ABSTRACT High sugar intake and exposure to negative mood states are known to influence food‐related decisions; however, the specific effects of short‐term mental fatigue on sensory perception and label evaluation remain unclear. This study investigated the impact of experimentally induced mental fatigue on hedonic responses, ideal sweetness perception, and front‐of‐package label evaluation of passion fruit juice with different sugar contents. One hundred healthy adults (18–60 years) participated in a randomized crossover design, evaluating juice samples (0%, 5%, 10%, 15%, and 20% sucrose) and three label formats under control and Stroop test–induced mental fatigue condition (SMF). Mood alterations were confirmed using the Profile of Mood States (POMS), showing increased tension ( p = 0.013) and confusion ( p = 0.054) and reduced vigor ( p = 0.030) under SMF, leading to a moderate overall mood disturbance ( d = 0.320). Despite the mood changes caused by the SMF, hedonic tests revealed no significant differences between fatigue and control conditions for overall acceptance or ideal sweetness perception; in both conditions, the 10% sucrose sample was rated closest to the ideal and showed the highest acceptance. Similarly, purchase intention did not differ between groups for any label. However, within‐group comparisons indicated that labels without a high‐sugar warning elicited higher purchase intention than those displaying a warning seal, regardless of fatigue state. Analysis of open‐ended responses demonstrated that SMF reduced attention to peripheral visual elements, such as design and brand identification, while attention to critical nutritional information (e.g., sugar content and nutrition facts) remained unchanged. These findings suggest that SMF alters mood but does not significantly impair hedonic judgments or sweetness perception, while selectively narrowing attentional focus during label evaluation.
Bresciani et al. (2026) studied this question.