Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2006
Publication Date: 6/1/2006
Citation: Plotto, A., Barnes, K.W., Goodner, K.L. 2006. Specific anosmia observed for B-ionone, but not for a-ionone: significance for flavor research. Journal of Food Science. 71(5):S401-S406. Interpretive Summary: Thresholds of aroma volatile compounds indicate how much it takes of that specific compound to be perceived. Knowing the thresholds of flavor compounds is valuable because it indicates whether a flavor compound is contributing to a food aroma or not. Most flavor compounds are usually perceived by a population within the same range. However, in this study, it was found that threshold for ß-ionone was about 5,000 times higher for 50% of the panelists tested. That is, for 50% of the population, it takes 5,000 more of ß-ionone in a food to be perceived. ß-Ionone has a characteristic odor of violet, and it is also present in large amount in raspberries. It is present in many fruit at very small concentrations. Interestingly, the isomer of ß-ionone, a-ionone, did not show such trend, and was perceived at the same level for all the panelists. Another compound, also found in many fruit, ß-damascenone, was perceived 700 times higher for some panelists when it was tested in orange juice, but there were no such differences when it was tested in water. These findings are of great significance for food flavorists: if they use the threshold values found with non-perceivers to create a flavor, that flavor will be, and maybe objectionable to perceivers. On the other hand, if they use the threshold values found for perceivers, non-perceivers will not enjoy the targeted flavor.
Technical Abstract: In the context of measuring thresholds of orange flavor compounds in a deodorized orange juice matrix, it was found that 50% of panelists could not perceive ß-ionone or ß-damascenone as well as the other panelists. Orthonasal and retronasal thresholds for ß-ionone were respectively, 985 and 490 times higher for non-perceivers than perceivers. For ß-damascenone, the ratios were 690 and 390 times higher for ortho-and retronasal thresholds, respectively. Panelists who could not perceive ß-ionone were otherwise good perceivers of most compounds tested. There were no such differences for a-ionone, a constitutional isomer of ß-ionone. All three compounds were re-tested in water using the same panelists. Differences between non-perceivers and perceivers of ß-ionone were 4900 and 4600 times higher for ortho-and retronasal thresholds for non-perceivers, respectively. However, for ß-damascenone, no such differences were found when measured in water. The same panelists could be classified as “perceivers” or “non-perceivers” when ß-ionone was tested in deodorized orange juice or in water. A different panel was used to confirm ß-ionone and ß-damascenone thresholds in water. A greater difference between perceivers and non-perceivers was found for ß-ionone; like with the first panel, there were no differences in sensitivity to ß-damascenone between panelists when the compound was tested in water.