Application of Electronic Nose in Quality Evaluation of Propolis

Chinese propolis is derived mainly from the Populus species and their hybrids.Poplar tree glue has been widely used as counterfeit propolis,but no efficient method is currently available for the detection of counterfeit propolis.In the present study,electronic nose was used to detect the odor differences among 71 propolis and poplar tree glue samples collected from 70 bee farms in 17 provinces in China.Propolis and poplar tree glue was distinguished from each other by principal component analysis(PCA).Comparison with discriminant factor analysis(DFA) showed that the quality of propolis from Gansu province greatly differed from that of propolis from other provinces.