Preparation and sensory perception of fat-free foams : Effect of matrix properties and level of aeration

The sensory perception of fat-free model foams with a consistency between pourable (liquid; xanthan thickened) and spoonable (semi-solid; gelled; carrageenan thickened) and varying level of aeration was studied. At low air contents (5, 10% v/v) perception is largely determined by the matrix properties; the presence of air is hardly experienced. On the other hand, at high levels of aeration (80% v/v) perception is determined by bubble characteristics and the matrix plays a negligible role in perception. Bubbles were better noticeable in a semi-solid, i.e. carrageenan matrix, than in liquid, i.e. xanthan-based foams. In semi-solid sucrose¿ester carrageenan foams, large bubbles were perceived as more airy and less creamy, compared with the same compositions with smaller bubbles.