Characterization of aroma-impact compounds in yerba mate (Ilex paraguariensis) using GC-olfactometry and GC-MS

The volatile compounds of 18 yerba mate (YM) commercial brands from Argentina, Brazil, P.araguay and Uruguay were extracted using a Likens-Nickerson simultaneous distillation-extraction (SDE) apparatus, and analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that a total of 35 major volatile compounds were identified by GC-MS: among them, norisoprenoid compounds. A principal component analysis (PCA) was carried out in order to ascertain the degree of differentiation between samples and which compounds were involved. The results showed three main groups of YM corresponding to the places where they are commercialized. The first group (samples from Paraguay and Argentina) correlated positively with 6-methyl-5-hepten-2-one, octanal and 1-octanol. The second group (YM marketed in Uruguay but produced in Brazil) correlated positively with alpha- and beta-ionone, linalool, nerol, alpha-terpineol, (Z)-linalool oxide and the aliphatic hydrocarbons undecane, dodecane and heptadecane. The third group (YM produced and marketed in Brazil) correlated positively with 2,4-heptadienal isomers, (E)-linalool oxide and beta-cyclocitral. Through a preference test, one commercial brand was selected to be analyzed by gas chromatography-olfactometry (GC-O). Sixteen odor active compounds were perceived by GC-O analysis. It seems that the norisoprenoid compounds and components produced by fatty acid degradation play a vital role in the special aroma of yerba mate. (C) 2013 Elsevier Ltd. All rights reserved.