Exploring within-meal variety to promote appeal of home-cooked meals in older adults

Undernutrition is highly prevalent in older adults and poses a major threat to physical and mental wellbeing. To foster healthy eating (and healthy aging), strategies are needed to improve dietary quality of older adults. In this study, the feasibility of increasing food variety in home-cooked meals is explored as strategy to promote meat and vegetable consumption in community dwelling older adults. Adults aged 50 years or older (N = 253) evaluated pictures of traditional Dutch dinner meals with more or less variety in the vegetable or meat component in an online questionnaire. Specifically, four different variety 'levels' were presented: (1) no variety, (2) meat variety, (3) vegetable variety, and (4) variety in both meat and vegetables (mixed). Participants indicated for each meal picture how much they would like the meal, whether it represented an ideal portion size, and whether they would be able and willing to prepare the meal. We expected that with increasing variety, liking and ideal portion size would increase, while ability and willingness to prepare the meals would decrease. Results showed that the meals with meat variety and mixed variety were liked less than meals with vegetable variety or no variety. Participants were all highly willing to prepare the meals, but they were less willing to prepare the meals with meat variety and mixed variety compared to the meals with vegetable variety and no variety. All meals were evaluated as being too large, but the meals with vegetable variety and mixed variety were evaluated as more oversized than the meals without variety and with meat variety. These results suggest that encouraging older adults to include variety in home-cooked meals might be more challenging than anticipated.

Meat- and plant-based products induced similar satiation which was not affected by multimodal augmentation

Little is known about how plant-based products influence satiation compared to corresponding meat-based products. As augmented reality (AR) intensifies sensory experiences, it was hypothesized to improve satiation. This study compared satiation between intake of meatballs and plant-based balls and plant-based balls intensified with AR for visual, olfactory, and haptic sensory properties. Intake order of the meatballs, plant-based balls, and augmented plant-based balls, eaten on separate days, was randomized. Satiation was measured from twenty-eight non-obese adults as ad libitum intake of the balls and extra snacks, and as subjective appetite sensations. Liking and wanting to eat the products were also investigated. There were no differences between the products in satiation. Before tasting the augmented plant-based balls were less liked than the meatballs (p = 0.002) or plant-based balls (p = 0.046), but after eating the first ball or eating the ad libitum number of balls the differences in liking disappeared. Wanting evaluations were similar for each product and decreased during eating (p < 0.001). A group of participants susceptible to AR was found (n = 11), described by decreased intake when augmentation was applied. Among the sub-group, wanting to eat the augmented balls was lower before tasting (p = 0.019) and after eating the first ball (p = 0.002) and appetite was less suppressed after eating the balls ad libitum (p = 0.01), when compared to non-susceptible participants. We conclude that meatballs and plant-based balls were equal in inducing satiation, and multisensory augmentation did not influence satiation. However, the augmentation decreased liking evaluations before tasting. Further studies are needed to explore differences between consumer groups in susceptibility to augmentation.

Does sweetness exposure drive 'sweet tooth'?

It is widely believed that exposure to sweetened foods and beverages stimulates the liking and desire for sweetness. Here we provide an updated review of the empirical evidence from human research examining whether exposure to sweet foods or beverages influences subsequent general liking for sweetness (‘sweet tooth’), based on the conclusions of existing systematic reviews and more recent research identified from a structured search of literature. Prior reviews have concluded that the evidence for a relationship between sweet taste exposure and measures of sweet taste liking is equivocal, and more recent primary research generally does not support the view that exposure drives increased liking for sweetness, in adults or children. In intervention trials using a range of designs, acute exposure to sweetness usually has the opposite effect (reducing subsequent liking and desire for sweet taste), while sustained exposures have no significant effects or inconsistent effects. Recent longitudinal observational studies in infants and children also report no significant associations between exposures to sweet foods and beverages with measures of sweet taste preferences. Overall, while it is widely assumed that exposure to sweetness stimulates a greater liking and desire for sweetness, this is not borne out by the balance of empirical evidence. While new research may provide a more robust evidence base, there are also a number of methodological, biological and behavioural considerations that may underpin the apparent absence of a positive relationship between sweetness exposure and liking.

Relationship between opioid cross-tolerance during buprenorphine stabilization and return to opioid use during buprenorphine dose tapering

RATIONALE

Opioid injection drug use (IDU) has been linked to a more severe pattern of use (e.g. tolerance, overdose risk) and shorter retention in treatment, which may undermine abstinence attempts.

OBJECTIVES

This secondary data analysis of four human laboratory studies investigated whether current opioid IDU modulates subjective abuse liability responses to high-dose hydromorphone during intermediate-dose buprenorphine stabilization (designed to suppress withdrawal but allow surmountable agonist effects), and whether hydromorphone response magnitude predicts latency of return to opioid use during buprenorphine dose-tapering.

METHODS

Regular heroin users not currently seeking treatment (n = 54; 29 current injectors, 25 non-injectors) were stabilized on 8-mg/day sublingual buprenorphine and assessed for subjective responses (e.g. 'liking', craving) to hydromorphone 24-mg intramuscular challenge (administered 16-hr post-buprenorphine) under randomized, double-blinded, controlled conditions. A subgroup (n = 35) subsequently completed a standardized 3-week outpatient buprenorphine dose-taper, paired with opioid-abstinent contingent reinforcement, and were assessed for return to opioid use based on thrice-weekly urinalysis and self-report.

RESULTS

During buprenorphine stabilization, IDU reported lower 'liking' of buprenorphine and post-hydromorphone peak 'liking', 'good effect' and 'high' compared to non-IDU. Less hydromorphone peak increase-from-baseline in 'liking' (which correlated with less hydromorphone-induced craving suppression) predicted significantly faster return to opioid use during buprenorphine dose-tapering.

CONCLUSIONS

In these buprenorphine-stabilized regular heroin users, IDU is associated with attenuated 'liking' response (more cross-tolerance) to buprenorphine and to high-dose hydromorphone challenge and, in turn, this cross-tolerance (but not IDU) predicts faster return to opioid use. Further research should examine mechanisms that link cross-tolerance to treatment response.

What's cooking, if not meat? Effects of repeated home-use, recipe inspiration and meal context on perception of plant-based meat analogues

Plant-based meat analogues (PBMA) may help consumers in shifting towards more plant-based diets, but PBMA are not widely used yet, and little is known about their longer-term acceptance. This study investigated whether consumer acceptance of PBMA changed with repeated home-use, and whether providing recipe suggestions in the form of meal boxes could influence PBMA acceptance. To this end, Dutch regular meat eaters (n = 61) prepared, consumed and evaluated two meals (one from a meal box, one self-created) with PBMA (PB mince and PB chicken, counterbalanced across meal types) per week at home for four weeks. As a secondary objective, potential longer-term effects of repeated home-use of PBMA on meat (analogue) consumption habits and attitudes (e.g. motives for choosing PBMA, attitudes toward eating less meat) were assessed in a pre-vs post-intervention survey. Responses were compared with a control group of consumers not participating in the home-use study (n = 179). Results provided no evidence that PBMA liking changed with repeated home-use, nor that the provision of meal boxes increased liking of PBMA. Instead, PBMA liking was strongly influenced by the meal context, which may have overruled potential effects of repeated exposure. Findings from the pre- vs. post-intervention survey suggest that repeated exposure may stimulate longer-term consumption of PBMA, although more seems needed to bring about a structural shift toward a less animal-based consumption pattern. Future research should investigate whether more sophisticated recipes that provide a suitable meal context for PBMA and elevate consumers' meal experiences may improve PBMA acceptance and facilitate the transition toward more sustainable diets.

Evidence that carbohydrate-to-fat ratio and taste, but not energy density or NOVA level of processing, are determinants of food liking and food reward

This virtual (online) study tested the common but largely untested assumptions that food energy density, level of processing (NOVA categories), and carbohydrate-to-fat (CF) ratio are key determinants of food reward. Individual participants (224 women and men, mean age 35 y, 53% with healthy weight, 43% with overweight or obesity) were randomised to one of three, within-subjects, study arms: energy density (32 foods), or level of processing (24 foods), or CF ratio (24 foods). They rated the foods for taste pleasantness (liking), desire to eat (food reward), and sweetness, saltiness, and flavour intensity (for analysis averaged as taste intensity). Against our hypotheses, there was not a positive relationship between liking or food reward and either energy density or level of processing. As hypothesised, foods combining more equal energy amounts of carbohydrate and fat (combo foods), and foods tasting more intense, scored higher on both liking and food reward. Further results were that CF ratio, taste intensity, and food fibre content (negatively), independent of energy density, accounted for 56% and 43% of the variance in liking and food reward, respectively. We interpret the results for CF ratio and fibre in terms of food energy-to-satiety ratio (ESR), where ESR for combo foods is high, and ESR for high-fibre foods is low. We suggest that the metric of ESR should be considered when designing future studies of effects of food composition on food reward, preference, and intake.

