Investigation geographic origin of Laurus nobilis L. leaves using FTIR, SEM-EDX, and XRD analysis

Abstract

Laurus nobilis L. is a polypragmatic plant with high added value. Leaves collected from different regions in the natural state without breeding have different economic values. In this study, the Geographic Origin and Altitude Effects of Laurus nobilis L. leave samples collected from provinces close to each other were investigated. For this purpose, SEM–EDS was used for morphological characterization of leaves, XRD was used for the characterization of inorganic components and FTIR-ATR was used for the identification of functional groups. By SEM analysis in the samples from Zonguldak region, significant differences were observed in the density of trichomes and glandular plumes more dense and also morphological cell sizes were found to be more large then Kastamonu region. In XRD plot, besides the amorphous state, it has seen that the crystal structure is also present in the structure. The effect of different altitudes on the FTIR spectra of the samples collected according to the provinces was also examined, and no significant difference was observed in the peak positions and intensities in the spectra according to the altitudes. Score plot on ranges of 2800–3000 cm-1 and 750–1800 cm−1 allowed origin of the Laurus nobilis L. discrimination. In order to analysis and classify them according to their geographical origin, FTIR data were combined with chemometric methods using PCA and discriminant analysis. PCA analysis explained 88.7% of the variance in the model. When the results of the discriminant analysis were evaluated, 56 of the 72 samples were classified correctly and 77.8% success was achieved. Both analysis showed that there are differences in the response of the same plant species to their presence in different origins. As a result, FTIR analysis allowed possibility the discrimination of Laurus nobilis L. leaves and in this way it is thought to discriminate of examples for other areas.