Identification Of Honey And Propolis Varieties Based On Various Spectral Techniques

With the improvement of people’s living standards and enhanced awareness of health, honey and propolis, as kind of health product with high nutritional values, are very popular for consumers. The price and health function of honey and propolis also have some difference because of the different species and the composition. However, the quality of honey is not satisfied in recent years, especially in the floral origin, identification and adulteration, not only harm the interests of consumers, but also affect the development of apiculture. Therefore, the variety of honey and propolis identification has been heavily promoted by the consumers and regulators. However, in our countrt study on technologies of identifying varieties of honeys and propolis is still at an early stage so far. Aiming at this problem, in this paper, a range of technologies including MIR, Raman, NMR and NIR were developed in order to establish rapid analysis methods for classification different varieties of honeys and propolis. According to comparing the results of classification of different varieties of honey and propolis by spectral techniques, effective identification methods were screened to provide the key technicals support for honeys and propolis quality and safety.1. Mid infrared spectra(MIRS) analysis combined with chemometrics was developed to discriminate the botanical origin of five varieties honeys. The overall correct classification rates of calibration and cross-validation of litchi honey, acacia honey, rape honey honey, vitex honey and linden honey by Canonical Discrimination Analysis models(CDA) were 97.9% and 96.6%, respectively. The correct classification for litchi honey, vitex honey and rape honey is relatively high. The correct classification rates of calibration and the cross-validation for litchi honey, vitex honey and rape honey were all reached 98%. Therefore, MIRS can be discriminate of litchi honey, vitex honey and rape honey, availably.2. Raman spectra analysis combined with chemometrics was developed to discriminate the botanical origin of five varieties honeys. The overall correct classification rates of calibration and cross-validation of CDA models for the five varieties were 90.9% and 87.3%, respectively; the correct classification rates of calibration for acacia honey and rape honey were more than 90%. The center of vitex honey, acacia honey and rape honey can be separated clearly. The correct classification rates of calibration and validation for acacia honey and rape honey were more than 98% by CDA; the correct classification rates of calibration and validation for acacia honey and rape honey were more than 83% by PLS-DA. No matter in CDA models and PLS-DA models, the correct classification rate for vitex honey is a latter power. The results showed that Raman spectroscopy is not only feasible but also practical of identification for botanical origins of acacia honey and rape honey.3. Nuclear magnetic resonance spectra(NMRS) analysis combined with chemometrics was developed to discriminate the botanical origin of five varieties honeys. The overall correct classification rates of calibration and cross validation of CDA were 96.9% and 94.4%, respectively, and the center of vitex honey, acacia honey and linden honey can be separated clearly. The correct classification rates of calibration and cross validation by CDA models for linden honey were reached 100% and for acacia honey and rape honey were more than 93%. The results showed that NMR spectroscopy can be used for classification of the five types of honeys, especially for linden honey acacia honey and rape honey.4. Near infrared spectra(NIRS) analysis combined with chemometrics was developed to discriminate the botanical origin of three varieties propolis. The overall correct classification rates of calibration and validation sets by MD-DA were 93.6% and 82.6%, respectively,only the correct classification rates for poplar propolis is power. The overall correct classification rates of calibration and validation by CDA were 91.4% and 88.6%, respectively. Only the classification rates of the birch propolis were 84.2% and 78.9%, respectively, which were lower than the other sets. Therefore, the technology of NIR can be identificated for the three varieties of propolis.5. Mid infrared spectra(MIRS) analysis combined with chemometrics was developed to discriminate the authenticity of propolis. The overall correct classification rates by CDA in calibration and cross validation were 97.6% and 96.4%, respectively; the correct classification rates in calibration and validation sets for poplar propolis, birch propolis and artificial propolis were more than 90%. Only the birch propolis have a lower classification rates which were 88% and 83.3%, respectively.Therefore, the technology of MIR is feasible to identify poplar propolis, birch propolis and artificial propolis.