Profiling chicory sesquiterpene lactones by high resolution mass spectrometry

•A new high-resolution mass spectrometry method to study sesquiterpene lactones (SLs) in chicory was developed.•The method is suitable to obtain a detailed fingerprint of this class of metabolites.•Eight SLs were quantified highlighting significant differences among the varieties.•The concentration of SLs paralleled the bitterness of the varieties investigated.

Sesquiterpene lactones (SLs) are the main determinants of radicchio bitterness and the control of their concentrations is a key point for the market value of this product. An innovative analytical approach based on two complementary mass spectrometers, Orbitrap-HRMS and MS/MS, was used for quantitative analysis of SLs in aerial part of four different varieties of chicory. Data highlighted the presence of eight SLs: 11β,13-dihydrolactucin, lactucin, 8-deoxy-lactucin, dihydro-8-deoxylactucin, dihydrolactucopicrin, lactucopicrin, lactuside C (jaquinellin glucoside) and dihydro-lactucopicrin oxalate. Significant varietal differences were found. The highest amount of SLs was found in the radicchio “Treviso Precoce” variety (189.71 μg/g), the lowest amount in “Treviso Tardivo” variety (45.78 μg/g). Lactucopicrin was the most abundant compound with concentration ranged between 99.36 in “Treviso Precoce” and 13.50 μg/g in “Treviso Tardivo” while dihydro-lactucopicrin oxalate was the less abundant in all analyzed varieties with an average concentration of about 1% on the total amount of SLs.