Salivary microbial profiles associate with responsiveness to warning oral sensations and dietary intakes

Oral microbiota-host interactions are gaining recognition as potential factors contributing to interindividual variations in taste perception. However, whether such possible links imply specific bacterial co-occurrence networks remains unknown. To address this issue, we used 16 s rRNA gene sequencing to profile the salivary microbiota of 100 healthy individuals (52 % women; 18-30 y/o), who provided hedonic and psychophysical responses to 5 liquid and 5 solid commercially-available foods, each chosen to elicit a target sensation (sweet, sour, bitter, salty, pungent). The same cohort also completed several psychometric measures and a 4-day food diary. Unsupervised data-driven clustering of genus-level Aitchison distances supported the existence of two salivary microbial profiles (CL-1, CL-2). While CL-1 (n = 57; 49.1 % women) exhibited higher α-diversity metrics and was enriched in microbial genera assigned to the class Clostridia (e.g., Lachnospiraceae_[G-3]), CL-2 (n = 43; 55.8 % women) harbored greater amounts of taxa with potential cariogenic effects (e.g., genus Lactobacillus) and significantly lower abundances of inferred MetaCyc pathways related to the metabolic fate of acetate. Intriguingly, CL-2 showed enhanced responsiveness to warning oral sensations (bitter, sour, astringent) and a higher propensity to crave sweet foods or engage in prosocial behaviors. Further, the same cluster reported habitually consuming more simple carbohydrates and fewer beneficial nutrients (vegetable proteins, monounsaturated fatty acids). In summary, while the mediating role of participants' baseline diet on findings can not be definitively excluded, this work provides evidence suggesting that microbe-microbe and microbe-taste interactions may exert an influence on dietary habits and motivates further research to uncover a potential "core" taste-related salivary microbiota.

Hedonic Overeating-Questionnaire: Exploring interactive effects between wanting, liking, and dyscontrol on body mass index

The Hedonic Overeating-Questionnaire is a brief self-report measure for the trait assessment of liking (pleasure to eat; consummatory reward component), wanting (food craving; anticipatory reward component), and dyscontrol (loss of control over eating). In the original validation study, higher scores on each of the three subscales related to higher body mass index (BMI). However, theories on food reward and self-regulation suggest that overeating and obesity may also result from interactions between these aspects. Therefore, we reanalyzed the data of the original, cross-sectional study (N = 2504, 53% female) and explored whether liking, wanting, and dyscontrol scores interactively predicted BMI. Indeed, there was a significant interaction effect Wanting × Dyscontrol on BMI such that higher dyscontrol scores related to higher BMI, particularly at high wanting scores. The other two-way interactions and the three-way interaction were not significant. Results do not support certain theories on food reward (e.g., the incentive-sensitization theory of addiction and its application to obesity), which would suggest an interactive effect between liking and wanting on BMI. However, they do support dual systems models of self-regulation that suggest that overeating and obesity result from an interplay of strong bottom-up impulses (here: wanting) and weak top-down control (here: dyscontrol).

Shape of my likes: how explicit and implicit reference frames shape the liking of insect-based protein bar

A high-protein bar incorporating mealworm powder was developed. The impact of explicit and implicit frame formation on the acceptance and sensory characteristics of this target bar was investigated by comparing it with four commercial protein bars for a total of 275 consumers. To construct the explicit frame, consumers watched a video clip about each frame (environment/nutrition/meal replacement) just before the evaluation. In the no-explicit-frame group, five protein bars were evaluated without video priming. The control group tasted the target sample only without any information. The implicit framework formed during the progress of exposure to various protein bar samples had a greater influence than explicit cues on the acceptance of the target. Promoting the nutritional and environmental merits of edible insects was not sufficient to improve the acceptability of the insect-incorporated protein bar. The liking decreased significantly with the inclusion of the commercial samples during the progress of sequential monadic serving.

A social norm intervention increases liking and intake of whole crickets, and what this tells us about food disgust

Edible insects are healthy and sustainable but are rejected as food in Western populations due to disgust. We tested the effectiveness of written interventions to reduce disgust and increase intake of whole crickets. Cricket acceptance after reading a descriptive social norm or food preparation intervention passage was compared with a control passage, and an unfamiliar but non-disgusting food (leblebi, roasted chickpeas). Participants (N = 120) were randomised to one of four conditions (control + crickets, food preparation + crickets, social norm + crickets and control + leblebi). Outcome measures included taste pleasantness, desire to eat, food intake and, to measure disgust, self-report disgust, tactile sensitivity and latency to eat. In the control condition, crickets were rejected due to disgust and low desire to eat. In comparison, in the social norm condition, crickets were rated as tasting more pleasant, more desirable, and less disgusting, and intake was greater. The food preparation passage had a small but positive effect on cricket intake. For the first time, this study shows that a descriptive social norm can affect eating behaviour even when a food is disgusting; however, a food preparation intervention cannot overcome high disgust. The pattern of results suggested that expected and perceived taste pleasantness affects disgust. Therefore, taste quality and normalising consumption are targets for promoting acceptance of insects, and probably other novel, sustainable foods.

It tastes OK, but I don't want to eat it: New insights into food disgust

To better understand food-disgust, we investigated the long-standing theory that disgust towards a food causes it to taste 'bad'. To induce disgust, participants were served cookies labelled as containing crickets (Study 1); or served whole crickets versus novel (leblebi) and familiar (peanuts) control foods (Study 2). Participants (Study 1: N = 80; Study 2: N = 90) tasted the foods and rated taste pleasantness, desire to eat, disgust and, in Study 1, 16 taste attributes (e.g., nuttiness). Latency to eat and food intake were included as behavioural indicators of disgust. In both studies disgusting foods were presumed to taste bad, but this was disconfirmed after tasting - disgust did not cause the food to taste bad. Nonetheless, the taste attribute results suggested increased attention towards cricket flavours/textures. Furthermore, desire to eat and intake results suggested that disgust, but not novelty, was associated with reduced food wanting. Even if a disgust-inducing food tastes OK, people do not 'want' to consume it. By offering novel insights into our understanding of disgust, these results may stimulate progress in new avenues of emotion research, as well as informing the development of methods to reduce disgust and increase the acceptance of novel, sustainable, foods. For example, interventions should encourage tasting to overcome negative expectations of taste pleasantness and should tackle low levels of wanting, e.g., by normalising consumption of the target food.

High arousal as the source of food rejection in food neophobia

Food neophobia (FN) at moderate to high levels is very common among adult populations in all cultures and is usually defined in terms of rejection of unfamiliar foods. However, food rejection in FN is only partly related to food familiarity. Experimental and survey studies have suggested that unpleasantly high arousal may be induced by food novelty, but also be produced by foods with intense or complex flavours, that are perceived as dangerous or foreign, or that have unusual ingredients. Liking for foods with these characteristics have recently been shown to be strongly negatively associated with FN. Thus, induced high arousal may underlie food rejection in FN. Here, we collected familiarity, liking and arousal ratings, and scores on the standard Food Neophobia Scale from more than 7000 consumers in four countries - Australia, United Kingdom, Singapore, Malaysia - for a series of food names that were manipulated to produce standard and 'high arousal' (variant) versions of the same foods. Consistent across all four countries, arousal ratings increased, and liking decreased, with decreases in food familiarity. Variant food names were always associated with ratings of higher arousal than the standard names. The variant foods were generally less familiar than the standard foods, although this was not a necessary condition for their higher arousal ratings, suggesting that the other arousal-inducing factors (e.g., flavour intensity) also played a role. Across all foods, arousal ratings increased, and liking ratings decreased, as FN increased, but these effects were accentuated for the variant foods. The consistency of these effects across multiple countries supports a view that arousal is universally a strong determinant of liking for foods and that this underlies the rejection of foods, familiar and novel, in FN.

Home-based cooking intervention with a smartphone app to improve eating behaviors in children aged 7-9 years: a feasibility study

Objective

To develop and evaluate the feasibility of a mobile application in Swiss households and assess its impact on dietary behavior and food acceptability between children who cooked with limited parental support (intervention group) with children who were not involved in cooking (control group).

