Bitterness enhancement induced by cut grass odorant (cis-3-hexen-1-ol) in a model olive oil

In the present study the taste-smell interaction between bitterness and cut grass odour was studied in a model olive oil. Investigating the extent to which the green aroma affects the perception of bitterness in virgin olive oil may affect the identification of new strategies for optimising the sensory properties of the product. The study was organised in four stages: a pre-testing stage verified the suitability of the tastant (quinine dihydrochloride) and the odorant ( cis -3-hexen-1-ol) and to select a moderate concentration of the cut grass odour and a spread of different concentrations of the bitter compound ranging from weak to strong. A second stage studied the effect of the cut grass odour on the intensity of bitterness perceived in the oil and on the oil's pleasantness (experiment 1). A third stage studied the influence of the cut grass odour on the dynamic process of the perception of bitterness (experiment 2). A fourth stage, to stimulate a nose-occlusion control condition, verified the sensory nature of the interaction between the odorant and tastant (experiment 3). The results show that the green odour note has a positive significant effect on the perception of bitterness. The presence of cut grass odour enhances the bitterness perception. New strategies in controlling the perceived intensity of bitterness in virgin olive oil may be defined.