Study of composition of espresso coffee prepared from various roast degrees of Coffea arabica L. coffee beans.

•Study of effect of roasting on espresso coffee by PCA analysis of LC/MS data.•Selection of markers showing significant differences among roasting degrees.•Identification of markers by targeted LC/MS2 analysis.•Study of chlorogenic acids, atractylosides and melanoidins profile during roasting.•Design of parameters allowing definite determination of roasting degree.