Changes of the Aroma Constituents and Contents in the Course of Rosa rugosa Thunb. Flower Development

【Objective】The changes of the aroma constituents and contents in the course of Rosa rugosa Thunb.flower development were studied.【Method】The aroma constituents and contents present in Rosa rugosa ‘Tang Purple’ during different flower developmental stages were analyzed by means of Head Solid-phase Micro-extraction(HS-SPME) and gas chromatography-mass spectrometry(GC-MS).【Result】Fifty-three compounds were identified in flower bud,including γ-muurolene,α-himachalene,α-pinene,trans-α-bergamotene,cis-3-hexenyl acetate and longiverbenone,terpenes were the major constituents.Sixty-five compounds were identified in fresh flower at the early opening stage,including β-citronellol,citronellol acetate,phenethyl alcohol,geraniol,n-hexyl acetate,nerol,phenethyl acetate and cis-3-hexenyl acetate,alcohols,esters and terpenes were the major constituents.Sixty-two compounds were identified in fresh flower at the half opening stage,including β-citronellol,geraniol,phenethyl alcohol,citronellol acetate,nerol,n-hexyl acetate,phenethyl acetate and α-myrcene,alcohols,esters and terpenes were the major constituents.Sixty-five compounds were identified in fresh flower at the full opening stage,including β-citronellol,citronellol acetate,phenethyl alcohol,geranyl acetate,geraniol,phenethyl acetate,nerol,n-hexyl acetate and α-myrcene,alcohols,esters and terpenes were the major constituents.Fifty-eight compounds were identified in fresh flower at the end of full opening stage,including β-citronellol,phenethyl alcohol,phenethyl acetate,citronellol acetate,α-myrcene,α-pinene,limonene and geranyl acetate,alcohols,esters and terpenes were the major constituents.With the development of rose flower,the content of alcohols increased rapidly,and their maximum concentrations were found at the half opening stage.Esters increased firstly and decreased in succession,and their maximum concentrations were found at the full opening stage.The maximum concentrations of terpenes were found in flower bud,and decreased rapidly at the early opening stage,but they increased again at the end of full opening stage.Aldehydes increased firstly and decreased in succession,their maximum concentrations were found at the full opening stage.【Conclusion】The aroma constituents and contents were distinctly different in different developmental stage of Rosa rugosa Thunb.flower.The main aroma constituents had already formated at the early opening stage,and most of them reached maximum concentration between half to full opening stage.It is concluded that the fresh flowers which are in half to full opening should be plucked when extracting rose essential oil.