Publication Tag: Food Science

Traditional sensory and hedonic tests are often limited to predict market performance. Investigating emotional responses to food stimuli may contribute to a better understanding of consumers’ eating behavior. In the present study, 26 female participants were exposed to an orange (pleasant) and a fish (unpleasant) odor presented in three different concentrations perceived as weak, medium and strong intensity in a semi-random order via an olfactometer. Emotional responses to those food odors were measured discretely using non-verbal subjective reports, and continuously using facial expressions. Non-verbal reports reflected primarily the odor’s valence with positive emotions, such as joy, satisfaction and hope, related to orange and negative emotions, such as dissatisfaction, fear and disgust, related to fish. Facial expressions varied dynamically over the 4 s following stimulation, whereby expressions at 1250 and 2000 ms associated best with odor valence and odor intensity, respectively. The correlation between non-verbal subjective reports and facial expressions reached a maximum during the second sec after exposure. Pleasant odors were associated with neutral and surprised expressions, and with fewer expressions of disgust. More intense odors were associated with fewer neutral expressions and more expressions of disgust. Facial expressions reflect the dynamic sequential unfolding of different emotional responses, whereas non-verbal reports primarily reflect the end result of valence appraisal. The distinction between initial and subsequent reactions detected by facial expressions may offer a new valuable perspective for sensory and consumer research.

Differences in food consumption among individuals with varying body mass indexes have raised questions about why overweight individuals or those at risk of becoming overweight eat differently from thinner individuals. One explanation suggests that sensitivity to the affective properties of food, particularly palatability-driven consumption, significantly contributes to food intake and, consequently, body weight. Extending this approach to unpalatable tastes, this study examined the relationship between aversive reactions to bitter-tasting foods and BMI. It was hypothesized that individuals with a high BMI would exhibit more negative affective reactions to bitter stimuli, even after controlling for sensory perception differences. Given that hedonic reactions may influence consumption without conscious feelings of pleasure or displeasure, facial expressions were analyzed to provide more direct access to affective responses than subjective reports. Forty adults aged 18 to 46 years participated voluntarily. Participants were classified based on BMI into low BMI and high BMI groups. The mean BMI was 19.1 for the low BMI group and 25.2 for the high BMI group . Each subject tasted 5 mL of a grapefruit juice drink and a bitter chocolate drink. Subjects rated the drinks’ hedonic and incentive value, familiarity, and bitter intensity immediately after each stimulus presentation. The results indicated that high BMI participants exhibited more profound changes from baseline in neutral and disgust facial expressions in response to bitter stimuli compared with low BMI participants. No differences between groups were detected for subjective pleasantness and familiarity. This research is the first to examine how affective facial reactions to bitter food, apart from taste responsiveness, can predict differences in BMI.

Traditional sensory and consumer tests predict long term consumer acceptance of new products rather poorly, as evidenced by the high failure rates of new market introductions. These tests typical reflect conscious processes whereas consumer acceptance may also be based on unconscious processes, which may be measured by implicit physiological and behavioral measures. This study with 16 children (aged 8–10 years) and 15 young adults (mean age 22 years) explored the use of selected physiological and behavioral measures of the autonomic nervous system (ANS) in the study of foods. Three liked and three disliked foods were selected for each participant and their responses were measured during the first sight of each food and when they received the instruction to either visually inspect, smell or taste the foods. The first sight of disliked foods compared to liked foods resulted in increased skin conductance responses (p = 0.05) and increased facial expressions of sadness, disgust, and angriness (p = 0.05). Skin conductance responses (SCRs) varied significantly with the type of instruction (p < 0.001), with relatively small SCRs when participants were instructed to visually inspect the foods and larger SCRs when they are instructed to taste or smell the foods. When instructed to taste the foods, children showed increased SCRs for disliked foods while young adults showed decreased SCRs (p = 0.02). Heart rate varied with instruction and age group (p = 0.03). Children showed increased heart rate when instructed to visual inspect or taste the foods and reduced heart rate they were instructed to smell them. In contrast, young adults showed reduced heart rate when instructed to visual inspect and increased heart rate with instructed to taste or smell. Finger temperature was higher for liked foods than for disliked foods, irrespective of instruction and age group (p < 0.01). It is concluded that implicit ANS and behavioral responses provide detailed information on food preferences in relation to specific food properties and phases of food sampling that may not be provided by other more explicit tests.