Methods

A ten-week randomized controlled trial was conducted online in 2020. Parents were given access to a mobile-app with ten recipes. Each recipe emphasized one of two generally disliked foods (Brussels sprouts or whole-meal pasta). Parents photographed and weighed the food components from the child's plate and reported whether their child liked the meal and target food. The main outcome measures were target food intake and acceptability analyzed through descriptive analysis for pre-post changes.

Results

Of 24 parents who completed the baseline questionnaires, 18 parents and their children (median age: 8 years) completed the evaluation phase. Mean child baseline Brussel sprouts and whole-meal pasta intakes were 19.0 ± 24.2 g and 86.0 ± 69.7 g per meal, respectively. No meaningful differences in intake were found post-intervention or between groups. More children reported a neutral or positive liking towards the whole-meal pasta in the intervention group compared to those in the control group. No change was found for liking of Brussel sprouts.

Conclusions for practice

The intervention was found to be feasible however more studies on larger samples are needed to validate feasibility. Integrating digital interventions in the home and promoting meal preparation may improve child reported acceptance of some healthy foods. Using such technology may save time for parents and engage families in consuming healthier meals.

Decreased retronasal olfaction and taste perception in obesity are related to saliva biochemical and microbiota composition

Understanding the individual factors that modulate flavor perception is a central issue for the development of personalized diets strategies to fight obesity. This study aimed to investigate differences in flavor perception between adults with normal weight and those with obesity, as well as some potential biological factors related to these differences. To do that, liking and flavor perception intensity were measured against retronasal olfactory (pineapple, butter, tropical and chocolate) and taste attributes (sweetness, umami and bitter) in 77 individuals grouped as normalweight or obese, according to their body mass index (BMI). Unstimulated saliva was collected from all participants and characterized in terms of salivary flow, total protein content, total antioxidant capacity, total esterase activity and bacterial composition through 16S rDNA amplicon sequencing. The results showed that participants displayed differences in flavor perception according to their BMI group. Thus, the group with obesity showed significant lower liking and intensity scores for low calorie related food aroma (pineapple and tropical), lower taste intensity scores for sweet and umami, and a higher acceptability for umami than the group with normal weight. Significant differences between BMI groups were observed for salivary biochemical variables and specific bacterial taxa, some of which were significantly correlated to flavor intensity. This work suggests for the first time the existence of an oral-brain axis that might contribute to the development or perpetuation of obesity, which opens new and interesting avenues of research.

Transcranial direct current stimulation (tDCS) to dorsolateral prefrontal cortex influences perceived pleasantness of food

The ability to regulate the intake of unhealthy foods is critical in modern, calorie dense food environments. Frontal areas of the brain, such as the dorsolateral prefrontal cortex (DLPFC), are thought to play a central role in cognitive control and emotional regulation. Therefore, increasing activity in the DLPFC may enhance these functions which could improve the ability to reappraise and resist consuming highly palatable but unhealthy foods. One technique for modifying brain activity is transcranial direct current stimulation (tDCS), a non-invasive technique for modulating neuronal excitability that can influence performance on a range of cognitive tasks. We tested whether anodal tDCS targeting the right DLPFC would influence how people perceived highly palatable foods. In the present study, 98 participants were randomly assigned to receive a single session of active tDCS (2.0 mA) or sham stimulation. While receiving active or sham stimulation, participants viewed images of highly palatable foods and reported how pleasant it would be to eat each food (liking) and how strong their urge was to eat each food (wanting). We found that participants who received active versus sham tDCS stimulation perceived food as less pleasant, but there was no difference in how strong their urge was to eat the foods. Our findings suggest that modulating excitability in the DLPFC influences "liking" but not "wanting" of highly palatable foods. Non-invasive brain stimulation might be a useful technique for influencing the hedonic experience of eating but more work is needed to understand when and how it influences food cravings.

Testing reward processing models of obesity using in-the-moment assessments of subjective enjoyment of food and non-food activities

OBJECTIVE

Although altered reward processing is proposed to play a key role in obesity maintenance, the role of food enjoyment and enjoyment of non-food naturally rewarding activities ("non-food enjoyment") in obesity maintenance remains unknown. This study examined how food and non-food enjoyment were associated with baseline body mass index (BMI) and weight loss (WL) following year-long behavioral WL treatment.

METHODS

At baseline, participants (MAge = 51.81; 73.8 % White, N = 279) with overweight/obesity completed a 7-day ecological momentary assessment (EMA) protocol inquiring about pleasure/enjoyment derived from eating and non-food activities over the past few hours. Participants also completed retrospective self-report measures of food/non-food enjoyment. With linear regressions, associations between EMA food/non-food enjoyment and BMI and post-treatment WL were examined. Race was included as a covariate.

RESULTS

EMA and retrospective food/non-food enjoyment measures had modest concordance, providing preliminary psychometric support for the EMA measures. Partially consistent with hypotheses, greater EMA food enjoyment was associated with lower BMI (B = -1.03, p = .01) and with greater WL, though the latter association was not statistically significant (B = 1.15, p = .07). Exploratory analyses suggested that race was associated with food enjoyment (non-White participants had greater food enjoyment than White participants, d = 0.81, p = .005), and that race may have affected associations between food enjoyment and weight outcomes. Associations between non-food enjoyment and weight outcomes were small and nonsignificant (ps > .93).

CONCLUSIONS

Results suggest enjoyment from food, but not from non-food domains, is associated with weight outcomes.

The role of expectations for liking and other positive Affiliative outcomes in the get-acquainted process that occurs over Computer-mediated video communication

People often develop expectations prior to meeting someone for the first time. These pre-interaction expectations, which include how much they will like the other and how much they will enjoy the interaction, have likely increased because of information easily obtained about others through social media. What is not well understood is whether these expectations prior to a first meeting are associated with interpersonal evaluations formed during the get-acquainted interaction. In this study, pre-interaction expectations were collected from both members of 71 dyads. Then, after the dyads interacted through a structured self-disclosure task conducted over Skype, their reactions were assessed again. Several findings of the study have implications for people meeting for the first time, including over visual forms of computer-mediated communication (CMC). Findings included that pre-interaction expectations were associated with reactions after the interaction, a visual greeting with another before learning information about the other did not moderate the effect of that information on liking and other affiliative outcomes, and participants underestimated how much they were liked after the interaction. The implications of the findings are important because people are increasingly becoming acquainted through visual forms of CMC, which has been amplified during the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-021-01466-4.

A dataset on the sensory and affective perception of Bordeaux and Rioja red wines collected from French and Spanish consumers at home and international wine students in the lab

This article describes a dataset providing temporal sensory descriptions and affective answers for red wines: two Bordeaux and two Riojas. The wines were tasted at home by French (FR, n=106) and Spanish (SP, n=98) consumers and in the lab by wine students (WC, n=47). Standardized information was displayed on the samples (country and region of origin, name, producer, vintage, alcohol content). The FR and SP panels were split into three groups, the first having no rating information, the second having expert rating information (based on Wine Advocate ratings), and the third having consumer rating information (based on online Vivino reviews). The participants first rated their expected liking for the four wines. Then, for each wine sample, they had (in order) to taste the sample while being video recorded, rate their liking, temporally describe the sequence of sensations they perceived using Free-Comment Attack-Evolution-Finish, answer several questions about familiarity and quality perception, and declare their willingness to pay (reserve price). Then, they had to rank the four wines according to their quality. General questions about wine involvement, subjective wine knowledge, valuation behaviour, purchasing, and consumption patterns were asked. Finally, an auction was resolved: participants declaring a reserve price greater than the drawn price won a bottle. The data were used to assess the influence of culture and expertise on temporal sensory evaluations in an article entitled "Using Free-Comment to investigate expertise and cultural differences in wine sensory description". The data can be reused by researchers interested in studying the impact of external information on preferences and choices or investigating the sensory drivers of liking.

Putting your best face forward: How instructor emoji use influences students' impressions of credibility, immediacy, and liking

This project explores the impacts of emojis on students' impressions when used in a course welcome email. We adopt a 4 × 3 factorial design to determine how different emojis (i.e., , , ) impact students' impressions of credibility, immediacy, and liking. Data from students (N = 368) indicates emoji choice does impact impressions. Consistently, instructors' emoji use resulted in decreased perceived competence and trustworthiness but increased perceived caring, immediacy, and liking. Findings have implications for instructors who engage in technologically-mediated out-of-class communication and want to strengthen early student-instructor relationships. Limitations and future directions are also discussed.

