Application of Untargeted Metabolomics to Determine Volatile Compounds from the Spanish Plant Arctostaphylos uva-ursi Used as Tea

Abstract

One-hundred and seven different volatile compounds were identified in the samples of Arctostaphylos uva-ursi collected from nine locations in Spain. This plant is commonly brewed and used as tea. Volatile compounds profile was detected using solid-phase microextraction gas chromatography-mass spectrometry. The most interesting compounds detected from an antioxidant capacity point of view were esters, phenols, and aromatics compounds. All samples were discriminated by principal component analysis. The insolation and altitude of harvest areas, and latent structures were considered for interpretation of results. Discriminant analysis was applied to control the type and concentration of metabolites and determine the best plant antioxidant profiles of volatile compounds from plant origin. Moreover, a heatmap displayed correlations between detected compounds. The discriminant analysis led to 20 quality markers being identified for the analysed plants. The strongest antioxidant capacity was obtained in the samples from Pina de Montalgrao and Loarre (collected in September) for ORAC (33.11 ± 0.61 g Trolox/g sample) and DPPH (IC50 = 711 ± 12 µg/g) methods, respectively. The plant with the highest total phenolic content was Loarre collected in September (171.9 ± 19.4 mg GAE/g DW) and November (177.1 ± 11.0 mg GAE/g DW).