Headspace aroma and secondary metabolites profiling in 3 Pelargonium taxa using a multiplex approach of SPME-GC/MS and high resolution-UPLC/MS/MS coupled to chemometrics.

BACKGROUND: The present study focuses on the aroma and secondary metabolites profiling of three Pelargonium graveolens cultivars, baladi (GRB), sondos (GRS) and shish (GRSH), grown in Egypt. Utilizing a multiplex approach combining high resolution-ultraperformance liquid chromatography (HR-UPLC)/tandem mass spectrometry (MS/MS) and gas chromatography (GC)-MS coupled with chemometrics, the study aims to identify and profile various secondary metabolites and aroma compounds in these cultivars.

RESULTS: HR-UPLC/MS/MS analysis led to the annotation of 111 secondary metabolites, including phenolics, flavonoids, terpenes and fatty acids, with several compounds being reported for the first time in geranium. Multivariate data analysis identified vinylanisole, dimethoxy-flavonol, and eicosadienoic acid as discriminatory metabolites among the cultivars, particularly distinguishing the GRS cultivar in its phenolics profile. In total, 34 aroma compounds were detected using headspace solid-phase microextraction coupled with GC-MS, including alcohols, esters, ketones, ethers and monoterpene hydrocarbons. The major metabolites contributing to aroma discrimination among the cultivars were β-citronellol in GRB, α-farnesene in GRS and isomenthone in GRSH.

CONCLUSION: The study provides a comprehensive profiling of the secondary metabolites and aroma compounds in the three Pelargonium graveolens cultivars. The GRS cultivar was identified as particularly distinct in both its phenolics and aroma profiles, suggesting its potential as a premium variety for cultivation and use. Future studies should focus on isolating and investigating the newly detected metabolites and exploring the biological effects of these compounds in food applications and other uses. © 2024 Society of Chemical Industry.