Submitted to: Subtropical Technology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2004
Publication Date: 10/21/2004
Citation: Plotto, A., Margaria, C., Goodner, K.L., Baldwin, E.A. 2004. Threshold values for key aroma components in an orange juice matrix: new findings. Subtropical Technology Conference Proceedings. 55:11-14.
Technical Abstract: Thresholds for flavor volatiles have been traditionally calculated in water or air, but they may vary widely in more complex matrices such as milk, gels, or fruit slurries. The data presented is part of a continuing study to provide the industry with threshold guidelines more adequate for the use of flavors in citrus juices. The objectives include understanding of volatile-matrix interactions. Thresholds of key aroma compounds of orange juice (OJ) were determined in a deodorized OJ matrix. The Three-Alternative-Forced-Choice (3-AFC) method was used (ASTM: E-679). Sixteen to twenty experienced panelists were presented with orange juice samples arranged in five rows of three samples corresponding to five spiking levels, each separated by a factor of 3, with a 3-AFC presentation at each level. For each compound, the test was repeated four times. Odor and taste thresholds for esters were twice (methyl butanoate) to thirty times (ethyl propanoate) higher in the orange juice matrix than published values in water. In comparison, it was found earlier that for non-water soluble compounds, odor thresholds in the juice were 60 to 200 times higher than in water (a-pinene, limonene, a-terpineol, octanal), while for more soluble aldehydes and the terpene-alcohol linalool, the threshold in juice was about 10 times higher than published values in water. Odor thresholds were generally higher than taste thresholds. At sub-threshold concentrations, compounds tended to decrease perception of sweet taste. At supra-threshold, most esters increased fruitiness, but some imparted a spoiled flavor. A binomial distribution was found between panelists for sensitivity to ß-ionone and ß-damascenone, but not to a-ionone, indicating partial anosmia for the former compounds for some individuals. While there was no trend in age or gender for the distribution of ß-ionone, all of the non-perceivers for ß-damascenone were above 46 years old. Results of this study show the importance non-soluble compounds on odor and flavor perception. The threshold values provided by this research is directly applicable by the industry in comparison with the current values that are published in water.