The reward positivity is sensitive to affective liking

The EEG feature known as the Reward Positivity (RewP) is elicited by reward receipt and appears to reflect sensitively and specifically positive prediction errors during reinforcement learning. Yet, the RewP also is modulated by state and trait affect, suggesting that it has a more complex computational role than simple reinforcement surprise. We conducted a series of experiments aimed to investigate underlying affect processing reflected in the RewP during a reinforcement learning task. In the first experiment (N = 25), we manipulated the type of rewards a person could win (simple points or hedonically-appraised pictures). Although there were no differences in the amplitudes of the RewP for different types of rewards, there was a significant correlation between the individual rating of liking for the images and RewP amplitude. In a second experiment (N = 25), we manipulated reinforcement rates (easy vs. hard) and affective picture content (liked vs. ambivalent) to examine the potential interaction of prediction error and liking on RewP amplitude. We again found a significant relationship between liking and RewP amplitude, however, only in the hard condition. These findings suggest that the RewP reflects cortical computations of reward surprise as well as hedonic liking, identifying it as a possible nexus where multidimensional value is computed.

Consumer evaluation of meat quality from barrows, immunocastrates and boars in six countries

The practice of surgical castration of piglets and its alternatives is still under debate. Production of boars may impair meat quality due to boar taint and reduced tenderness compared to meat from surgically castrated male pigs, while immunocastration reduces boar taint and may improve meat quality but seems to be less accepted by the pig chain. In this study, we aimed to evaluate the consumer's sensory appreciation of meat from barrows (BAs), immunocastrates (ICs) and boars (BOs) in six European countries, taking into account the selection of tainted carcass and consumers' appreciation of boar taint. Loin chops of 30 BAs, 30 ICs and 30 BOs were evaluated by 752 consumers in six countries: Belgium, Czech Republic, Poland, Portugal, Romania and Spain. Consumers rated odour, flavour, tenderness, juiciness, overall liking and willingness to buy and sensitivity to and liking of androstenone (AND) and liking of skatole (SKA) was also tested. In each of the six countries, consumers liked the odour of the BO samples less than that of BA, and IC intermediate. For flavour, tenderness, juiciness, overall liking and willingness to buy, liking scores given by the Czech, Polish and Portuguese consumers significantly differed between the BA, BO and IC. Willingness to buy was highest for BA by Czech and Polish consumers and for BA and IC by Portuguese consumers. The frequency of the negative check all terms that apply terms also differed, with a higher frequency of disgusting for BO compared to BA and IC and of off-flavour, irritating, manure, sweat, disappointing compared to BA, and intermediate for IC. 31% of the consumers disliked the odour of AND (NEG_AND), and 36% of them were not sensitive; in contrast, 77% of the consumers disliked SKA (NEG_SKA). The decrease in flavour liking score for BO compared to BA and IC was more outspoken by the NEG_AND consumer, while NEG_SKA consumers gave an overall lower liking score independent of the type of male pig. The results of this study indicate that IC can be a valid alternative for surgical castration.

Enhanced conditioned "liking" of novel visual cues paired with alcohol or non-alcohol beverage container images among individuals at higher risk for alcohol use disorder

RATIONALE/OBJECTIVE

This study used an evaluative conditioning (EC) procedure to assess the affective properties of a CS for ingested drug reward in humans. Specifically, the study tested whether the evaluative response ("liking"/"disliking") to an arbitrary visual stimulus ("CS₂," e.g., a purple hexagon) could be changed through pairings with an alcohol or non-alcohol beverage cue ("CS₁," e.g., a full wine glass, a juice box), which is ostensibly a conditioned visual predictive stimulus for alcohol or non-alcohol liquid reward, respectively.

METHODS

Participants (N = 369, 18-23 years, 66% female, 79% white, 21% reporting no alcohol use ever or in the past year) received 24 CS₁ pairings with each CS₂. CS₂ and CS₁ evaluations were assessed pre- and post-conditioning.

RESULTS

Alcohol and non-alcohol CS₂ "liking" correlated with alcohol use. "Liking" of the alcohol but not non-alcohol CS₁ also correlated with alcohol use. Alcohol CS₁ "liking" also correlated with alcohol and non-alcohol CS₂ 'liking," whereas non-alcohol CS₁ 'liking" correlated with non-alcohol but not alcohol CS₂ "liking."

CONCLUSIONS

Taken together, findings support the idea that drug-related visual stimuli acquire appetitive (hedonic and/or incentive) properties as a function of individual differences in drug use, which entail individual differences in exposure to the conditioning effects of addictive substances like alcohol. Findings also suggest a link between drug use and the propensity to attribute affective/motivational significance to reward-predictive cues in general.

The impact of environmental sounds on food reward

Wanting and liking are both components of food reward, but they manifest in fundamentally different neural substrates. While wanting denotes anticipatory and motivational behaviors, liking is associated with consummatory and hedonic experiences. These distinct constructs have also been quantitatively dissociated in behavioral paradigms. Indeed, internal, physiological, and interoceptive states affect the degree to which the food presented is valued. However, how contextual sensory cues might impact these appetitive and rewarding responses to food remains unexplored. In light of the increasing empirical focus on sound in food research, we investigated the influence of environmental soundscapes on explicit liking, explicit wanting, implicit wanting, choice frequency, and reaction time of healthy/unhealthy food using an online version of the Leeds Food Preference Questionnaire (LFPQ). Soft nature sounds and loud restaurant noises were employed to induce emotional relaxation and arousal respectively. One hundred and one healthy university students completed a repeated-measure design of the LFPQ; once with each soundscape playing in the background. Generalized linear mixed model analyses detected a significant interaction effect between soundscape and food type on choice frequency, yet the post hoc analyses did not reach significance. No interaction effects between soundscape and food type on wanting or liking were discovered. However, hypothesis-driven analyses found that nature sounds increased explicit liking of healthy (vs. unhealthy) foods, while no effect of soundscape on any wanting measures (explicit or implicit) were observed. Finally, exploratory analyses indicated that restaurant noise (vs. nature sound) induced faster response times for both healthy and unhealthy foods. The study exemplifies that in an online setting, contextual auditory manipulation of certain food reward measures and decision processes is feasible.

Investigating the relative merits of using a mixed reality context for measuring affective response and predicting tea break snack choice

Sensory evaluation for the investigation of food consumption is often conducted in a controlled laboratory environment, which does not reflect consumption behaviour in real world. Here, we compared the effect of consumption setting (traditional sensory booth, mixed reality projection café, and a café) on consumer affective responses, and to investigate the effectiveness of using Microsoft HoloLens technology, an Augmented Mixed Reality device, as an ecologically valid alternative to natural consumption eating for sensory evaluation. Participant [(n = 120): 86 females/34 males, aged 18-65 years] affective response (overall liking, attribute liking, emotional response, and snack choice) towards two commercially available tea break snacks (caramel slice and chocolate digestive biscuit) was assessed in three different consumption settings using a balanced crossover design. There were no significant differences for most affective ratings between data obtained from the HoloLens evoked café and real café (p ≥ 0.10), suggesting that mixed reality could provide an ecologically valid context for consumer research. However, response differences were observed between these two contexts and the sensory booths. For example, interested, joy, enthusiastic emotion terms were rated slightly higher in the evoked café in comparison to the booth context and slightly higher emotional engagement was observed for joy in the café compared to the booths (all p < .10). This study highlights key considerations for deciding where consumer testing should be conducted and the importance of using a combination of overall liking, attribute liking and emotional response to obtain data representative of real-world environments in consumer studies.

Acute vagus nerve stimulation does not affect liking or wanting ratings of food in healthy participants

The vagus nerve plays a vital role in the regulation of food intake and vagal afferent signals may help regulate food cue reactivity by providing negative homeostatic feedback. Despite strong evidence from preclinical studies on vagal afferent "satiety" signals in guiding food intake, evidence from human studies is largely inconclusive to date. Here, we investigated the acute effects of left or right transcutaneous auricular vagus nerve stimulation (taVNS) on subjective ratings of wanting and liking of various food and non-food items in 82 healthy participants (46 women, M_BMI = 23.1 kg/m²). In contrast to previous reports in patients with depression, we found moderate to anecdotal evidence supporting the absence of taVNS-induced changes in food ratings. To test whether the absence of taVNS effects on food ratings is due to heterogeneity in the sample, we conducted post hoc subgroup analyses by splitting the data according to stimulation side and sex (between-subject factors) as well as caloric density, perceived healthiness, and flavor (sweet vs. savory) of the food (within-subject factors). This multiverse analysis largely supported the absence of taVNS-induced changes since the strongest subgroup effects provided only anecdotal evidence in favor of taVNS-induced changes. We conclude that acute taVNS only has a marginal effect on subjective ratings of food, suggesting that it is an unlikely mechanism for the reported long-term effects of VNS on body weight. In light of an absence of acute taVNS effects on conscious food liking and wanting, our results call for future research on the correspondence between acute and chronic effects of vagal afferent stimulation.

