Effect of temperature and storage duration of flowers on essential oil content and composition of damask rose (Rosa × damascena Mill.) under western Himalayas

• Storage of flowers at −20 °C did not significantly affect the essential oil yield.
• Oil compositions showed the least alterations at −20 °C up to 20 days.
• Geraniol content decreased with storage duration at 4 ± 0.5 °C.
• Rose flowers can be stored at −20 °C for 20 days.

Present study was conducted to investigate the effect of storage on the quality of damask rose (Rosa × damascena Mill.) flowers in western Himalayas during 2013. Damask rose flowers were harvested and distilled immediately (control), stored at 4 ± 0.5 °C and −20 °C for 10, 20 and 30 days before distillation. The essential oil was obtained by hydro-distillation and analyzed by GC and GC–MS. Storage of flowers under different conditions affected the color of flowers. Essential oil content was not significantly affected by different cold storage treatments (P ≤ 0.05). However, changes in essential oil compositions were observed during cold storage at 4 ± 0.5 °C and −20 °C up to one month as compared with control. Oil compositions represented the least alterations and flowers kept their primary quality when stored at low temperatures, particularly at −20 °C. The rate of geraniol decreased from 19.07 ± 1.25 to 2.29 ± 1.79% with increase in storage period from 10 to 30 days at 4 ± 0.5 °C as compared to control. The concentrations of hydrocarbons like hexadecane, nonadecane, tricosane and docosane in the flowers were increased with increase in storage duration 4 ± 0.5 °C. The optimal results in terms of rose oil content and components were obtained from the immediately distilled rose flowers after harvest as well as from the flowers stored at −20 °C for 20 days.