Multivariate GC-MS data analysis of the apolar fraction of brown propolis produced in southern Brazil

Abstract

In this study, a total of thirty-nine propolis samples from southern Brazil were extracted with diethylether and investigated by Gas Chromatography – Mass Spectrometry (GC – MS). The objective of this study was first to contribute to the elucidation of the chemical composition of brown propolis produced in southern Brazil through investigation of the chemical profile of its apolar fraction and second to investigate if the GC – MS of apolar propolis extracts combine with multivariate analysis may help in origin discrimination of brown propolis. Fifty-three compounds were tentatively identified and were classified into the following classes: alcohols (9), hydrocarbons (9), aliphatic acids (4), aromatic acids (10), esters (1), phenylpropanoids (1), terpenes (15), aldehydes (1) and anthraquinones (1). Resinic terpenes such as pimaric, isopimaric, dehydroabietic and abietic acids were the most abundant and recurrent compounds in the investigated samples. GC – MS based iPLS-DA (Partial Least Squares - Discriminant Analysis) model correctly discriminated propolis produced in different regions of Paraná state. It was concluded that the whole GC – MS profile of apolar extracts of brown propolis combined with multivariate analysis is an auxiliary tool for geographic origin authentication of propolis produced within the state of Paraná.

Keywords:

• Propolis
• semi-volatile and nonvolatile compounds
• PLS-DA
• chemometrics
• origin discrimination

Acknowledgements

We are grateful to beekeepers who kindly supplied the propolis samples.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This work was supported by the “Coordenação de Aperfeiçoamento de Pessoal de Nível Superior” (CAPES)—[Grant 001]; “Conselho Nacional de Desenvolvimento Científico e Tecnológico” (CNPq),—[Grant 407979/2018-2]; “Programa Institucional de Pesquisa Básica e Aplicada da Fundação Araucária”—[17/17FA], and “Financiadora de Estudos e Projetos” (FINEP)/Brazil.