Study On The Synergism Of Aroma Compounds In Flowers And Fruits

As an important part of food additives,natural products of flower and fruit are very popular with people.Their flavors and fragrances are widely used in food,medicine,tobacco,textile,leather,paper making,and so on,which are closely related to national economy and people's life.At present,most of the flower and fruit flavor products developed by China are characterized by their lack of harmony,fidelity and natural sense,which seriously hamper the rapid development of spices and fragrances and their related industries in China.In this paper,by combining experimental research with theoretical analysis,a method for the determination of trace key aroma compounds in natural fruits and flowers(jujube,peach,apple,rose,lavender)was established by gas chromatography-mass spectrometry(GC-MS).At the same time,based on the new method of synergistic effect,the interaction between different aroma compounds and notes was explored.Then,the relationship between the molecular structure characteristics of aroma compounds and synergistic effect was summarized.Moreover,the inherent law of synergistic effect of different aroma compounds was found out,so as to realize the effective regulation of the characteristic aroma of flowers and fruits.In the research,SPME,TDS and steam distillation were compared to study the aroma compounds of jujube.It was found that SPME was the best method.The reliability of SPMEGC-MS was investigated from the aspects of linear range,detection limit,quantitative limit and recovery rate.The final results showed that the method could accurately and effectively analyze the aroma compounds in flowers and fruits.Furthermore,the overlapping peaks in jujube and rose were separated based on visualization deconvolution technology,such as the physical properties of 2,3-butanedione and pentanal,citronellal and neroli ether,and multiple overlapping peaks with similar retention time were effectively decomposed.The results showed that visual deconvolution technology could extract and purify a single component from complex matrix,and construct a clean spectrum,which greatly improved the matching accuracy of aroma compounds.Through the above experiments,a new method for rapid and accurate analysis of micro-aroma compounds in flowers and fruits was established.Based on the above new methods,the aroma compounds of flowers and fruits(jujube,peach,apple,rose,lavender)were studied.It was found that hexanal(354.68-764.28 ?g/kg),benzyl alcohol(162.12-578.02 ?g/kg)in jujube,hexanol(2442.54-17991.25 ?g/kg),2-hexenal(2169.55-7077.94 ?g/kg)in peach,(E)-2-hexenal(1375-54 ?g/kg)in apple,linalool acetate(513.11-882.36 mg/kg),linalool(389.82-522.35 mg/kg)in lavender,hexanol(128.34 mg/kg)and phenylethyl acetate(115.14 mg/kg)in rose are the major aroma compounds.GC-O and OAV analysis showed that hexanal(OAV: 39-85;AI: 8.7-9.4),(E)-2-octenal(OAV:32-70;AI:6.5-8.5)in jujube;4-methyl-4-thiyl-2-pentanone(AI: 3.2),?-decalactone(AI: 3.2)in peach;ethyl butanoate(OAV:85-613;AI:7.2-8.5),3-methyl butanal(OAV:2-7;AI:2.3-5.4);linalool(AI:5.9-6.7)and linaloyl acetate(AI: 6.2-7.7)in lavender;?-damascone(FD: 256)and geraniol(FD: 256)were the main aroma contributing compounds.Based on the new method of interaction between different aroma compounds and notes of fruits and flowers,the interaction of aroma compounds in jujube,peach,apple,rose and lavender was studied.It was found that the aroma compounds with the same structure or similar aroma were more likely to have synergistic and additive effects,while the aroma compounds with different structures often had masking effects.For example,when 2,5-dimethylpyrazine is combined with 2-methoxy-3,5-dimethylpyrazine,hexanal and(E)-2-hexenal,the ratio of experimental to theoretical threshold is less than 0.5,showing a strong synergistic effect;while when 2,5-dimethylpyrazine is combined with(E)-2-hexenal,?-octalactone and 2,5-dimethylpyrazine,hexanal and hexanoic acid,the ratio of experimental to theoretical threshold is larger.The values were 3.83,3.38 and 2.24,respectively,which indicated that there was obvious mutual masking effect between them.Steven model(n index)was used to study the relationship between aroma compounds.The results showed that when the subtract of n value of aroma compounds was between 0 and 0.1,the synergistic effects were basically shown,such as ?-decalactone and ?-decalactone(0.07),geranyl acetone and citronellol(0.06),(E)-2-hexenal and(E)-2-heptanal(0.04).While the subtract of n value was greater than 0.1 and less than 0.2,most of them showed additions effect,such as hexanol and ethyl acetate(0.15),leaf alcohol and 1-octene-3-one(0.2),lavender acetate and hexyl butanoate(0.14).While the subtract of n value was greater than 0.2,they basically showed masking effects,such as 1-octene-3-ol and 2-heptanone(0.26),camphor and 4-terpineol(0.28),3-mercaptohexanol and citronellol(0.3).The dominant aroma model was used to study the relationship between the dominance and the mode of action of aroma compounds.The results showed that the dominant aroma regions of different interaction combinations were different,and the mode of action was highly consistent with the dominance.For example,there is a masking effect between 2-nonone and(E,E)-2,4-hexadienal,and the size and shape of the dominant region are asymmetric,which indicates that the two aroma compounds have strong or weak differences in aroma intensity value and recognition probability,and the probability of correct identification of the two compounds is greatly reduced.There is a synergistic effect between citronellol and geraniol,and their respective dominant regions are similar in size and shape.Symmetrical shape indicates that the two aroma compounds have the same dominant ability,and the probability of identifying them correctly is high.The interaction between notes was studied in the experiment.The results show that different notes often have masking or additive effects.For example,in the S-curve method,the ratio of fruit note to sweet note,fruit note to roast note,sweet note to green note was 0.65,0.68 and 0.59,indicating that there was a strong additive effect between these combinations.When fruit note was combined with sour note,sweet note with sour note,green note with sour note,the ratio between experimental threshold and theoretical threshold was larger,which was 1.58,2.57 and 1.58,indicating that there was a strong masking effect between them.