Remote testing: Sensory test during Covid-19 pandemic and beyond

Restrictions adopted by many countries in 2020 due to Covid-19 pandemic had severe consequences on the management of sensory and consumer testing that strengthened the tendency to move data collection out of the laboratory. Remote sensory testing, organized at the assessor’s home or workplace and carried out under the live online supervision of the panel leader, represents a trade-off between adequate control and the convenience of conducting testing out of the lab. The Italian Sensory Science Society developed the “Remote sensory testing” research project aimed at testing the effectiveness and validity of the sensory tests conducted remotely through a comparison with evaluations in a classical laboratory setting. Guidelines were developed to assist panel leaders in setting up and controlling the evaluation sessions in remote testing conditions. Different methods were considered: triangle and tetrad tests, Descriptive Analysis and Temporal Dominance of Sensations tests, all of which involved trained panels, and Check-All-That-Apply and hedonic tests with consumers. Remote sensory testing provided similar results to the lab testing in all the cases, with the exception of the tetrad test run at work. Findings suggest that remote sensory testing, if conducted in strict compliance with specifically developed sensory protocols, is a promising alternative to laboratory tests that can be applied with both trained assessors and consumers even beyond the global pandemic.

Bitter and sweet taste perception: relationships to self-reported oral hygiene habits and oral health status in a survey of Australian adults

Background

Oral health, an essential part of general health and well-being, is influenced by multiple factors, including oral hygiene habits and dietary factors. Dietary preferences are influenced by variation in taste perceptions and threshold tasting. Polymorphisms in specific genes for sweet and bitter taste receptors and bitter taste perception have been associated with dental caries. However, taste is complex with multiple receptors, each with multiple potential polymorphisms contributing to taste perception as well as social, cultural, and environmental influences. Additionally, these association studies have been conducted in restricted cohorts (e.g., children only). Furthermore, outcomes have been limited to dental caries and studies between taste perception and oral hygiene habits have not been completed.

Methods

A cross-sectional online survey was conducted to investigate the relationships between bitter and sweet taste perception (liking and intensity of index food items), self-reported oral hygiene habits and oral health (n = 518).

Results

Higher mean intensity scores for bitter (16–21%) and sweet (< 5%-60%) were seen with higher frequencies of oral hygiene habits (brushing, use of mouthwash, chewing gum and tongue cleaning). Lower mean bitter liking scores (18–21%) were seen with higher frequencies of oral hygiene habits (brushing, mouthwash use, floss use and chewing gum). Sweet liking scores varied by reported frequency of mouthwash use and flossing only, with mixed patterns of variance. Mean bitter and sweet intensity perception scores varied with the number of dental caries ((13–20% higher in those with 3 or more caries, compared to none).

Conclusions

While there were numerous relationships identified between liking and perception of sweet and bitter and oral health outcomes, the magnitude and direction of associations varied by outcome. The direction of the associations cannot be inferred due to the cross-sectional nature of the study. The demonstrated relationships justify further future investigations, which could help better understand if taste liking and perception is impacted by oral hygiene and health, or vice versa. This could be important in understanding the causation and progression of oral health diseases or the development of novel therapeutics for oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01910-8.

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.

Effects of tDCS on reward responsiveness and valuation in Parkinson's patients with impulse control disorders

Parkinson's disease (PD) patients with impulse control disorders (ICD) frequently report hypersensitivity to rewards. However, a few studies have explored the effectiveness of modulation techniques on symptoms experienced by these patients. In this study, we assessed the effect of anodal tDCS over the DLPFC on reward responsiveness and valuation in PD patients with ICD. 43 participants (15 PD patients with ICD, 13 PD without ICD, and 15 healthy matched controls) were asked to perform a reward-craving test employing both explicit (self-ratings of liking and wanting) and implicit (heart rate and skin conductance response) measures, as well as two temporal discounting tasks with food and money rewards. Each participant performed the experimental tasks during active anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC), anodal tDCS of the primary motor cortex (M1), and sham tDCS. Results showed increased wanting and a steeper temporal discounting of rewards in PD with ICD compared to the other groups. Moreover, we found that PD without ICD exhibit reduced liking for rewards. tDCS results capable to modulate the altered intensity of PD patients' liking, but not wanting and temporal discounting of rewards in PD patients with ICD. These findings confirm that alterations in reward responsiveness and valuation are characteristics of impulse control disorders in patients with PD but suggest that anodal tDCS over the left DLPFC is not capable to influence these processes. At the same time, they provide new insight into affective experience of rewards in PD.

A reward and incentive-sensitization perspective on compulsive use of social networking sites - Wanting but not liking predicts checking frequency and problematic use behavior

The use of Social Networking Sites (SNSs) has exponentially increased over the past decade, leading to warnings about the addictive potential of this technology. Yet, the idea of SNS addiction remains controversial and more theory-driven research is required to understand the mechanisms of excessive and compulsive SNS use and to facilitate the development of targeted interventions helping affected users. In the present article we propose to utilize a reward-based approach to further our understanding of these behaviors. In particular, we suggest that concepts borrowed from the drug addiction literature that focus on incentive processes (incentive-sensitization and cue reactivity) can explain some SNS behaviors, such as compulsive checking. One elemental finding of the neurobiological drug addiction literature is that repeated exposure to a rewarding substance can render the brain's reward system oversensitive to cues related to the drug. We report preliminary findings from 358 participants showing that cue-elicited urges to use SNSs characterized both excessive and problematic use behaviors. Moreover, desires and urges to use SNSs (wanting responses) could be reliably dissociated from the enjoyment and pleasure (liking responses) associated with SNSs, with the latter being less predictive of the intensity and problematicity of behaviors than the former. Such divergence between motivational and hedonic processes is another hallmark finding in the literature on drug and food rewards. Together our initial findings thus suggest that examining alterations of reward processes holds promise to explain the compulsive use of SNSs and to identify potential avenues to help affected individuals.

Evaluative judgment across domains: Liking balance, contour, symmetry and complexity in melodies and visual designs

Evaluative judgment-i.e., assessing to what degree a stimulus is liked or disliked-is a fundamental aspect of cognition, facilitating comparison and choosing among alternatives, deciding, and prioritizing actions. Neuroimaging studies have shown that evaluative judgment involves the projection of sensory information to the reward circuit. To investigate whether evaluative judgments are based on modality-specific or modality-general attributes, we compared the extent to which balance, contour, symmetry, and complexity affect liking responses in the auditory and visual modalities. We found no significant correlation for any of the four attributes across sensory modalities, except for contour. This suggests that evaluative judgments primarily rely on modality-specific sensory representations elaborated in the brain's sensory cortices and relayed to the reward circuit, rather than abstract modality-general representations. The individual traits art experience, openness to experience, and desire for aesthetics were associated with the extent to which design or compositional attributes influenced liking, but inconsistently across sensory modalities and attributes, also suggesting modality-specific influences.

Promoting vegetable intake in preschool children: Independent and combined effects of portion size and flavor enhancement

This study investigated the independent and combined effects on preschool children's vegetable intake of serving a larger portion of vegetables and enhancing their flavor. In a crossover design, lunch was served in childcare centers once a week for four weeks to 67 children aged 3-5 y (26 boys, 41 girls). The meal consisted of two familiar vegetables (broccoli and corn) served with fish sticks, rice, ketchup, applesauce, and milk. Across the four meals, we varied the portion of vegetables (60 or 120 g total weight, served as equal weights of broccoli and corn) and served them either plain or enhanced (6.6% light butter and 0.5% salt by weight). All meals were consumed ad libitum and were weighed to determine intake. Doubling the portion of vegetables led to greater consumption of both broccoli and corn (both p < 0.0001) and increased meal vegetable intake by 68% (mean ± SEM 21 ± 3 g). Enhancing vegetables with butter and salt, however, did not influence their intake (p = 0.13), nor did flavor enhancement modify the effect of portion size on intake (p = 0.10). Intake of other meal components did not change when the vegetable portion was doubled (p = 0.57); thus, for the entire meal, the increase in vegetable consumption led to a 5% increase in energy intake (13 ± 5 kcal; p = 0.02). Ratings indicated that children had similar liking for the plain and enhanced versions of each vegetable (both p > 0.31). All versions of vegetables were well-liked, as indicated by ≥ 76% of the children rating them as "yummy" or "just okay". Serving a larger portion of vegetables at a meal was an effective strategy to promote vegetable intake in children, but when well-liked vegetables were served, adding butter and salt was not necessary to increase consumption.

