreesC in this case as well. (C) 2003 Society of Chemical Industry.