Temporal dominance of emotions: Measuring dynamics of food-related emotions during consumption

Multi-attribute temporal descriptive methods in sensory analysis applied in food science: A systematic scoping review

Among descriptive sensory evaluation methods, temporal methods have a wide audience in food science because they make it possible to follow perception as close as possible to the moment when sensations are perceived. The aim of this work was to describe 30 years of research involving temporal methods by mapping the scientific literature using a systematic scoping review. Thus, 363 research articles found from a search in Scopus and Web of Science from 1991 to 2022 were included. The extracted data included information on the implementation of studies referring to the use of temporal methods (details related to subjects, products, descriptors, research design, data analysis, etc.), reasons why they were used and the conclusions they allowed to be drawn. Metadata analysis and critical appraisal were also carried out. A quantitative and qualitative synthesis of the results allowed the identification of trends in the way in which the methods were developed, refined, and disseminated. Overall, a large heterogeneity was noted in the way in which the temporal measurements were carried out and the results presented. Some critical research gaps in establishing the validity and reliability of temporal methods have also been identified. They were mostly related to the details of implementation of the methods (e.g., almost no justification for the number of consumers included in the studies, absence of report on panel repeatability) and data analysis (e.g., prevalence of use of exploratory data analysis, only 20% of studies using confirmatory analyses considering the dynamic nature of the data). These results suggest the need for general guidelines on how to implement the method, analyze and interpret data, and report the results. Thus, a template and checklist for reporting data and results were proposed to help increase the quality of future research.

Sensory and affective response to chocolate differing in cocoa content: A TDS and facial electromyography approach

Existing research has offered insight into facial activities and their associations with hedonic liking during the consumption of basic food samples and suggests facial changes during consumption are linked to the hedonic evaluation of tastes and, thus related to the taster's perception rather than the tastes themselves. This study tests whether, during the consumption of commercially available dark chocolate, a complex food product, which can be high in bitterness but expectedly so, how facial activities are linked to the bitterness levels and the hedonic liking of the samples. To do this we carried out two studies with untrained consumers, the first of which captured temporally dynamic sensory perception during the consumption of dark chocolate samples of 36% and 85% cocoa content, using the Temporal Dominance of Sensations (TDS) approach. The second study captured facial EMG over the corrugator and zygomaticus muscles during the consumption of dark chocolate samples (36%, 70%, and 85% cocoa). Specifically, the aim of this research was to investigate whether corrugator activity had a greater association with bitterness perception, linked to cocoa, or hedonic evaluation. Capturing the dynamic sensory profile of chocolate samples allowed an investigation into the time points most evident of sensory variation related to the bitterness and sweetness of the taste, allowing insight into whether facial activities also deviated during this time. These data offer evidence to suggest that corrugator was associated with hedonic evaluation during consumption of the samples, with the most liked samples (being those with 70% and 36% cocoa) eliciting similar corrugator activities and less activity than the least liked 85% cocoa content sample; however, there was also evidence to suggest a significant variation in participants' corrugator activity during the period of oral processing when bitterness was most evident in the 85% cocoa sample and sweetness was most evident in the 36% cocoa sample (i.e., the time when bitterness and sweetness were most divergent) Further investigation showed a variation in facial activities elicited during consumption of the 36% cocoa sample based on whether individuals were part of the group who favoured the 85% cocoa sample or the group favouring the 36% cocoa sample. The findings, therefore, suggest facial EMG, specifically over the corrugator, appears to be related to the hedonic evaluation of a complex food product and not the taste itself. Furthermore, being aware of the time points where sensory variations are most apparent between samples can allow for targeted investigation into facial EMG and its ability to distinguish food samples.

