[Application of ICP-MS to Identify the Botanic Source of Characteristic Honey in South Yunnan].

By adopting inductively coupled plasma mass spectrometry (ICP-MS) combined with chemometric analysis technology, 23 kinds of minerals in four kinds of characteristic honey derived from Yunnan province were analyzed. The result showed that 21 kinds of mineral elements, namely Na, Mg, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sb, Ba, Tl and Pb, have significant differences among different varieties of honey. The results of principal component analysis (PCA) showed that the cumulative variance contribution rate of the first four main components reached 77.74%, seven kinds of elements (Mg, Ca, Mn, Co, Sr, Cd, Ba) from the first main component contained most of the honey information. Through the stepwise discriminant analysis, seven kinds of elements (Mg, K, Ca, Cr, Mn, Sr, Pb) were filtered. out and used to establish the discriminant function model, and the correct classification rates of the proposed model reached 90% and 86.7%, respectively, which showed elements contents could be effectively indicators to discriminate the four kinds characteristic honey in southern Yunnan Province. In view of all the honey samples were harvested from apiaries located at south Yunnan Province where have similar climate, soil and other environment conditions, the differences of the mineral elements contents for the honey samples mainly due to their corresponding nectariferous plant. Therefore, it is feasible to identify honey botanical source through the differences of mineral elements.

[A Feasibility Study on the Discrimination of the Propolis Varieties Based on Near Infrared Spectroscopy].

Botanical origins of propolis are significant factors affecting biological and pharmacological activities because of different components in propolis. Until now, the determination of propolis botanical origins is mainly based on different varieties and the content of the compositions with great limitations. Therefore, it is important to discriminate different botanical origins of propolis quickly and accurately. In this study, Near-infrared (NIR) spectra of propolis varieties based on principal component analysis mahalanobis distance (PCA-mahalanobis distance) model and canonical discriminant analysis model were built for the classification of three botanical origins (poplar propolis，brich propolis and rubber propolis). The models were built based on the optimal pretreatment method and bands of first derivative + Savitzky-Golay (7) filter and 4500~12 000-1, which were selected in advance. After the principal component analysis, the correct classification rates of calibration sets and validation sets in analysis mahalanobis distance models were 93.62% and 82.61%, respectively. The discrimination rate and the cross-validation rate of canonical discrimination models were 91.4% and 88.6%, respectively. Therefore, NIR spectroscopy with chemometric methods is not only feasible but also practical for rapid and accurate identification of varieties of propolis.

[Discrimination of Rice Syrup Adulterant of Acacia Honey Based Using Near-Infrared Spectroscopy].

At present, the rice syrup as a low price of the sweeteners was often adulterated into acacia honey and the adulterated honeys were sold in honey markets, while there is no suitable and fast method to identify honey adulterated with rice syrup. In this study, Near infrared spectroscopy (NIR) combined with chemometric methods were used to discriminate authenticity of honey. 20 unprocessed acacia honey samples from the different honey producing areas, mixed? with different proportion of rice syrup, were prepared of seven different concentration gradient? including 121 samples. The near infrared spectrum (NIR) instrument and spectrum processing software have been applied in the? spectrum? scanning and data conversion on adulterant samples, respectively. Then it was analyzed by Principal component analysis (PCA) and canonical discriminant analysis methods in order to discriminating adulterated honey. The results showed that after principal components analysis, the first two principal components accounted for 97.23% of total variation, but the regionalism of the score plot of the first two PCs was not obvious, so the canonical discriminant analysis was used to make the further discrimination, all samples had been discriminated correctly, the first two discriminant functions accounted for 91.6% among the six canonical discriminant functions, Then the different concentration of adulterant samples can be discriminated correctly, it illustrate that canonical discriminant analysis method combined with NIR spectroscopy is not only feasible but also practical for rapid and effective discriminate of the rice syrup adulterant of acacia honey.

[Application of inductively coupled plasma mass spectrometry with chemometric methods in classification of honeys according to their types].

