Identification Of The Aroma Compounds In Different Aging Years Of Citri Reticulatae Pericarpium

Citri Reticulatae Pericarpium,mainly including the dried ripe pericarp of Citrus reticulata Blanco and Citrus reticulata 'Chachi',has been a popular traditional genuine medicinal herb with great medicinal values and consumed daily as food.The difference of medicinal efficiency and aroma composition for different aging years of Citri Reticulatae Pericarpium mainly due to the significant difference of composition and contents.At present,almost no relevant reports about the systematic and scientific researches on the acidic and alkaline aroma-active constituents of Citri ReticulataePericarpium could be found.It is important to explain the meaning of "the older the better" for Citri Reticulatae Pericarpium by the systematic researches on the aroma.It is deeply meaningful for the comprehensive application and industrialization of Citri Reticulatae Pericarpium by the research on volatiles in Citri Reticulatae Pericarpium.The main studies on the aroma evaluation and aroma-active components of Citri Reticulatae Pericarpium were summarized as follows:(1)The sensory evaluation of Pericarpium Citri Reticulatae samples of different aging years was carried out.Based on the evaluation,the aroma characteristics of dried tangerine peel were qualitatively described.The differences of aroma of Pericarpium Citri Reticulatae of different aging years were compared and analyzed.There is a significant difference in the intensity of "fruity","oily" and"mouldy" odor.For three and five years of Pericarpium Citri Reticulatae,aroma properties of brewing liquid are significantly improved.And aroma differences of ten years of Pericarpium Citri Reticulatae skin and brewing liquid were not significant.(2)The aroma components of Pericarpium Citri Reticulatae were analyzed by different aroma extraction methods including SDE and SPME.In different aging years,the aroma components of D-limonene were the highest,and ?-terpine was the second.Nerol,2,4-decadienal and neryl acetate were detected only in three-year samples.The relative content of a-sinensal and methyl N-methylanthranilate methyl aminobenzoate was significantly higher than that of other aging years.(3)The volatile aroma substances of Pericarpium Citri Reticulatae were extracted by solvent-assisted flavor extraction technology(SAFE),and the acidic and alkaline aroma active substances in Pericarpium Citri Reticulatae were identified.It was found that the composition of acidic aroma components identified in Pericarpium Citri Reticulatae in three different aging years was slightly different.The composition of acidic aroma components in three and five aging years of Pericarpium Citri Reticulatae was basically the same,but the components including guaiacol(sweet,nutty),undecanal(sweet,floral)and some unknown aroma(potato,fruity and woody)were not detected in ten aging years of Pericarpium Citri Reticulatae.There were no significant differences in the content of basic components in Pericarpium Citri Reticulatae of different aging years,and the aroma-active components contained in three years of Pericarpium Citri Reticulatae were more than five and ten years of Pericarpium Citri Reticulatae,geranyl acetate(earthy,flower),a-selinene(pepper),nerol(floral)and tridecanal(spicy)were not detected in the five-year Pericarpium Citri Reticulatae,terpine-4-ol(herbal),?-ionone(spicy flavor)And a-sinensal(pepper flavor)were not detected in the ten years of Pericarpium Citri Reticulatae.(4)On the basis of SAFE technology,the contribution of aroma active substances was quantified by AEDA,and the key contribution components in different aging years of Pericarpium Citri Reticulatae were determined.For acidic components,phenylacetic acid(floral)had the largest FD factor in the Pericarpium Citri Reticulatae in different aging years,and its contribution to the aroma of Pericarpium Citri Reticulatae was the highest.The common acidic aroma components(FD?81)in different aging years of Pericarpium Citri Reticulatae mainly includes vanillin(vanilla),isovalerate(sweaty),tiglic acid(sweet),unknown(burnt sugar),octanoic acid(sweaty),furaneol(metal taste)and so on.The common alkaline aroma components(FD?81)in different aging years of Pericarpium Citri Reticulatae mainly includes a-pinene(pine),D-limonene(fruity,citrus),phenol(sweet)and carvacrol(spice)and so on.The aroma intensity of camphor(FD = 27,woody)was significantly higher than that of the other two aging years,p-sinensal(pepper)in three and five aging years of Pericarpium Citri Reticulatae(FD=81)was significantly higher than ten years of Pericarpium Citri Reticulatae(FD = 3).