Comparing consumer liking of beef from three feeding systems using a combination of traditional and temporal liking sensory methods

Research on the effects of animal diet on consumer liking of beef has yielded conflicting results. Currently it is unknown whether dynamic changes occur in liking during consumption of beef. This study applied a combination of traditional and temporal (free and structured) liking methods to determine consumer liking of beef derived from animals that were fed grain (GF), grass silage plus grain (SG) or grazed grass (GG) during finishing. Three separate panels of beef eating consumers (n = 51; n = 52; n = 50) were recruited from Teagasc Food Research Centre, Dublin, Ireland to assess striploin steaks from animals fed either GF, SG, or GG. Using the free temporal liking (TL) method, results revealed that beef from GF animals was liked significantly less (p ≤ 0.05) in terms of overall liking, tenderness and juiciness, when compared to steaks from the SG and GG animals. These effects were not observed using the structured TL or traditional liking methods. Further analysis showed the evolution of scores over time was significant (p ≤ 0.05) for all attributes using the free TL method. Overall, the free TL method yielded more discriminative data and was perceived as easier to perform by consumers compared to the structured TL method. These results show that the free TL method may provide an opportunity to elicit more in-depth information regarding consumer sensory response to meat.

A Timely Application-Temporal methods, past, present, and future

Eating is a dynamic experience, and temporal sensory methods have been proposed to document how products change over the course of consumption or use (nonfood). A search of online databases yielded approximately 170 sources related to temporal evaluation of food products that were compiled and reviewed. This review summarizes the evolution of temporal methodologies (past), offers guidance in selecting appropriate methods (present), and provides insights into the future of temporal methodologies in the sensory space. Temporal methods have evolved to document a variety of characteristics in food products including how the intensity of a specific attribute changes over time (Time-Intensity), which specific attribute is dominant at each time during evaluation (Temporal Dominance of Sensations), which attributes are present at each time point during evaluation (Temporal Check-All-That-Apply), and many others (Temporal Order of Sensations, Attack-Evolution-Finish, and Temporal Ranking). In addition to documenting the evolution of temporal methods, this review considers the selection of an appropriate temporal method based on the objective and scope of research. When choosing a temporal method, researchers should also consider the selection of panelists to perform the temporal evaluation. Future temporal research should focus on validation of new temporal methods and explore how methods can be implemented and improved to add to the usefulness of temporal techniques for researchers.

Musical and Non-Musical Sounds Influence the Flavour Perception of Chocolate Ice Cream and Emotional Responses

Auditory cues, such as real-world sounds or music, influence how we perceive food. The main aim of the present study was to investigate the influence of negatively and positively valenced mixtures of musical and non-musical sounds on the affective states of participants and their perception of chocolate ice cream. Consuming ice cream while listening to liked music (LM) and while listening to the combination of liked music and pleasant sound (LMPS) conditions gave rise to more positive emotions than listening to just pleasant sound (PS). Consuming ice cream during the LM condition resulted in the longest duration of perceived sweetness. On the other hand, PS and LMPS conditions resulted in cocoa dominating for longer. Bitterness and roasted were dominant under the disliked music and unpleasant sound (DMUS) and DM conditions respectively. Positive emotions correlated well with the temporal sensory perception of sweetness and cocoa when consuming chocolate ice cream under the positively valenced auditory conditions. In contrast, negative emotions were associated with bitter and roasted tastes/flavours under the negatively valenced auditory conditions. The combination of pleasant music and non-musical sound conditions evoked more positive emotions than when either was presented in isolation. Taken together, the results of this study support the view that sensory attributes correlated well with emotions evoked when consuming ice cream under different auditory conditions varying in terms of their valence.

Changes in temporal sensory profile, liking, satiety, and postconsumption attributes of yogurt with natural sweeteners

Abstract

Sweetened yogurts can contain between 10 and 13% added sugar. However, studies have shown that sugar reduction or replacement can influence yogurt quality. The main objective of this research was to investigate the effects of yogurt with added natural sweeteners on temporal sensory profile, liking, satiety and postconsumption measures. Yogurt samples were prepared with iso‐sweet concentrations of sucrose (9 g/100 g of plain yogurt) using xylitol (10 g/100 g), stevia (0.15 g/100 g), and monk fruit (0.15 g/100 g). Fifty panelists evaluated the temporal sensory profile of these yogurts using multiple‐intake temporal dominance of sensations (TDS), and overall liking for each intake. In addition, satiety (hunger, thirst, and fullness) and other postconsumption attributes (healthiness, satisfaction, and purchase intent) were determined. The temporal profile of yogurt sweetened with xylitol was similar to yogurt sweetened with sucrose without any onset of negative sensory characteristics at any point in intake. Yogurt sweetened with stevia had a high dominance duration for astringency. Moreover, yogurt sweetened with monk fruit showed increased dominance of attributes bitter and astringent from the first to third intake. In terms of liking, yogurt containing xylitol was scored the highest followed by stevia and monkfruit. Sweet was a positive temporal driver of liking in yogurt sweetened with monk fruit. However, mouthcoating, sweet, and sour decreased liking in yogurt sweetened with sucrose, xylitol, and stevia respectively. In terms of perceived healthiness, satisfaction and purchase intent, yogurt sweetened with sucrose scored the highest followed by xylitol. Consumption of yogurt sweetened with xylitol, stevia, or monk fruit significantly decreased hunger compared to yogurt sweetened with sucrose.

