Determination of volatile thiols in virgin olive oil by derivatisation and LC-HRMS, and relation with sensory attributes

Volatile thiols were determined by derivatisation followed by ESI-LC-HRMS in twenty-five virgin olive oils (VOOs) pertaining to different commercial classes. 4-Methoxy-2-methyl-2-butanethiol (4MMB) was quantified, and 3-methyl-2-butenethiol and methanethiol were identified for the first time in VOO by non-target analysis. In order to evaluate the influence of volatile thiols on VOO aroma, the sensory notes, defects and secondary attributes were determined in samples according to European regulation by an Official VOO Panel. A significant correlation was found between the concentration of 4MMB in VOO samples and the 'fig tree leaf' sensory attribute. To confirm these results, 4MMB odour detection threshold and odour recognition were investigated.