Results from the present work showed that sugar reduction in probiotic chocolate-flavored milk mainly influenced sweetness, bitterness and thickness. A reduction in added sugar of 20% led to changes in sweetness perception, which was perceived by both trained assessors and consumers. However, consumers' liking was not largely affected by sugar reductions up to 40%, suggesting that the sugar content of chocolate-flavored milks in the Uruguayan marketplace is probably excessive and could be decreased without a relevant impact on consumers' sensory and hedonic responses. Further research aiming at determining difference thresholds in sweet taste could contribute to the development of strategies for gradual sugar reduction in processed products.
The addition of artificial vanilla flavor at suprathreshold concentrations was not efficient in increasing sweetness perception in chocolate-flavored milks with the lowest sugar reduction percentage, suggesting that it may not be a feasible alternative for reducing sugar in this product category. Regarding thaumatin, it did not influence sweetness perception when added in a concentration up to 10 ppm in products with low sugar reduction. Further research exploring the influence of higher concentrations of thaumatin in sweetness perception of chocolate-flavored milks and other dairy products seems necessary.
From a methodological point of view, it is worth highlighting that TCATA, a novel temporal methodology, enabled to gather information about the dynamics of the perception of the sensory characteristics of chocolate-flavored milks with trained assessors and consumers. Results provided by both groups of assessors were similar and enabled to identify differences among samples.