Cross-cultural emotional response to food stimuli: Influence of consumption context

Emotional responses elicited by certain types of food can be influenced by past experiences, frequency of consumption, culture, and other personal preferences. The present research aimed i) to investigate the impact of culture (Brazilian and Spaniard) on consumers' emotional responses and acceptability of different food stimuli, and ii) to explore the influence of evoked contexts. Brazilian (n = 437) and Spanish (n = 397) participants were exposed to three visual food stimuli (image of chocolate, potato chips, and yogurt) in an online survey and reported their emotional responses. Sociodemographic data, liking, and frequency of consumption were also collected. The evoked context in our study were designed and proposed, for each product and culture, based on four dimensions (consumption time, location, social setting, and hungry state). The evoked emotional lexicon was different for each food stimulus and was clearly influenced by the cultural factor. However, there are more similarities between cultures when evaluating the same product category. The evoked contexts were appropriated and influenced the citing frequency of some emotion terms, including positive ones. The most cited emotion terms tended to positively impact product liking ratings, acting as drivers of liking. Consumption level was positively related to liking regardless of cultural interactions for both chocolate and potato chips stimuli. In conclusion, the cultural background demonstrated to be an important impact factor to be considered for understanding the effects of product, consumption occasions, and degree of liking, on emotional responses to foods. These findings offer new possibilities to be explored in marketing messages for interventions or stimuli that guide food choices.

Understanding sweet-liking phenotypes and their implications for obesity: Narrative review and future directions

Building on a series of recent studies that challenge the universality of sweet liking, here we review the evidence for multiple sweet-liking phenotypes which strongly suggest, humans fall into three hedonic response patterns: extreme sweet likers (ESL), where liking increases with sweetness, moderate sweet likers (MSL), who like moderate but not intense sweetness, and sweet dislikers (SD), who show increasing aversion as sweetness increases. This review contrasts how these phenotypes differ in body size and composition, dietary intake and behavioural measures to test the widely held view that sweet liking may be a key driver of obesity. Apart from increased consumption of sugar-sweetened beverages in ESL, we found no clear evidence that sweet liking was associated with obesity and actually found some evidence that SD, rather than ESL, may have slightly higher body fat. We conclude that ESL may have heightened awareness of internal appetite cues that could protect against overconsumption and increased sensitivity to wider reward. We note many gaps in knowledge and the need for future studies to contrast these phenotypes in terms of genetics, neural processing of reward and broader measures of behaviour. There is also the need for more extensive longitudinal studies to determine the extent to which these phenotypes are modified by exposure to sweet stimuli in the context of the obesogenic environment.

Sensory-specific satiety, the variety effect and physical context: Does change of context during a meal enhance food intake?

Food variety has been shown to increase food intake, and sensory-specific satiety (a relative decrease in pleasantness of a food as it is consumed) has been proposed as the mechanism through which variety increases consumption. The aim of this study was to investigate whether variation of eating context can add to experienced meal variety and hence increase consumption even further. A total of 128 participants were assigned to one of four conditions in which they first ate a specific food item (ad libitum) until satiated, after which they consumed a second course ad libitum of either the same or a different food in either the same context or in a different context. We hypothesized that, compared to eating the same food in the same context during the second course, introducing a different food item or changing the context for the second course increases consumption (of the second course), and changing both food and context enhances food intake to a greater degree than only changing the food or changing the context. Results indicated that food variety (introducing a different food) significantly increased consumption in the second course, but that a context switch did not enhance consumption. These results suggest that there is little reason to believe that sensory-specific satiety is context specific.

Animal welfare information affects consumers' hedonic and emotional responses towards milk

This research aimed to explore the effects of animal welfare information on consumers' hedonic and emotional responses towards milk. Two studies were conducted. For Study 1, participants (N = 101) were asked to fill out a questionnaire on attitudes towards animal welfare, in which a variety of factors including raising methods, quality of life, emotions, quality of the product, nutrition, price, and environment, were tested. For Study 2, participants (N = 63) tasted a milk sample (2% fat, standardized and homogenized) in two different conditions: [1] blind (without any previous information), and [2] informed (with information stating that the milk was obtained from a farm with an animal welfare system in place). For Study 1, participants with higher milk consumption per week showed a higher agreement with positive animal welfare statements. For Study 2, the overall liking for the milk in the informed condition was significantly higher than that of the milk in the blind condition (7.4 vs. 6.8, using a 9-point hedonic scale). Participants had higher penalizations for the milk in the blind condition as they suggested that the milk's flavor, sweetness, aroma, and mouthfeel were not enough in the product. This research showed that animal welfare can be an important extrinsic factor in the consumers' hedonic and emotional responses towards milk. These findings can be useful for understanding consumers' behaviors towards animal welfare.

Some insights into the development of food and brand familiarity: The case of soy sauce in the Netherlands

With the increasing globalization, new unfamiliar flavors gradually find their way into local Western cuisines. The mechanisms behind the successful integration of novel flavors into local cuisines are largely unknown. This study investigates the effects of frequency of soy sauce use, levels of food neophobia, and brand specificity on liking of a relatively unknown flavor in the Netherlands, soy sauce. A total of eighty-nine (26 men and 63 women; mean age 47.5 ± 17.7 years) high- and low-frequency users of soy sauce rated liking of five soy sauces separately presented with and without branding information. Liking of four soy sauces with the typical salty and savory flavor increased with increasing frequency of use, and with decreasing levels of food neophobia. Another soy sauce with additives resulting in a distinctive taste was liked irrespective of the frequency of use. Soy sauces, which were recognized correctly or incorrectly as the participants' own familiar brand, received 50% higher or lower liking ratings than other soy sauces, respectively. Furthermore, users of one of the brands preferred the taste of their own brand over that of other brands, whereas users of the other brands did not show such specificity, indicating clear differences in specificity of liking soy sauce among the various user groups. This study provides insights into consumer liking and preference of semi-familiar foods, revealing the contribution of consumer traits and brand familiarity that may influence the spread of unfamiliar foods.

Preschoolers will drink their GREENS! Children accept, like, and drink novel smoothies containing dark green vegetables (DGVs)

Dark green vegetables (DGVs; e.g., spinach) are a nutrient rich source of essential vitamins and minerals; yet, children's intakes of DGVs fall well below dietary recommendations and creative solutions are needed. This study describes preschoolers (3-5 y) willingness to taste, liking, and intake of fruit-based smoothies containing DGVs (i.e., spinach, collards, kale), commonly referred to as "green smoothies," and explores individual differences in children's eating responses. Using a between-subjects design, preschoolers were randomized to either a FRUIT ONLY smoothie condition (n = 36) or FRUIT+DGV smoothie condition (n = 32). Children's acceptance and intake were collected in one tasting session and one ad libitum snack session, respectively. Parents reported on child food pickiness, food responsiveness, and approach, and children's intake of fruits and DGVs. Children self-reported on previous experience with the study fruits and DGVs. The initial tasting session revealed that the majority of children (84.3%) in the FRUIT+DGV condition willingly tasted all five green smoothies and rated the green smoothies as moderately liked (2.3 ± 0.1). Children in the FRUIT+DGV condition consumed 225.7 ± 31.4 g (9.0 ± 1.3 oz; 1.1 ± 0.2 cups; 91.9 ± 12.9 kcals) of their most preferred green smoothie, providing 18.3 ± 3.7 g (or 0.7 ± 0.1 cups) of DGVs. Children's willingness to try, liking, and intake did not differ by smoothie condition. Individual differences in children's intake are reported. In conclusion, children were willing to try fruit smoothies supplemented with DGVs. Children rated the green smoothies as moderately-liked and children's intake during snack met 31% of their weekly USDA recommendations for DGVs. Adding DGVs to fruit-based smoothies may compliment other effective feeding strategies for increasing children's vegetable consumption.

