Characterizing consumer emotional response to sweeteners using an emotion terminology questionnaire and facial expression analysis

• Honey and acesulfame K were not as acceptable as sucrose in black tea.
• Honey elicited selection of the emotional term disgust when used as a sweetener in black tea.
• Sweetener acceptability is decreased when emotions mild, bored and disgusted are selected.
• Differences in time sequence of implicit emotions for each sweetener are evident.
• Using explicit and implicit emotions together enhances understanding of sweetener acceptability.

Concerns associated with sugar-sweetened beverages (SSBs) have led to an increased consumer demand for sweetener alternatives that are functionally (and taste) equivalent to sucrose without the associated health risks. Measuring consumer emotions has the potential to aid the industry in subsequent ingredient decision-making. The purpose of this study was to evaluate the relationship of consumer acceptability and emotional response of sweeteners in tea using a 9-point hedonic scale, an emotion term questionnaire (explicit), and a facial expression response (implicit).Participants (n = 30) evaluated a water sample (baseline), two (5%) sucrose-tea samples (control), and four equi-sweet alternative sweetener-tea samples (ace-k, sucralose, high fructose corn syrup and honey), divided by category (artificial; natural). Sessions (4 total, spread over 2 days) were divided by category and emotional response tool in a cross-over design. Facial expression responses were recorded in the first session of both days using FaceReader 5.0 and individual participant videos were analyzed per sample for 5-s post-consumption (α = 0.05) in the continuous analysis setting using automated facial expression analysis software. Emotional term responses were collected in the second session of each day and count frequencies of each term per sample were tabulated and analyzed. Hedonic acceptability was rated in all sessions on a 9-point scale.Alternative sweeteners were all rated ‘acceptable’ (score of 5 or higher), except for honey in one session. Only one alternative in each category was statistically different (p < 0.05) in liking from sucrose. Facial analysis showed minimal differences in emotion elicited across sweetener categories. Time series analysis was more robust in showing differences (p < 0.05) than baseline comparisons. Emotional term selection using a CATA questionnaire showed four unique terms (disgusted, good, mild, steady) for natural sweeteners and two unique terms (bored, good-natured) for artificial sweeteners. More research exploration related to emotions and food is needed in order to accrue a more accurate picture of consumer product preferences.