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.