Identification And Sensory Evaluation Of Floral Volatile Organic Compounds In Cut Chrysanthemum

Chrysanthemum(Chrysanthemum morifolium)has a long history of cultivation and has always been loved by people.It is widely used in gardens and production of cut flowers.Floral scent is one of the important traits of ornamental plants that cannot be ignored.The study on the emission of volatiles and the sensory evaluation of the cut chrysanthemum can provide a basis for the production and application of cut chrysanthemum,and have guiding significance for improving the quality of cut flowers and breeding excellent cut flower varieties.To identify the volatile components of chrysanthemum flowers and perform sensory evaluation of chrysanthemum fragrance,we selected 44 cultivars of chrysanthemum that are routinely used as cut flowers for this thesis research.The main experiments and findings are as follows :1.From the flowers of 44 cut chrysanthemum cultivars,55 volatile compounds were identified by headspace collection combined with GC-MS analysis.These include monoterpenoids,sesquiterpenoids,benzenoids and fatty acid derivatives.Among them,terpenoids were the main volatile components of cut chrysanthemum,especially monoterpenes and oxygen-containing derivatives,which accounted for 55.16 %-100 % of the total volatiles.Among them,sabinene,eucalyptol,camphor,filifolone,terpinolene,chrysanthenone,cis-chrysanthenol acetate,myrtenal and bornyl acetate were the main components of cut chrysanthemum.The results showed that the emission rates of volatiles were different in the different flower types and flower diameters of cut chrysanthemum.When calculated by the fresh weight of the flower,the emission rates of total volatiles and total monoterpenoids in rosette cut chrysanthemum were higher,while the emission rate of sesquiterpenoids in mini cut chrysanthemum was higher;the emission rates of various volatiles in cut chrysanthemums with flower diameters below 40 mm were higher overall.In the correlation analysis between the total emission rate of various volatiles and flower diameter,the negative correlation between the total emission rate of various volatiles and flower diameter was weak when the flower fresh weight was calculated;while the emission rates of total volatiles,total monoterpenoids and total sesquiterpenoids were positively correlated with flower diameter based on flower number.PCA analysis showed that the 9 main volatiles could divide 44 cultivars of cut chrysanthemum into 3 groups,and the aroma types of cut chrysanthemum of various flower types were scattered without aggregation.According to the hierarchical cluster analysis of the volatile components of each variety,44 cut chrysanthemum materials were divided into 6 groups with each group containing different main volatile components and the proportion of total volatiles.2.The sensory evaluation results of 44 cut chrysanthemums showed that the aroma properties and intensity distribution of cut chrysanthemums were relatively dispersed when floral,fruity,grassy,woody,sour and minty aromas were used as six sensory attributes and no(0),light(0 – 3),medium(3 – 6)and concentrated(6 – 9)aroma intensity levels were used as the basis for sensory evaluation.Most varieties were light or medium aroma,only ‘Nannongchengdiandian’ showed strong aroma in floral attribute,and the aroma intensity of each variety in the same flower pattern was also different.The distribution of wind type,mini type and pine needle type cut chrysanthemums was relatively concentrated.Among them,the wind type was more floral and sour,with a medium fragrance;the mini type was more floral,sour and woody and all have a medium fragrance;while the pine needle type was more floral and woody,with a light fragrance.In the correlation analysis of volatile compounds and sensory attributes,it could be seen that camphor was important for six aroma attributes,and it was positively correlated with fruity,grassy and minty aroma,while negatively correlated with floral,woody and sour aroma.Endo-borneol was only important for grassy aroma.The volatile compounds that were important to the three attributes of floral,woody and sour fragrance were the same,and benzaldehyde and benzeneacetaldehyde were positively correlated with them.