Practical Application

The current findings will play an important role for the dairy industry in understanding how sugar replacement with natural sweeteners in yogurt can influence its sensory perception and postconsumption behavior.

Linking Temporal Dominance of Sensations for Primary-Sensory and Multi-Sensory Attributes Using Canonical Correlation Analysis

Sensory responses dynamically change while eating foods. Temporal dominance of sensations (TDS) methods record temporal evolution and have attracted attention in the last decade. ISO 13299 recommends that different levels of attributes are investigated in separate TDS trials. However, only a few studies have attempted to link the dynamics of two different levels of sensory attributes. We propose a method to link the concurrent values of dominance proportions for primary- and multi-sensory attributes using canonical correlation analysis. First, panels categorized several attributes into primary- and multi-sensory attributes. Primary-sensory attributes included sweet, sour, fruity, green, watery, juicy, aromatic, and light. Multi-sensory attributes included refreshing, fresh, pleasurable, rich/deep, ripe, and mild. We applied the TDS methods to strawberries using these two categories of attributes. The obtained canonical correlation model reasonably represented the relationship between the sensations in a reductive manner using five latent variables. The latent variables couple multiple primary- and multi-sensory responses that covary. Hence, the latent variables suggest key components to comprehend food intake experiences. We further compared the model based on the dominance proportions and the time-derivatives of the dominance proportions. We found that the former model was better in terms of the ease of interpreting the canonical variables and the degree to which the canonical variables explain the dominance proportions. Thus, these models help understand and leverage the sensory values of food products.

An Overview of Sensory Characterization Techniques: From Classical Descriptive Analysis to the Emergence of Novel Profiling Methods

Sensory science provides objective information about the consumer understanding of a product, the acceptance or rejection of stimuli, and the description of the emotions evoked. It is possible to answer how consumers perceive a product through discriminative and descriptive techniques. However, perception can change over time, and these fluctuations can be measured with time-intensity methods. Instrumental sensory devices and immersive techniques are gaining headway as sensory profiling techniques. The authors of this paper critically review sensory techniques from classical descriptive analysis to the emergence of novel profiling methods. Though research has been done in the creation of new sensory methods and comparison of those methods, little attention has been given to the timeline approach and its advantages and challenges. This study aimed to gather, explain, simplify, and discuss the evolution of sensory techniques.

Sensory Drivers of Consumer Acceptance, Purchase Intent and Emotions toward Brewed Black Coffee

The link between coffee aroma/flavor and elicited emotions remains underexplored. This research identified key sensory characteristics of brewed black coffee that affected acceptance, purchase intent and emotions for Thai consumers. Eight Arabica coffee samples were evaluated by eight trained descriptive panelists for intensities of 26 sensory attributes and by 100 brewed black coffee users for acceptance, purchase intent and emotions. Results showed that the samples exhibited a wide range of sensory characteristics, and large differences were mainly described by the attributes coffee identity (coffee ID), roasted, bitter taste, balance/blended and fullness. Differences also existed among the samples for overall liking, purchase intent and most emotion terms. Partial least square regression analysis revealed that liking, purchase intent and positive emotions, such as active, alert, awake, energetic, enthusiastic, feel good, happy, jump start, impressed, pleased, refreshed and vigorous were driven by coffee ID, roasted, ashy, pipe tobacco, bitter taste, rubber, overall sweet, balanced/blended, fullness and longevity. Contrarily, sour aromatic, sour taste, fruity, woody, musty/earthy, musty/dusty and molasses decreased liking, purchase intent and positive emotions, and stimulated negative emotions, such as disappointed, grouchy and unfulfilled. This information could be useful for creating or modifying the sensory profile of brewed black coffee to increase consumer acceptance.

