Study On Methods Of Identifying Botanical And Geographical Origin Of Propolis

The establishment and implementation of agricultural products traceability system is an importantmeasure to guarantee food safety. However, study on technologies of identifying botanical origin andgeographical origin of propolis is still at an early stage so far. Aiming at this problem, in this paper, arange of technologies including colorimeter, HPLC, IR-MS and ICP-MS were developed in order toestablish analysis methods of multicomponent in propolis originated from different plants or regions,provide discussions on feasibility and efficiency of these4technologies, develop forecasting model andverify its reliability. This study will provide key technical support for propolis quality and safetysupervision, and is highly signicant to maintain market order, guarantee of consumers’rights andinterests, promote the development of bee industry.This paper consists of four parts:1. In this part, plants discriminative model based on chrom of propolis alcoholic solution wasestablished. We developed the measuring method of Lab color value of propolis alcoholic solution bycolorimeter,44samples which belong to5different types of propolis were measured.The results ofANOVA showed that there were significant differences in Lab values among5types propolis. Furtherdata processing using stepwise discriminant analysis, and chroma mathematical model of propoliscollected from different plants were built. The classification results were satisfying.86.4%of originalgrouped cases and84.1%of cross-validated grouped cases were correctly classfied, while thepercentage of classifying cases of birch propolis only reached57.1%.2. Plants discriminative technology of HPLC based on flavonoids characteristic was developed.Before qualitative and quantitative analysis of8flavonoids in44samples of5types propolis, weoptimized the national standard method(GB/T19427-2003) of sample pretreatment andchromatographic conditions. The flavonoids analysis results showed that flavonoids barely existed ineucalyptus propolis and rubber propolis(<0.95mg/g), which were totally different from the other threetypes(>44.33mg/g). There were significant differences of flavonoids characteristic between poplarpropolis and brich propolis. Therefore, it was simple to classify these two types by flavonoidscharacteristic.3. In this part, we provided discussions on feasibility and efficiency of δ13C and δ15N forgeographical origin tracing. Firstly the method of simultaneous determination of δ13C and δ15N in grosspropolis was studied, but carbon content in gross propolis was so high that it was hard to achieve undercurrent instrument conditions. Multiple comparison results showed that δ13C value in gross propolisoriginated from6different regions varied significantly, which suggested δ13C value of gross propoliscould be used as an indicator for tracing propolis origin. Compared with gross propolis, δ13C value ofdewaxed propolis was significantly lower, multiple comparison results showed that δ13C value ofdewaxed propolis from different origins changed not so observably than that of gross popolis, so we canmake the conclusion that origin information was lost during the dewaxing process with n-hexne. But ANOVA and multiple comparison results demonstated δ15N value in dewaxed propolis variedsignificantly among6origins, which showed δ15N was an efficient indicator for origin tracing.4. Geographical origin discriminative technology based on multi-element analysis was developed.We studied the pretreatment method of dewaxed propolis for the determination multielements, then75samples from6regions (provinces) were analysed. ANOVA results showed23kinds of elements existedsignificant difference among propolis samples from different regions, which proved it feasible to usemultielement analysis technology to trace propolis origin. The discriminant models were built to furtherstudy the origin discriminant effect. There was an excellent separation between propolis samplesaccording to their origins with the efficiency of linear discriminant analysis model as98.7%and thepercentage of cross-validation discrimination of linear discriminant analysis model as93%, whichshowed that muitielenment indicators were effective for propolis origin tracing.