Perception of sweet-sour mixtures in water and wine. Contextual effects.

ZAMORA, M. C.; GOLDNER, M. C.; GUIRAO, M.

Portugal

Congreso; Twentyth Annual Meeting of the International Society for Psychophysics; 2004

The  effect of context on sweet and sour  mixtures tasted in water and in white wine samples was evaluated. Three concentrations of fructose mixed with tartaric acid adjusted to three pH levels were used. Ten trained assessors participated in the experiments. A full factorial design gave   nine samples for each one of the two media.  Analyses of variance for sweetness showed that tartaric acid and fructose effects were significant at the 0.1%  level and only the  interaction context*pH (tartaric acid) was significant at the 5% level. For sourness, tartaric acid and fructose effects and its interactions context*fructose*pH and context*pH were significant at the 0.1% level, which indicate that sourness perception is notably affected by  context.  Interactions of taste mixtures were similar in the two media. The  suppressive effect of sourness of tartaric acid over sweetness of  fructose   was stronger at the low and median concentration levels.  At  the highest level of fructose sweetness suppressed sourness. These effects were more drastic in the water than in the wine context. The sour/sweet balance is represented in two functions. The wine shows a notable reduction in the range of sourness.