Which Factors Drive Consumer Decisions during Milk Purchase? New Individuals' Profiles Considering Fresh Pasteurized and UHT Treated Milk

The cow’s milk market is going through a critical period characterised by a continuous contraction in consumption as a consequence of the lack of competitiveness on the market of the conventional product (commodity) versus numerous specialties. This paper aimed to define the profiles of milk consumers in terms of individual preferences (assessed using the best-worst scaling methodology) and socio-demographic features. A survey was conducted in several stores of large-scale retail, convenience stores, and open-air markets distributed in north-west Italy to collect data from 1216 respondents. For milk shopper purchasing habits, two consumer groups were defined and compared in terms of preferences: the fresh pasteurized milk consumer (FPc) (56% of the total sample) and the ultra-high temperature treated milk consumer (UHT_c) (35%). A series of two-ways multivariate analysis of variance (MANOVA) were conducted to assess the effect of individuals’ socio-demographic characteristics and the type of milk chosen on the consumer preferences, simultaneously. Significant differences in milk purchasing habits and preferences emerged when comparing the two consumer groups (UHT_c and FP_c). Empirical evidence of the study supported the starting hypothesis, suggesting the significance or relevance of the consumer socio-demographic characteristic, as well as their interaction effect with the type of milk on the level of importance given to the considered milk quality attributes. On the contrary, the gender results were not significant for the milk preferences definition. The assessment of consumer preferences, associated with the individuals’ socio-demographic characteristics could have important implications for outlining more effective marketing strategies based on a more targeted communication (i.e., related to the sustainability dimension of the local product, nutritional value and brand), leading the consumer back to the commodity rediscovery concerning individuals’ features and habits.

Impact of music on the dynamic perception of coffee and evoked emotions evaluated by temporal dominance of sensations (TDS) and emotions (TDE)

The aim of the present work was to study the temporal effect of music on sensory perception and on the emotional changes while drinking coffee. Two different commercial filter coffees were evaluated by a group of 48 consumers using the Temporal Dominance of Sensations (TDS) method. The description was performed in silence and also while listening to two different musical fragments: one with a "sweet" connotation and the other with a "bitter" one. Under the same conditions (drinking coffee with and without musical stimuli), a different group of 72 consumers evaluated their perceived emotions (joy, fear, neutral, rejection, disgust, surprise, sadness and anger) by Temporal Dominance of Emotions (TDE). Data was analyzed by dominance curves and by ANOVA and MANOVA of the durations of dominance (for emotions and sensations). Coffee perception, in both cases, was modified by the musical stimuli. The duration of dominance of bitter was increased in the presence of "bitter" music, while it decreased with the "sweet" music. Moreover, the sweet attribute was practically not chosen for describing the coffee on its own, but its choice and duration as dominant increased while listening to the "sweet" musical fragment. Music had a larger impact on the perceived emotions. The "sweet" music was related to the emotion of joy, which was accompanied by surprise and also some sadness when drinking coffee (regardless of the type of coffee being drunk). The "bitter" music was linked to the emotions anger and fear. The effect of "sonic seasoning" and translation of emotions with a familiar product was observed.

Challenges of pairing chocolates and nuts: Perceptions, interactions and dynamics of contrasting chocolates with nuts

Chocolates paired with nuts are highly marketed products, however, there is a lack of scientific research and limited understanding of consumer sentiment towards the combination of these food products. The main objective of this research was to determine the consumers' response towards pairing five different chocolates (dark origin, milk, Gold, white fruity, and white vanilla) and three different nuts (hazelnut, almond, and pistachio) for the creation of pairing guidelines within Barry Callebaut's range. TimeSens© software was applied to assess the dynamic interaction of flavors through temporal dominance of sensations (TDS). It was observed that each type of chocolate presents different interactions of dominant flavors depending on the nut and its applications. Furthermore, variables such as liking, balance, and check-all-that-apply (CATA) were analyzed to create pairing guidelines related to different responses on the predominant flavor of each of the chocolates. These case studies determined that the liking of the different pairs was influenced by the dominant flavors of each of the chocolates and the balance found in the match. From the predominant flavors, it was concluded that respondents preferred chocolates with sweet and dairy attributes such as: milky, creamy, buttery. Salty and vanilla flavors also made good pairs as they accentuate the nut flavor. On the contrary, chocolates with intense bitter, roasted, cocoa, and sour flavors did not create the best combinations with the nuts, as these are contrasting or strong flavors that consumers are usually unfamiliar with when combined with nuts. To complement this study, further analysis can be developed using other types of chocolates, nuts, and applications, and then comparing the dominant flavors of the chocolates with distinctive nuts to assess the consumers' response towards the combinations.

