Influence of flavour transfer between different gel phases on perceived aroma

Multiphasic models of stirred fruit yoghurts made from a bilayer that consisted of a pectin and a dairy gel were developed in order to study the transfer of strawberry flavour compounds between the two phases. Several parameters (i.e., the flavour concentration, the fat content of the dairy gel and the storage temperature) affecting flavour compound transfer, using an experimental design, together with their effect on sensory perception were investigated. Strawberry flavour transfer between the two gels was high enough to affect the sensory perception of the dairy gels. The parameters that modified the partitioning of ethyl esters between the pectin and dairy gel (i.e., fat content of the dairy gel and flavour concentration) also affected the perception of the fruity odour attribute; the storage temperature had no effect on the sensory perception. An increase in the initial flavour concentration in the pectin gel increased the fruity odour intensity of both gels. Conversely, the presence of fat in the dairy gel decreased the odour intensity of both gels by reducing flavour compound volatility in the dairy gel and decreasing the flavour concentration in the pectin gel.