Reinforcing Value of a Moderately Physiologically Challenging Active Videogame Versus a Minimally Challenging Active Videogame

Objective: This study assessed the oxygen consumption [VO₂ mL/(kg·min)], liking, and relative reinforcing (motivating) value (RRV) of a moderately physiologically challenging exergame [Nintendo Wii-Sports Boxing (Boxing)] versus a minimally challenging exergame [Nintendo Wii Lego Star Wars (Lego)]. Materials and Methods: VO₂ and liking were recorded in children(N = 28, 7.8 ± 1.3 years old) during three 10-minute conditions: recumbent resting (Resting), and playing Wii Boxing or Wii Lego. Resting was completed first, and the order of exergames was randomized. Next, children performed an operant button pressing task using a progressive fixed ratio to assess the RRV of the two videogame conditions. Children worked to earn up to 11 minutes for Boxing, Lego, or a combination of the two. The output maximum (O_max) performed to earn access to each game was the measure of RRV. Results: There was a significant (P ≤ 0.03 for all conditions) step-wise increase in VO₂ from Resting [4.3 ± 1.2 mL/(kg·min)] to Lego [5.3 ± 0.5 mL/(kg·min)] and from Lego to Boxing [11.7 ± 4.2 mL/(kg·min)]. Liking was significantly greater for Boxing (P = 0.003) and Lego (P < 0.0001, 7.1 ± 2.9 cm; 7.1 ± 2.7 cm, respectively) versus Resting (4.6 ± 3.8 cm), with no significant difference between Boxing and Lego (P = 0.358). Lastly, O_max was significantly (P = 0.021) greater for Lego (257.7 ± 390.6 presses) than for Boxing (51.7 ± 131.0 presses). Conclusion: Oxygen consumption during Wii Boxing was significantly greater than during Wii Lego. Despite this greater physiological challenge, liking was similar for both Lego and Boxing. However, children were more motivated to play Lego than Boxing.

Pungency perception and liking for pasta filata cheeses in consumers from different Italian regions

We aimed to investigate whether the sensitivity to capsaicin had an effect on pungency perception of pasta filata cheeses. In addition, we assessed the effect of several individual variables (gender, age, consumer provenance, PROP status and personality traits) on both consumer liking and choice for pasta filata cheeses. Four pasta filata cheeses at two ripening times and 272 subjects from three different Italian locations were used. Based on sensory data, the PCA discriminated sweet (ripened at 2 months) from pungent cheeses (ripened at 12 months). Cheese pungency perception increased with increasing sensitivity to capsaicin (P < 0.001). There was no clear relationship between sensitivity to capsaicin or sensitivity to cheese pungency with cheese liking, whereas a number of other aspects, including sensory attributes and individual consumer characteristics, such as consumer provenance (P < 0.001), gender (P < 0.001) and food neophobia (P < 0.05), affected the liking for different pasta filata cheeses. Consumers who were younger (18-30 y.o.; P < 0.05), female (P < 0.001), unfamiliar with pungent foods (P < 0.0001) and consumers from Potenza (P = 0.001) more often declared to prefer sweet over pungent cheese, whereas in terms of real choice supertasters and neophobic subjects chose the sweet option more often (P = 0.01). In conclusion, sensitivity to capsaicin affected pungency perception in pasta filata cheese, whereas no clear relationship was observed between pungency perception and liking. The contribution of cheese and consumer characteristics on cheese liking and choice in addition to pungency, was confirmed by the differences in declared and real choice for sweet or pungent cheeses.

The effects of contexts on consumer emotions and acceptance of a domestic food and an unfamiliar ethnic food: a cross-cultural comparison between Chinese and Korean consumers

Contexts are known to affect hedonic and emotional responses to various food products. This study was conducted to investigate the effects of context on consumer acceptance and emotion of a domestic food and an unfamiliar ethnic food. Here, 97 Chinese and 83 Koreans rated hedonic and emotional responses to Korean shallot-seafood pancake (Haemul-pajeon) and Chinese shallot pancake (Cōngyóubĭng), in a sensory or ethnic context. Context did not significantly influence liking, but the Koreans' liking for Cōngyóubĭng significantly decreased in ethnic context compared to sensory context. Context significantly influenced eliciting positive emotions to domestic foods, whereas the context that increased positive emotions differed by the nationality of the panel. Ethnic food evaluated in ethnic context elicited emotions with negative valence or high arousal, whereas actual tasting significantly reduced these emotions. The results suggest that previous experiences and associations moderate the effect of context on emotions and acceptance.

Effects of a glucagon-like peptide-1 analog on appetitive and consummatory behavior for rewarding and aversive gustatory stimuli in rats

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is essential for the regulation of food intake and approved for the treatment of type 2 diabetes mellitus and obesity in humans. More recently, GLP-1 has been investigated for its ability to modulate motivation for food and drugs. Reward behavior can be divided into two components: 'motivational' (i.e., approach and consummatory behaviors) and 'affective' (i.e., perceived palatability). Studies show that GLP-1 analogs reduce the motivation to approach and consume palatable food, but the impact on affective responding is unknown. Thus, the present study tested the effect of the GLP-1 analog, Exendin-4 (Ex-4), on the appetitive response to intraorally delivered sucrose and quinine. Results showed that Ex-4 (2.4ug/kg ip) failed to alter passive drip, appetitive reactions (i.e., mouth movements, tongue protrusions, and lateral tongue protrusions) or aversive reactions (i.e., gapes) to sucrose. Paw-licking, however, was significantly reduced by Ex-4. Treatment with Ex-4 also failed to influence passive drip to quinine, but increased the latency to gape and reduced the total number of gapes emitted. In addition, Ex-4 reduced intake of quinine in water restricted rats, but did not reduce conditioned aversion (i.e., gapes) or avoidance (i.e., reduced intake) of a LiCl-paired saccharin cue. Thus, while Ex-4 had no effect on a learned aversion, it reduced approach and ingestion of sweet and bitter solutions, while leaving the appetitive affective response to the sweet almost intact, and the aversive affective response to the bitter reduced. Treatment with Ex-4, then, differentially modulates appetitive and consummatory components of reward, depending on the valence of the stimulus and whether its valence is learned or innate.

Hedonic contrast and the short-term stimulation of appetite

Hedonic contrast describes how liking for one item is influenced by the recent experience of other items which differ in hedonic valence. In the context of food stimuli, there is abundant evidence that hedonic contrast alters liking, but limited information on its impact on intake, and the aim here was to further clarify how hedonic impact modifies intake. Participants (96 female volunteers) rated and consumed ad libitum a sequence of four bowls of a snack (potato crisps) in one of three conditions. In the Palatable (salted crisps) and Bland (unsalted crisps) conditions, all four bowls were the same. In the Contrast condition participants alternated between salted and unsalted crisps. In total, significantly more was consumed in the Palatable (35.0 ± 2.6 g) than Bland (26.6 ± 2.4 g) condition, but most was consumed in the Contrast condition (37.0 ± 1.6 g). The impact of hedonic contrast was seen in the third serving, where those in the Contrast condition consumed the most of any serving, and significantly more than in Palatable or Bland conditions, and at the final serving, when those in the Contrast condition consumed significantly less than in Bland or Palatable conditions. Rated liking for the foods showed a similar pattern, with liking decreasing across servings in Palatable and Bland conditions. However, liking was influenced by the preceding serving in the Contrast condition, and the change in liking produced by contrast predicted subsequent intake. Overall, these data provide clear evidence that hedonic contrast can influence consumption, with intake driven by this adjusted liking.

Impact of 'free-from' and 'healthy choice' labeled versions of chocolate and coffee on temporal profile (multiple-intake TDS) and liking

Product reformulation for obtaining "free-from" or "healthy choice" versions may confer significant changes in sensory characteristics which could not meet consumer expectations in terms of sensory perception. Therefore, this paper aims to evaluate the influence of formulations of different product categories on their dynamic sensory profile and consumer acceptability. A sensory panel of 23 semi-trained assessors evaluated two product categories, chocolate and milk coffee, using Temporal Dominance of Sensations (TDS) over three consecutive intakes/sips (multiple-intake TDS) on two replications. TDS allowed us to describe the dynamic profile of classic products over the three intakes and to identify differences in the sensory temporal profile compared to their 'healthier choice' reformulated versions. For the chocolate category, increasing the cocoa and the reduction of lactose content mainly influenced the dominance of sweetness, dairy, cocoa, crunchy and bitterness attributes. No sugar addition and absence of caffeine (decaffeinated version) in ready to drink milk coffee beverage modified temporal perception of sweetness, bitterness, coffee flavor and smoothness texture. Higher overall liking averages were associated with the dominant attributes of chocolate with a higher level of cacao and milk coffee decaffeinated. The obtained results of the present work suggest that the multiple-intake TDS technique can be applied for the evaluation of different food categories, helping to develop healthier products and predicting the liking.

