Evaluation of the Character Impact Odorants in Fresh Strawberry Juice by Quantitative Measurements and Sensory Studies on Model Mixtures

Twelve odorants, previously identified with high flavor dilution (FD) factors, were quantified in a fresh strawberry juice by using stable isotope dilution assays. Calculation of odor activity values (ratio of concentration to odor threshold), on the basis of odor thresholds in water, revealed especially the six compounds (Z)-3-hexenal (green), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like, sweet), methyl butanoate (fruity), ethyl butanoate (fruity), methyl 2-methylpropanoate (fruity), and 2,3-butanedione (buttery) as the key flavor compounds in the typical strawberry-like odor of the juice. These results were corroborated by the following sensory experiments: A mixture of the 12 most potent odorants added to a model juice matrix, consisting of pectin, sugars, and nonvolatile acids, in concentrations equal to those in the fresh juice, resulted in an overall odor profile very similar to that of the fresh juice. Furthermore, comparison of the overall odors of 11 model mixtures lacking in 1 of the 12 odorants under investigation, with the odor evoked by the complete set of odorants, showed a clear flavor difference, especially when 4-hydroxy-2,5-dimethyl-3(2H)-furanone, (Z)-3-hexenal, or methyl butanoate was lacking in the mixture. Keywords: Strawberry odor; stable isotope dilution assay; odor activity value; sensory study; 13C2-2,3-butanedione; 2H3methyl butanoate; 2H3methyl 2-methylbutanoate; 2H3ethyl butanoate; 2H3-4-methoxy-2,5-dimethyl-3(2H)-furanone