Flavour release at gas/matrix interfaces of stirred yoghurt models

Release of strawberry flavour compounds at vapour/matrix interfaces was studied in model food systems simulating a yoghurt with a fruit preparation syrup. The effect of different parameters including physicochemical characteristics of the flavour compound, the structure and composition of the matrix and the temperature (4 and 10°C) on the release of the flavour compounds were investigated. There was an effect of the composition and structure of the matrix upon the partition of the flavour compounds. In the dairy gel, retention of flavour compounds was caused by the physicochemical interactions with the proteins and the solubilisation in dispersed fat. The addition of syrup to the low-fat dairy gel slightly increased the retention of the flavour compounds; this was attributed to physicochemical interactions with pectin and sucrose. In the presence of fat (5%), the flavour compounds were solubilised in the fat and their release was not affected by the composition of the dispersing medium. As expected, temperature affected the release; an increase from 4 to 10 °C resulted in an increase in the overall amount of flavour released.