Title: Uses and Limitations of Thresholds in Flavor Research Authors
Submitted to: Gordon Research Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 30, 2006
Publication Date: N/A
Technical Abstract: Thresholds for flavor volatiles have been used to determine the odor activity or aroma impact of volatile compounds in fruits and other foods. If the measured concentration of a volatile is higher than its sensory threshold, that compound is deemed to contribute to the food flavor. Most commonly used thresholds have been determined in water or air, but they may vary widely in more complex matrices such as milk, gels, or fruit puree. In this study, thresholds of orange juice (OJ) volatile compounds were determined in a deodorized OJ matrix using the Three-Alternative-Forced-Choice (3-AFC) method (ASTM: E-679). Depending on compound solubility in water, odor thresholds were about ten times (esters and some aldehydes) to 60 or 200 times (terpenes and other aldehydes) higher in the OJ matrix than published values in water. From these findings, the odor activity values of volatile compounds in one orange juice study was reconsidered: three out of seven compounds appeared to be not as important to the juice flavor. In addition, partial anosmia was found for ß-ionone, a nor-isoprenoid present in many fruits. Orthonasal thresholds were 985 times higher for half of the panelists (20 subjects) than for the other half, which was not age-dependent. Partial anosmia was further confirmed in water: differences in thresholds were 4,900 times between perceivers and non-perceivers. This indicates that the sensory experience of fruit and food products containing ß-ionone may be very different depending on the (perhaps) genetic ability to perceive this compound.