In order to identify honeys according to their floral origin, inductively coupled plasma mass spectrometry (ICP-MS) combined with principal component analysis (PCA) and discriminant analysis (DA) were employed in the present study. Three kinds of honeys such as acacia honey samples, sunflower honey samples and rape honey samples were selected. It was pretreated by wet-acid digestionand measured 20 kinds of mineral elements in honey samples by ICP-MS. The result showed that the accuracy of the inductively coupled plasma mass spectrometrymeted the requirements. The result of principal component analysis demonstrated that the acacia honey samples were performed a trend of certain gather. The trend of the sunflower honey samples and the rape honey samples are not obvious. Ten kinds of mineral elements including Na, Mg, K, Ca, Sr, Ba, V, Fe, Ni, Sb can be regarded as honey varieties of characteristic elements. Seven kinds of mineral elements such as Mg, Sr, Ba, Sb, Ni, Cr and Na could be selected through stepwise discriminant analysis. Using bayes discriminant analysis, A linear discriminant function can be recieved. The discrimination rate of honey samples such as acacia honey samples, sunflower samples and rape honey samples were 100%, 80% and 90. 9% respectively. Two sunflower honey samples was misclassified into rape honey samples an-done rape honey samples are also misclassified into acacia honey sample. The total rate of discriminant model cross validation was 90. 3%. It is concluded that the mineral elements in honey varieties with good classification. The present study can provide theoretical basis and the relationship between thetypes of honey samples with mineral elements. The method what this study used had simple, accurate and stablecharacteristics, which can be used as a reliable method of honey sample identification.

[Determination of adulteration in honey using near-infrared spectroscopy].

The objective of the present research is to study the potential of using Fourier transform near-infrared spectroscopy (FT-NIR) in conjunction with discriminant partial least squares (DPLS) chemometric techniques for the discrimination of honey authenticity. First, seventy one commercial honey samples from Chinese market were analyzed to detect the levels of honey adulteration by stable carbon isotope ratio and the chemical result showed that the samples include unadulterated (n = 27) and adulterated (n = 44) products. The samples were scanned in the spectral region between 4 000 and 11 000 cm(-1) by FT-NIR spectrometer with an optic fiber of 2 mm path-length and an InGaAs detector and then divided randomly five times into two sets, namely calibration sets and validation sets, respectively. Five kinds of mathematic models of honey samples were established for classification of honeys as authentic or adulterated by using DPLS. Different spectra pretreatment methods, spectral range and different principal component factors were selected to optimize the calibration models. The calibration models were successfully validated with exterior cross-validation methods. Through comparison analysis of the results, the overall corrected identification rate of authentic and adulterated honey samples in five calibration models were 91.49%, 94.68%, 92.98%, 93.86% and 94.87%, respectively. The correct classification rate of the validation samples was 93.75%, 89.58%, 89.29%, 92.31% and 86.96% from model one to model five, respectively and 100% of adulterated honey samples were correctly identified and classified in validation models 2, 3 and 4. The results demonstrated that FT-NIR together with DPLS could be used as a rapid and cost-efficient screening tool for discrimination of commercial honey adulteration, and the analytical technique would be significant to Chinese honey quality supervision.

[Application of ICP-MS to detection of trace elements and heavy metals in different kinds of honey].

Honey contains abundant trace elements, which are important nutritional elements for human health, but the difference between different species has not been reported. Seven kinds of trace elements and five kinds of heavy metals in different honey species were analyzed by the method of ICP-MS. The results showed that honey contained many wholesome elements, such as Ca, Fe, Zn, Mn, Cu, Se and Mo, but there was great difference between different species. The highest concentrations of Ca, Fe, Zn, Mn, Cu, Se and Mo were 132.79 micorg x g(-1) x FW (jujube flower honey), 24. 38 microg x g(-1) x FW (medlar flower honey), 4.60 microg x g(-1) x FW (balsam pear flower honey), 2930.10 ng x g(-1) x FW (balsam pear flower honey), 480. 02 ng x g(-1) x FW (lychee flower honey), 29.39 ng x g(-1) x FW (lychee flower honey) and 3. 45 ng x g(-1) x FW (medlar flower honey) respectively. Honey contains little heavy metals, the concentrations of As and Pb are below 30 ng x g(-1) FW, and those of Hg, Cd and Cr are not higher than 10 ng x g(-1) x FW. The conclusion is that honey is a wholesome and safe food.