Sensory Quantification And Interaction Study Of Mint Aroma Compounds

Mint is an aromatic medicinal plant with unique aroma and high economic value.Based on gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometer(GC-O),the main aroma components of mint have been resolved.Although we have a clear understanding of the key aroma molecules in mint aroma,there is no definitive experimental evidence on how these aroma molecules interact and form characteristic aromas.Our perception of odor is mainly reflected in aroma intensity,pleasantness and aroma quality,and this study will quantify these perceptions to lay the foundation for further understanding of the aroma formation mechanism.After the establishment of the aroma intensity scale and aroma intensity measurements,the concentration-intensity modeling was performed using Stevens’ law and Hill’s model,respectively,and the results showed that the Hill’s model had a better fit,but Stevens’ law was easier to operate and more practical.After that,the S-curve and σ-τ plot methods were used for the determination of the interactions between binary mixtures,respectively,and the results of both were not consistent,which indicated that the interactions near the threshold and at moderate to high intensities were not completely consistent.In the measurement of the pleasantness,the present study found that the pleasantness would show a trend of increasing and then decreasing or stabilizing with concentration,where menthofuran would decrease much faster than the other six compounds after reaching the highest point of pleasantness.The pleasantness of binary mixtures can be predicted by using the response surface experimental design method,and the final model obtained has a good fit.The sensory similarity may be higher when the compounds are structurally similar,but this is not absolute.For example,the chemical structures of L-menthol,L-menthone and isomenthone are similar and the sensory similarity between them is higher,while the structural similarity between menthyl acetate and L-menthol is not high,but the sensory similarity between them exceeds that between L-menthol and L-menthone.In addition,two compounds with similar perceptions may also differ significantly when they are compared separately with another compound in terms of perceptual similarity.In the measurement of similarity,it is generally necessary to adjust the aroma intensities of the compounds to the same level,which is a tedious process,and Pearson’s r value with the help of relative deviation of aroma intensity and similarity may be a more convenient method.Finally,this study investigated the differences in sensitivity and decision criteria between individuals using a signal detection theory approach.