Experimental design approach in optimization of some effective variables on quantity and quality extraction of essential oil from Rosa damascena Mill

Having fragrant and useful components, essential oil of Rosa damascena Mill. with the common name of Rose otto is the most expensive and valuable natural aroma products in the world. Different products of R. damascena petals has been known as the most important and basic ingredients or additives in the food, drug, perfume and cosmetic industries in many centuries. Amount of the petals essential oil and its composition is a determining factor of products, made from them. Despite this fact, there is no report about optimization of essential oil extraction from Rosa damascena in the literature. In the present study, the effect of different temperatures (- 5, 0, 5, 10 and 15 degrees C) and duration times of storage (1, 4, 7, 11 and 14 days) on the yield and quality of essential oil extracted from the petals of the mentioned plant was investigated. The response surface methodology (RSM) was used to achieve optimum parameters. It was very interesting to find out storage duration and temperature of 14 days and - 5 degrees C were optimal conditions to obtain maximum extraction yield of 0.0429%, respectively. This means that despite popular belief, petals storage not only does not reduce the extraction yield of essential oil, but also it increases that by up to 1.5 times when the temperature is controlled. Citronellol to geraniol ratio (C/G) was selected as a criterion of essential oil quality. Based on the related standard from International Standard Organization (ISO), the desired ratio of citronellol to geraniol (C/G) is 1.30; therefore, this value was considered as the optimum response. Surprisingly, it was found that the quality of essential oil from short-term fermented petals is higher than those from fresh petals. Storage temperature of about 0 degrees C during 1 day was obtained as the optimum values for attaining the best essential oil quality. Results from this study can pull over public believes about necessity of instant essential oil extraction from harvested petals. Graphic abstract

Automated summary

The study found that under different temperature and storage time conditions, a storage time of 14 days and a temperature of -5 degrees Celsius can obtain the maximum essential oil extraction yield from Rosa damascena petals. The optimum quality of essential oil is achieved when the citronellol to geraniol ratio is 1.30. Additionally, it was surprising to discover that the essential oil quality from short-term fermented petals is higher than those from fresh petals.