The affective priming paradigm as an indirect measure of food attitudes and related choice behaviour

In this Registered Report, we assessed the utility of the affective priming paradigm (APP) as an indirect measure of food attitudes and related choice behaviour in two separate cohorts. Participants undertook a speeded evaluative categorization task in which target words were preceded by food primes that differed in terms of affective congruence with the target, explicit liking (most liked or least liked), and healthiness (healthy or unhealthy). Non-food priming effects were tested as a manipulation check, and the relationship between food priming effects and impulsive choice behaviour was also investigated using a binary food choice task. As predicted, priming effects were observed for both healthy and unhealthy foods, but there was no difference in the magnitude of these effects. This may suggest that the paradigm is most sensitive to affective, but not cognitive, components of attitudes (i.e., healthiness), but alternative theoretical explanations and implications of this finding are discussed. Food and non-food priming effects were observed in both reaction time (RT) and error rate (ER) data, but contrary to expectations, we found no association between food RT priming effects and choice behaviour. All findings from confirmatory analyses regarding RT and ER priming effects, and the absence of the expected correlations between priming effects and impulsive food choices, were successfully replicated in the online cohort of participants. Overall, this study confirms the robustness of the APP as an indirect measure of food liking and raises questions about its applied value for research of eating behaviours.

Image database of Japanese food samples with nutrition information

Background

Visual processing of food plays an important role in controlling eating behaviors. Several studies have developed image databases of food to investigate visual food processing. However, few databases include non-Western foods and objective nutrition information on the foods.

Methods

We developed an image database of Japanese food samples that has detailed nutrition information, including calorie, carbohydrate, fat and protein contents. To validate the database, we presented the images, together with Western food images selected from an existing database and had Japanese participants rate their affective (valence, arousal, liking and wanting) and cognitive (naturalness, recognizability and familiarity) appraisals and estimates of nutrition.

Results

The results showed that all affective and cognitive appraisals (except arousal) of the Japanese food images were higher than those of Western food. Correlational analyses found positive associations between the objective nutrition information and subjective estimates of the nutrition information, and between the objective calorie/fat content and affective appraisals.

Conclusions

These data suggest that by using our image database, researchers can investigate the visual processing of Japanese food and the relationships between objective nutrition information and the psychological/neural processing of food.

Associations between sweet taste function, oral complex carbohydrate sensitivity, liking and consumption of ad libitum sweet and non-sweet carbohydrate milkshakes among female adults

Excess energy intake is recognised as a strong contributing factor to the global rise of being overweight and obese. The aim of this paper was to investigate if oral sensitivity to complex carbohydrate relates to ad libitum consumption of complex carbohydrate foods in a sample group of female adults. Participants' ((n 51 females): age 23·0 (sd 0·6) years (range 20·0-41·0 years); excluding restrained eaters) sensitivity towards maltodextrin (oral complex carbohydrate) and glucose (sweet taste) was assessed by measuring detection threshold (DT) and suprathreshold intensity perception (ST). A crossover design was used to assess consumption of two different iso-energetic preload milkshakes and ad libitum milkshakes - (1) glucose-based milkshake, (2) maltodextrin-based milkshake. Ad libitum intake (primary outcome) and eating rate, liking, hunger, fullness and prospective consumption ratings were measured. Participants who were more sensitive towards complex carbohydrate (maltodextrin DT) consumed significantly more maltodextrin-based milkshake in comparison with less-sensitive participants (P = 0·01) and this was independent of liking. Participants who had higher liking for glucose-based milkshake consumed significantly more glucose-based milkshake in comparison with participants with lower hedonic ratings (P = 0·049). The results provide support regarding the role of the oral system sensitivity (potentially taste) to complex carbohydrate and the prospective to overconsume complex carbohydrate-based milkshake in a single sitting.

Children's liking and wanting of foods vary over multiple bites/sips of consumption: A case study of foods containing wild blueberry powder in the amounts targeted to deliver bioactive phytonutrients for children

To encourage children to frequently consume wild blueberries as part of their dietary patterns, incorporating blueberry powder into specific foods may be an effective strategy. Thus, it is important to determine appropriate types of food products that both minimize food processing-induced loss of beneficial components of blueberries (e.g., anthocyanins) and satisfy at the same time both nutritional and sensory aspects. For clinical studies assessing the health benefits of blueberry-containing food samples, it would be important to ensure children consume the entire portion of the test samples. This study, therefore, aimed at determining how sensory acceptability (liking) and psychological reward (wanting) of wild blueberry-based foods vary over multiple steps of ad libitum consumption: appearance, first bite/sip, half bite/sip, and full consumption. Five different types of foods containing the targeted amount of wild blueberry powder were prepared for sensory testing (oatmeal bar, beverage, ice pop, gummy, and cookie), and the residual amounts of total anthocyanin and chlorogenic acid were measured to confirm levels targeted to deliver bioactive amounts of these phytochemicals. Results showed that while overall liking and desire to eat did not differ among the five samples at the appearance and first bite/sip steps, they differed significantly at the end of consumption. Although children liked and wanted to consume the cookies more when compared to beverages, ice pops, and/or gummies, total anthocyanin contents were lower in cookies and gummies than in wild blueberry powder, beverage, and ice pop samples. Notably, the oatmeal bars with significant amounts of total anthocyanin and chlorogenic acid did not significantly differ from the cookies with respect to overall liking, desire to eat, and the amount consumed. In conclusion, this study shows that sensory evaluation using multiple bites/sips of ad libitum food consumption, along with a measurement of beneficial compounds, is efficient in determining appropriate vehicles for clinical studies of wild blueberry-containing foods.

Minimal effect of evoked contexts in product testing with consumers: Case studies using typical consumption situations

Consumer studies conducted under central location test (CLT) conditions continue to be dominant in product research and context evocation have been suggested as an avenue to partly mitigate the lack of real consumption settings. In this research the influence of evoked context on product acceptability was investigated in eight diverse consumer studies (138-268 participants per study) through the use of between-subjects designs that allowed the comparison of hedonic scores obtained with and without evoked context. In a departure from previous research, consumers mentally evoked their typical consumption contexts for the focal product categories and content analysis of descriptions of these situations showed them to often be idiosyncratic. Results were partly product- and situation-specific, and in this regard replicated past research. The evoked context only significantly modified hedonic scores in two of the eight studies, whereas it increased sample discrimination in three studies. Thus, accumulating evidence now supports the conclusion that evoked context is less rather than more likely to impact hedonic responses. Nonetheless, a benefit of context evocation is to give products a more complete meaning, and this may motivate their continued use in CLT settings. For researchers who wish to continue their use, key considerations in implementation are discussed, including relevance in home-use testing (HUT). By asking consumers to describe a typical eating occasion for the tested products, useful understanding of product use and pairings is gained. Such data can be easily elicited from consumers and obtained independently of context evocation.

Dissociating wanting and anticipated liking from consummatory liking in smokers with different levels of nicotine dependence

INTRODUCTION

Incentive Sensitisation theory suggests wanting and liking are dissociable concepts, with wanting, but not liking typically increasing with repeated drug use. Wanting is associated with anticipation of reward, whereas liking relates to pleasure derived from consummatory behaviour. However, numerous studies have conceptualised liking as an anticipatory cognition. This study explores whether levels of nicotine dependence differentially effect wanting and liking responses to smoking-related cues, and whether anticipated and consummatory liking are equivalent, and dissociable from wanting.

METHOD

Heavy (HS, mean = 16 cigarettes/day) and light non-daily (LS, mean = 2 cigarettes/day) smokers completed wanting and anticipated liking questionnaires pre-, immediately post-exposure to smoking-related and neutral cues and at session-end. Consummatory liking was measured post-session, immediately after smoking.

RESULTS

Wanting and anticipated liking responses were comparable. Smoking-related cues increased wanting and anticipated liking compared to neutral cues. This effect was maintained until session-end. No baseline differences were seen between HS and LS on wanting or anticipated liking, however after cue exposure, and at session-end, HS reported greater drug wanting and anticipated liking than LS. Conversely, HS and LS did not differ on consummatory liking. Analyses confirmed the relationship between wanting and anticipated liking was significantly stronger than wanting and consummatory liking or anticipated and consummatory liking.

CONCLUSIONS

Wanting and anticipated liking appear to be overlapping constructs assessing expectations of reward, that are dissociable from consummatory liking. Furthermore, heavier smoking increases drug wanting, but not smoking pleasure. Future attempts to dissociate these concepts should ensure liking is measured during/immediately after consumption.