Evaluation On Edible Value Of Petals Within Five Tree Peonies

Tree Peony(Paeonia suffruticosa Andr.)is a deciduous shrub of Paeonia in Paeoniaceae.It is an important ornamental plant in China,and plays an important role in garden application and flower culture.Besides being ornamental,tree peony petals also contain rich nutrients such as sugar,protein,amino acid,anthocyanins and flavonoids,which can be used as a potential food resource.In this study,five common cultivated species and varieties‘Fengdan',‘Xiangyu',‘Zhaofen',‘Luoyanghong'and‘High Noon'were used as experimental materials to comprehensively evaluate the edible value of tree peony petals based on sensory evaluation,nutrient analysis,antioxidant capacity analysis and acute oral toxicity test.This study was designed to provide a theoretical basis for the consumption of tree peony petals and to provide a basis for the selection of suitable tree peony edible varieties.1.The sensory evaluation analysis of tree peony petals mainly included flower fragrance,color and taste evaluation.The aroma components of tree peony flowers mainly comprised terpenes,alcohols and alkanes.The color characteristic values of petals of different varieties were different.‘Luoyanghong'and‘High Noon'had higher color brightness.The result of taste quality evaluation was‘High Noon'>‘Xiangyu'>‘Luoyanghong'>‘Fengdan'>‘Zhaofen'.2.The nutritional evaluation and analysis of tree peony petals included three aspects:basic nutrients,amino acids and bioactive nutrients.Soluble sugar was the most important basic nutrient of petals,and‘Luoyanghong'and‘High Noon'were higher than other varieties in soluble sugar and starch.The petals of various varieties were rich in mineral elements,among which the contents of phosphorus,potassium,calcium,magnesium and cuprum in‘Fengdan'and‘Xiangyu'were relatively higher,and the content of copper all met the edible standard.There were 16 kinds of amino acids in the petals of all varieties,among which‘Fengdan'had the highest total amino acid content,and‘Xiangyu'had the highest essential amino acid content.Active nutrients,such as total phenols,total flavonoids and total anthocyanins,the contents of‘Luoyanghong'and‘High Noon'were higher than those of other varieties.The activity of SOD was the highest in‘Xiangyu'.3.In vitro antioxidant capacity test of tree peony petals showed that the DPPH⁺scavenging capacity,ABTS⁺scavenging capacity,OH^-scavenging capacity and total antioxidant capacity of‘Luoyanghong'and‘High Noon'were significantly higher than those of other varieties of the concentration range of 0.2—1.2 mg·m L^-1.4.The acute oral toxicity test in mice showed that the maximum oral tolerance dose about all varieties of petals was more than 20 g·kg^-1·bw.The tree peony petals were non-toxi.5.There were great variety differences in the nutrients contained in tree peony petals.Through the analysis of differences among varieties,the evaluation indexes of nutrients in tree peony petals were selected,which were soluble protein,tannin,calcium,magnesium,total phenols,total flavonoids,total anthocyanins,threonine and cysteine.The evaluation order of nutrients of the five varieties was‘Luoyanghong'>‘High Noon'>‘Xiangyu'>‘Zhaofen'>‘Fengdan'.To sum up,tree peony petals had excellent sensory qualities,abundant nutrients and strong antioxidant activity,and could be used as edible flowers.Flowers of purplish red and yellow cultivars could be considered for eating on the basis of the traditional consumption of white and pink tree peony.