Designing a Low-Fat Food Packaging: Comparing Consumers' Responses in Virtual and Physical Shopping Environments

This paper aims to test to what extent emotional responses towards a low-fat product presented virtually converge with emotional responses toward this product when presented physically. Second, we want to probe if low-order emotions (physiological/unconscious responses) and high-order emotions (cognitive/conscious responses) converge to explain healthy product choices. To this end, 83 young participants were engaged in our experiment. Two packaging design variables were manipulated with the help of a real company (the color and the message), so that six different packages were created. Two different buying contexts were simulated: A virtual context and a physical context. Physiological responses were continuously recorded in both contexts (heart rates, electro-dermal responses, and eye muscle reactions). At the end, participants provided cognitive responses in a questionnaire concerning the selected package. Our results have demonstrated that low-order emotions remain stable (from a virtual to a physical environments). Virtual simulations elections and real product elections are correlated (X² = 40.493; p < 0.02). Physiological and cognitive responses do not converge. Correlations between unconscious responses (low-order emotions) and self-reported measures (high-order emotions) was contrary to expectations (negative sign). Only low-order emotions explain product choices. On the contrary, real packaging choice and high-order emotions correlated inversely (the t values were significant but negative).

Sensory and Physicochemical Characterization of Sourdough Bread Prepared with a Coconut Water Kefir Starter

There is a recognized need for formulating functional food products using selected lactic acid bacteria (LAB) starter cultures from various sources such as kefir, yoghurt or kombucha that have health benefits. The principle objective of this study was to investigate the use of a coconut water kefir-based fermentation starter culture using Lactobacillus fermentum and Lactobacillus plantarum to develop a sourdough bread. Check-all-that-apply (CATA) sensory profiling was used in this study to evaluate the sensory profile of sourdough breads that varied with culture type, culture concentrations, with and without added yeast, and with fermentation for 18 and 24 h. Based on correspondence analysis (CA) of the CATA results, bread samples with positive sensory attributes were chosen for further physicochemical analysis. Physicochemical analyses (texture, proximate composition, shelf life, carboxylic acid analysis and amino acid analysis) were carried out on breads formulated with starter culture concentrations of 8.30 log CFU/mL of L. fermentum, 4.90 log CFU/mL of L. fermentum and 9.60 log CFU/mL of L. plantarum, each fermented for 24 h without baker's yeast. The bread sample that was formulated with a coconut water kefir (CWK) starter culture containing 9.60 log CFU/mL of L. plantarum, without dry yeast and fermented for 24 h, had significantly higher values for almost all amino acids and a lower protein content compared to samples formulated using CWK cultures containing 8.30 log CFU/mL of L. fermentum and 4.90 log CFU/mL of L. fermentum, both without dry yeast and fermented for 24 h. The bread sample formulated with CWK starter culture containing 9.60 log CFU/mL of L. plantarum, without dry yeast and fermented for 24 h, also produced significant quantities of organic acids (pyruvic acid, acetic acid, lactic acid and succinic acid). These changes in the physicochemical properties can improve overall bread quality in terms of flavor, shelf life, texture and nutritional value.

