Chemical analysis of Iranian Rosa damascena essential oil, concrete, and absolute oil under different bio-climatic conditions

Rosa damascena Mill., the unique species of Rosaceae, is one of the valuable medicinal and ornamental aromatic plants cultivated in different parts of Iran. Climatic conditions impact the productivity and yield of rose products. This work was designed to study the chemical composition of the essential oil, concrete, and absolute oil of Rosa damascena Mill. (same genotype) collected from three different bio-climatic areas belonging to semi-arid, cold (Qamsar and Niyasar in Isfahan province), semi-arid, very warm and dusty (Maymand in Fars province), and arid, cold and windy (Lalezar in Kerman province) regions (as important rose growing centers) of Iran for the first time. All R. damascena samples were investigated using GC-FID, and GC-MS methods, to evaluate phytochemical constitutions. The sample yields were in the range of 0.03-0.04 % for essential oil, 0.29-0.40 % for concrete, and 0.07-0.19 % for absolute. The citronellol/geraniol ratio (C/G), the main quality determining factor of essential oil, was found to vary from 3.3 % to 6.9 % in essential oil. It was observed that R. damascena growing at semi-arid, cold such as Qamsar had a higher C/G factor, while those growing at the same bio-climatic zone with low altitude, Niyasar, had a lower C/G ratio. Phenyl ethyl alcohol prevailed in Co with 44.5 %, 47.2 %, 45.2 %, and 45.1 % for Qamsar, Niyasar, Meymand, and Lalezar, respectively. On the other hand, GC-MS analysis of absolute oil showed that phenyl ethyl alcohol, citronellol, and phenolic terpenoids are three major components that take more than 60 % of total rose absolute in four areas. Essential oil, concrete, and absolute oil of the Qamsar region were considered to have a high quality in terms of richness in C/G ratio and phenyl ethyl alcohol monoterpenes. The concrete and absolute composition of the residual waste petals (prepared from one of the rose water companies in Qamsar) were also studied, and the results showed that the amount of concrete in the waste petals was relatively significant and could be considered as an important by-product. According to findings, it can be concluded that quantitative and qualitative properties of R. damascena productions are affected by bioclimatic conditions and environmental factors that are useful for optimum production. Some factors and alternative methods affecting in C/G ratio and phenyl ethyl alcohol increasing recommended.

Automated summary

This study analyzed the chemical composition of Rosa damascena from different bioclimatic areas in Iran and found that climatic conditions affected the quantity and quality of rose products. Roses from the Qamsar region had higher citronellol/geraniol ratio and phenyl ethyl alcohol content, indicating higher quality. Additionally, the study discovered that waste petals can be used as an important by-product.