Assesing temporal changes in sweetness and other flavor descriptors during tasting of water or yogurt with added sweeteners using the progressive profile method

International audienceThis study aimed to adapt a method to compare the temporal evolution of sweet taste intensity, as a main descriptor of interest, in water or yoghurt sweetened with different sweeteners. Other descriptors related to off-tastes (bitterness, metallic, liquorice, acid) were followed as well as a mouthfeel descriptor (mouth coating). To achieve this goal, we adapted the progressive profile [1], or sequential profiling [2], method to record alternatively sweetness or a profile of the selected descriptors at various times of the tasting process [3]. A trained sensory panel of 30 volunteers had to taste sweetened Evian water over several sips or sweetened fat-free yoghurt over several spoonfuls. Two types of sweeteners were compared: a bulk sweetener (sucrose), and a natural intensive sweetener (Rebaudioside A). In the adapted progressive profile, sweet taste intensity was rated on an anchored linear scale at different times of consumption (T0, T10sec, T20sec, T35sec, T45sec, T55sec), while bitterness, metallic, liquorice, acid, and mouth coating attributes were rated after deglutination (T20sec) and at the end of the evaluation (T55sec). This sequence was repeated 4 times in a row over 4 sips (water) or 4 spoonfuls (yoghurt). As a main result, we observed that in both water and yoghurt, sweetness decreased more quickly within and across sips/spoonfuls for sucrose compared to Rebaudioside A. Moreover, the perception of the metallic and bitter off-taste were reduced whatever the sweetner added. When the bitter and/or liquorice off-taste were detected, their intensities were higher at the swallowing time. Finally, no taste potentiation was observed along the 4 sips/spoonfuls. In conclusion, the present adaptation of the progressive profile appears as an interesting temporal method that allows monitoring, with a trained panel, of the changes in the intensity of target descriptors within different food matrices