Background soundscapes influence the perception of ice-cream as indexed by electrophysiological measures

Listening to specific soundscapes can influence multisensory flavour perception. In the present study, changes in people's perception of the flavour of ice-cream were tracked over time as they listened to a café soundscape, and when this soundscape was overlaid with either bird, machine, or forest soundscapes. In addition, emotions and electrophysiological measures were recorded in order to help understand any changes in taste/flavour perception. The results of Temporal Dominance of Sensation (TDS) analysis revealed that cocoa was dominant early in the consumption episode while listening to the control café soundscape. Sweetness and creaminess were dominant at the start of the consumption episode while listening to the café-forest soundscape. Creaminess was dominant at the start of the consumption episode while listening to the café-bird soundscape. Bitterness was perceived at the end of the consumption period while listening to the café control and café-machine soundscapes. These findings demonstrate the crossmodal influence of audition on perception in the chemical senses. As expected, negative emotions were significantly higher when listening to the machine soundscape, while positive emotions were significantly higher when listening to café-forest and café-bird soundscapes. Evaluating ice-cream while listening to the café-machine soundscape evoked negative emotions associated with bitterness and creaminess, that were also associated with increased heart rate (HR) and respiration rate (RESP). When listening to the café-forest soundscape, ice-cream was associated with sweetness, and positive emotions (e.g., love, satisfaction, happiness, amusement and enjoyment). This might have led to increased blood volume pulse (BVP) amplitude, which is itself indicative of a relaxed state. Enhancing eating experiences by means of atmospheric soundscapes that are designed specifically to accentuate specific aspects of multisensory taste/flavour perception is currently an area of interest in the food sciences literature and will likely lead to future commercial applications.

Environmental Sounds Influence the Multisensory Perception of Chocolate Gelati

Recently, it has been shown that various auditory stimuli modulate flavour perception. The present study attempts to understand the effects of environmental sounds (park, food court, fast food restaurant, cafe, and bar sounds) on the perception of chocolate gelato (specifically, sweet, bitter, milky, creamy, cocoa, roasted, and vanilla notes) using the Temporal Check-All-That-Apply (TCATA) method. Additionally, affective ratings of the auditory stimuli were obtained using the Self-Assessment Manikin (SAM) in terms of their valence, arousal, and dominance. In total, 58 panellists rated the sounds and chocolate gelato in a sensory laboratory. The results revealed that bitterness, roasted, and cocoa notes were more evident when the bar, fast food, and food court sounds were played. Meanwhile, sweetness was cited more in the early mastication period when listening to park and café sounds. The park sound was significantly higher in valence, while the bar sound was significantly higher in arousal. Dominance was significantly higher for the fast food restaurant, food court, and bar sound conditions. Intriguingly, the valence evoked by the pleasant park sound was positively correlated with the sweetness of the gelato. Meanwhile, the arousal associated with bar sounds was positively correlated with bitterness, roasted, and cocoa attributes. Taken together, these results clearly demonstrate that people's perception of the flavour of gelato varied with the different real-world sounds used in this study.

Neural Correlates of Preference: A Transmodal Validation Study

Liking is one of the most important psychological processes associated with the reward system, being involved in affective processing and pleasure/displeasure encoding. Currently, there is no consensus regarding the combination of physiological indicators which best predict liking, especially when applied to dynamic stimuli such as videos. There is a lack of a standard methodology to assess likeability over time and therefore in assessing narrative and semantic aspects of the stimulus. We developed a time-dependent method to evaluate the physiological correlates of likeability for three different thematic categories, namely: adventure (AV), comedy (CM), and nature landscape (LS). Twenty-eight healthy adults with ages ranging from 18 to 35 years (average: 23.85 years) were enrolled in the study. The participants were asked to provide likeability ratings for videos as they watched them, using a response box. Three 60-s videos were presented, one for each category, in randomized order while the participant’s physiological data [electroencephalogram (EEG), electrocardiogram (ECG) and eye tracking (ET)] was recorded. The comedy video (CM) presented the smallest minimum accumulated normalized rating (ANR; p = 0.013) and the LS video presented the highest maximum ANR (p = 0.039). The LS video presented the longest time for first response (p < 0.001) and the AV video presented the shortest time for maximum response (p = 0.016). The LS video had the highest mean likeability rating with 1.43 ± 2.31 points; and the CM video had the lowest with 0.57 ± 1.77. Multiple linear regression models were created to predict the likeability of each video using the following physiological indicators; AV: power in beta band at C4 and P4 (p = 0.004, adj. R² = 0.301); CM: alpha power in Fp2 (p = 0.001, adj. R² = 0.326) and LS: alpha power in P4, F8, and Fp2; beta power in C4 and P4 and pupil size, (p = 0.002, adj. R² = 0.489). Despite its limitations (e.g., using one 1-min video per category) our findings suggest that there is a considerable difference in the psychophysiological correlates of stimuli with different contextual properties and that the use of time-dependent methods to assess videos should be considered as best practices.

