# Flavor Chemistry of Virgin Olive Oil: An Overview
## 2 VOO Flavor Perception
The results of the fMRI obtained showed different hedonistic values of the olfactory perception of a related oil in relation to its quality and therefore its pleasure for every single individual (Figure 2). The zones with the highest activity were the orbitofrontal, the frontal and the temporal lobes which correspond to Brodmann areas 6, 10, 11, 20 and 47. The bilateral activations BA 10, 11 and 47 were associated to the olfactory process which explains their activation in response to both pleasant and unpleasant samples. An increase in cerebral blood flow in  
Figure 1: Schematic diagram representing virgin olive oil flavor perception. Legend: (1) extra virgin olive oil glass, (2) odor (through ortho-nasal route), (3) aroma (through retro-nasal route), (4) nasal cavity, (5) olfactory bulb, (6) olfactory epithelium (sense of smell), (7) tongue (sense of taste), (8) taste buds (bitterness perception), (9) oral cavity, (10) trigeminal nerve (chemesthesis perception: pungency), and (11) signal in the brain and the recognition of sensory perception (adapted from [PERSON] and [PERSON] [29]). the BA 11 is also associated with the familiarity of odors, which would explain the high activation area seen in subjects who were regular users of virgin olive oils. Details of the application of functional magnetic resonance imaging (fMRI) and the aspects related to experimental design, data acquisition and data processing are described in [PERSON] and coauthors [32]. One can hypothesize that some olive oil odorants might be able to mislead the brain. It can also be hypothesized that the \"green\" flavor of VOO exerts a positive effect on the food intake and satiation. In fact, German scientists reported that yogurt containing an aromatic extract of VOO modulates the cerebral blood in frontal operculum, inducing brain activation more similar to that induced by the high-fat yogurt [33]. Using a fat-free yogurt, two groups of assessors tasted a product added with an olive oil aroma extract in comparison to a control product. The group who ate the plain yogurt showed a drop in serotonin levels a hormone associated with satiety. Thus, this group reported less satiation after eating it. They also did not cut back on other calories to compensate; instead, their intake increased an average of 176 calories a day. On the contrary, the group eating the olive-oil flavored yogurt reduced their calories from other foods and showed better responses when given glucose tolerance tests, which measures the blood sugar control. Abrupt swings in blood sugar are part of what drives hunger and satiety. The sense of gratification and/or reward linked to VOO intake might be attributed to the herbaceous odor of molecules such as hexanal, _trans_-2-hexanal, and _cis_-3-hexanol. These molecules are the most abundant volatiles in VOO, and previous research has shown that they are able to stimulate the release of dopamine in the brain [34]. This was also confirmed by the study by [PERSON] and coauthors [35], which verified an increase in the release of dopamine in the presence of herbaceous odors such as that of hexanal, explaining that this molecule could induce an increase in the intracellular concentration of Ca\({}^{2+}\) and the dephosphorylation of phosphorylated proteins, phenomena required for a greater release of dopamine. The herbaceous smell of VOO, therefore, could influence and regulate the stimulation of dopamine release and thus increase the sense of gratification of the food consumed.