Food acceptability for the consumer is mainly driven by organoleptic properties and among them flavor perception. Flavor can be defined as a multisensory perception involving olfactory, gustatory, and trigeminal sensations during food consumption. Flavor perception results from the integration at the central level of olfactory, gustatory, and trigeminal information from the chemical compounds present in the food (Thomas-Danguin, 2009). Thus, flavor perception is due to a wide range of stimuli: odorant compounds which activate the olfactory receptors, taste compounds which activate the gustatory receptors, and trigeminal compounds which activate the trigeminal nerve. In this chapter, we will only focus on the retention/release mechanisms of odorant/aroma compounds as a function of food composition. Aroma compounds activate olfactory receptors, via the orthonasal route, by smelling the food before consumption, and via the retronasal route during the in-mouth process (Figure 29.1). Transfer of aroma compounds from the food to the olfactory receptors during food consumption. https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429441837/be9ed440-316b-431a-a515-a29a5f2c371e/content/fig29_1_B.tif"/>