Coffee Drinking and Emotions: Are There Key Sensory Drivers for Emotions?

In the past couple of decades the coffee market has exploded, and to remain competitive, it is important to identify the key drivers for consumer acceptance of coffee. This study expanded on the previous emotion study on a population of coffee drinkers in Manhattan, Kansas, USA and focused on identifying the sensory drivers of emotional responses elicited during the coffee drinking experience (CDE). A trained coffee panel performed a descriptive analysis of six coffee samples and identified the key sensory attributes that discriminated each coffee. Utilizing Partial Least Square Regression (PLSR), the descriptive data were then mapped with the emotion data to identify sensory drivers for eliciting the emotional responses. The sensory characteristics of dark roast coffee (roast–aroma and flavor, burnt–aroma and flavor, bitter, and body) might elicit positive-high energy feelings for this population of coffee users. Tobacco (flavor) and cocoa (aroma) may also be responsible for positive emotions (content, good, and pleasant). Citrus and acidity seemed to be negative sensory drivers as they induced the feeling of off-balance. Sensory descriptive data could be useful to describe emotion profiles elicited by coffee drinking, which could help the coffee industry create coffee products for different segments of coffee drinkers.

Cross-cultural effects of food product familiarity on sensory acceptability and non-invasive physiological responses of consumers

This research evaluated the effects of product familiarity on the sensory acceptability and physiological responses of consumers toward different food stimuli using two populations (Asian vs. Western). Two studies were conducted: (1) an online questionnaire and (2) a tasting session. For (1), n = 102 (60% Asians and 40% Westerners) evaluated 31 food items visually for familiarity and liking whereas for (2), participants (n = 60; 48% Asians and 52% Westerners) evaluated 10 different foods (tortoise jelly, chili slices, beef jerky, dried tofu, Vegemite®, durian cake, octopus chips, chocolate, corn chips, and wasabi coated peas) by tasting for familiarity and liking (visual/aroma/taste/texture/overall). A novel Android® app (Bio-sensory App) was used to capture sensory and non-invasive physiological responses (temperature, heart rate and facial expressions) of consumers. In (1), Asian and Western participants differed in their familiarity scores, visual liking ratings, and the selection of emotion terms for the stimuli. In (2), cultural differences affected familiarity and the liking scores of appearance, aroma, taste and texture of the products. While food stimuli marginally affected the physiological responses of consumers for both cultures, Asian participants elicited higher temperature values compared to those of Westerners. Both studies (1 and 2) showed that familiarity of food products was positively associated to sensory liking for both cultural groups. These findings are useful to understand consumers acceptability based on both sensory and physiological responses.

Effects of emotional responses to certain foods on the prediction of consumer acceptance

This research was focussed on the development of a methodology for the recognition of consumer preferences based on a combination of emotional, behavioural, and sensory trait information. A model of the impact of customers' sensory experiences on their attitudes towards food products and their behavioural intentions was analysed. Sensory and emotional analyses were used to describe five kinds of bread (wheat, rye, corn, wholemeal, and multigrain) and two types of chocolate (dark and milk). Acceptability and emotional response were rated by a consumer panel (n = 109) drawn from 21 to 24 age segments using the hedonic scores and a FaceReader software which detects six basic emotions (happy, sad, angry, disgusted, scared, surprised) and a neutral state were applied. For the products tested, expressions of happiness, anger, and sadness for each product were relatively high compared to the others, with the neutral state being the main expression. The chocolate products elicited the highest intensity of happiness, reducing the level of the neutral state. A different tendency was obtained during the testing of bakery goods: higher expression of the neutral state and sadness and low expression of happiness. The emotional/sensory experience model and consumer behavioural patterns comprise the method for the differentiation of products, which could be useful in the food industry as well as for the development of new methodologies for the prediction of changes in human emotional response to food related to psychological disorders.