Composition of rugosa rose (Rosa rugosa thunb.) hydrolate according to the time of distillation

Rugosa rose (Rosa rugosa Thunb.) is one of the most common rose species in Poland. It has mild soil and climate requirements and is resistant to low temperatures. Rugosa rose hips are a valuable raw material used in food and pharmaceutical industries, while flowers and petals may be a source of fragrant products, such as essential oil and hydrolate. The main aim of this study was to verify usefulness of dried R. rugosa petals for essential oil and hydrolate production. We also assessed the use of rugosa rose petals remaining after oil distillation for hydrolate production.The R. rugosa dried petals immersed in water were subjected to simple distillation and five fractions of primary rose hydrolate were obtained. In parallel, essential oil from the second sample of petals was obtained by hydrodistillation in Clevenger-type apparatus. The distillation residue was used for obtaining four fractions of secondary hydrolate. The volatiles from hydrolate fractions were isolated by liquid–liquid extraction with diethyl ether. The essential oil and hydrolate volatiles were analyzed by GC–FID–MS.Hydrolate fractions contained similar amounts of volatiles (20–30mg/L) with the exception of the first fraction of primary hydrolate (60mg/L). β-Phenylethanol, citronellol, geraniol, and nerol were the main volatile constituents of primary hydrolate. β-Phenylethanol, citronellic acid, and geranic acid were the main volatile constituents of secondary hydrolate. The content of alcohols decreased, while the content of monoterpene esters (citronellyl, neryl, and geranyl acetate) as well as monoterpene acids (citronellic, neric, and geranic acid) increased in successive fractions of both hydrolates.The scent and composition of essential oil and hydrolate obtained from R. rugosa petals were similar to those of rose oil and rose water produced from damask rose (Rosa damascena Mill.). This proves, that rugosa rose distillation products may become an alternative to fragrant damask rose products.