Unified mint quantitation: Development of a high-throughput analysis for the quantitation of key aroma compounds in mint

Essential oils of the genus Mentha are extensively used as flavour ingredients in the food, cosmetic and pharmaceutical industry. To avoid the very time and labour-intensive traditional flavour analysis comprising isolation by solvent assisted flavour extraction and comprehensive GC-MS analysis, a new high-throughput approach based on a bead-beater homogenisation followed by SIDA-LC MS/MS has been developed. While terpenes could be directly detected using atmospheric pressure chemical ionisation (APCI), alcohols and carbonyls compounds were quantified following specific derivatisations. For example, the reaction of carbonyl compounds such as menthone and (R,S)-carvone with 3-nitrophenylhydrazine [1] enabled their highly sensitive detection by means of electrospray ionisation. In total, over 50 odour-active analytes responsible for the characteristic flavour of mint could be quantified using fast and robust UHPLC-MS/MS methods in small sample amounts such as a single mint leaf. Application of this procedure to more than 150 different genotypes of the genus Mentha enabled the mapping of flavour alterations depending on e.g. growth stages or environmental conditions.