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The Volatile Composition of Portuguese Propolis Towards its Origin Discrimination

Soraia I. Falcão, Cristina Freire, A. Cristina Figueiredo and Miguel Vilas-Boas

CIMO - Escola Superior Agrária, Instituto Politécnico de Bragança, Campus de Sta. Apolónia, 5300-237 Bragança, Portugal.

REQUIMTE - Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal

Universidade de Lisboa, Faculdade de Ciências de Lisboa, Departamento de Biologia Vegetal, Instituto de Biotecnologia e Bioengenharia, Centro de Biotecnologia Vegetal, C2, Campo Grande, 1749-016 Lisboa, Portugal

Abstract: The volatiles from thirty six propolis samples collected from six different geographical locations in Portugal (mainland, Azores archipelago and Madeira Island) were evaluated. Populus x canadensis Moenchen leaf-buds and Cistus ladanifer L. branches essential oils were comparatively analysed. The essential oils were isolated by hydrodistillation and analysed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). Cluster analysis based on propolis samples volatiles chemical composition defined three main clusters, not related to sample site collection. Cluster I grouped 28 samples with high relative amounts of oxygen-containing sesquiterpenes (20-77%), while cluster II grouped 7 samples rich in oxygen-containing monoterpenes (9-65%) and the only sample from cluster III was monoterpene hydrocarbons rich (26%). Although Populus x canadensis and Cistus ladanifer were associated as resin sources of Portuguese propolis, other Populus species as well as plants like Juniperus genus may contribute to the resin in specific geographical locations.

Keywords: Propolis; volatiles; Populus x canadensis; Cistus ladanifer; GC; GC-MS. © 2015 ACG Publications. All rights reserved.