Changes in the concentrations of key fruit odorants induced by mastication

Recently, the potent odorants of fresh, hand-squeezed orange juices were characterized by aroma dilution techniques. Quantification using stable isotope dilution assays (SIDA) and calculation of the odor activity values revealed ethyl butanoate, (R)-limonene and (Z)-hex-3-enal among the most potent odorants of the fresh juices. Based on these results a novel approach is proposed to observe the concentration changes of single key odorants occuring during mastication of orange juice. Changes in the concentrations of key odorants were measured by comparing their amounts before and after in-mouth "reactions". This method, designated as SOOM-concept (spit-off odorant measurement) determines the amounts of single odorants lost by certain in-mouth events such as release, adsorption, or chemical modification. Results obtained for orange juice and also model solutions indicated a strong influence of the chemical structure on substance-specific losses.