Sensory evaluation of the synergism among ester odorants in light aroma-type liquor by odor threshold, aroma intensity and flash GC electronic nose

Although esters were important odorants in light aroma-type liquor, it was still puzzling that sensory interaction between esters made the odor quality of light aroma-type liquor outstanding. The aim of the paper was to investigate perceptual interaction among esters. The odor thresholds of eighteen esters and 35 binary mixture were determined by a three-alternative forced-choice procedure. The relationship between odor threshold and carbon chain length of homologous ethyl esters was investigated. Moreover, 31 binary mixtures present either a synergistic effect or additive action. Furthermore, odor quality and odor intensity were determined by p/τ plot and σ/τ plot, respectively. From the p/τ plot, an ideal sigmoidal function for odor quality was obtained. From the σ/τ plot, for all 120 binary mixtures, just 9 mixtures were in the hyper-additivity area (σ > 1.05), and two were in the so-called perfect additivity area (0.95 < σ < 1.05). Almost one half (48%) showed compromise level. Finally, a significantly difference was observed by flash gas chromatography electronic nose (p < .05). Sensory analysis revealed that a mask effect of fruity note was occurred by adding ethyl phenylacetate at various levels (100, 2500, 58,000 ppb) to the fruit recombination and an enhancement effect of floral note was reported by adding phenylethyl acetate at low (1400 ppb) or high level (11,500 ppb). It was noticed that sweet note was significantly enhanced by adding phenylethyl acetate at peri-threshold (3200 ppb).