Evaluation of phytochemical diversity of cinnamomum verum j.presl in South India

Abstract

Cinnamon, obtained from the inner bark of Cinnamomum verum J. S. Presl (Syn. C. zeylanicum Blume), is the second largest spice used in the world. There are several ambiguities regarding the origin, distribution, diversity and authenticity of Cinnamonand the present study evaluates the intra species diversity of C. verum distributed in south India through morphological, phytochemical and genetic analyses. Field study was conducted across south India and revealed that cinnamon (C. verum) is naturalized especially in homesteads of Kerala. Large scale plantations were rare and it is suggested to take initiatives to protect existing plantations as a genetic pool and also to promote large scale cultivation of cinnamon in Kerala to get good quality cinnamon. Morphological characters of leaves including qualitative and quantitative characteristics were evaluated and variations were observed among different accessions. The interspecies chemical diversity was studied based on volatile as well as non volatile chemical profiling. HPTLC analysis was carried out to determine presence of marker compounds in solvent extracts, while GC-MS analysis of essential oils were carried out for volatile chemical profiling. The chemical profiles showed significant variation between the accessions and were grouped in to different clads based on their chemical compositions. Content oftoxiccoumarin, which is a benchmark in the authenticity of cinnamon, was evaluated and results showed that authentic sample contain negligible or below detection limit of coumarin compared to market samples and cassia cinnamon. The genetic diversity was also analyzed among the different accessions of cinnamon collected. Highly polymorphic, four ISSR primers were used for genetical study and the genetic diversity was assessed using dendrogram that grouped 12 accessions in to 4 groups. The results revealed the existence of variation within the studied cinnamon accessions which may be caused by cross pollination, and due to the influence of other biogeographic conditions. The accession collected from the remaining of Cinnamon plantation at Ancharakkandy, Kannur emerged as a promising accession with favorable flavor qualities.