Diet and odor hedonic ratings: comparative study between vegetarians, flexitarians, and omnivores.

OBJECTIVES: Odor hedonic perception is well known to exhibit great variability and to depend on several parameters, i.e. stimulus, context, and subject characteristics. As hedonic perception (pleasant/unpleasant character) of food odors is considered one of the most prominent dimensions in eating behavior, the question of hedonic variability in this context arises. Thus, the aim of the present study was to compare odor hedonic ratings in three populations with regard to diet (i.e. omnivore, vegetarian, and flexitarian diets). METHODS: Four categories of odors were compared: meat, vegetable, other food, and non-food odors. RESULTS: The results showed that vegetarian and flexitarian individuals rated meat odors as more unpleasant than omnivores, while no significant difference was found for other categories of odors. DISCUSSION: The question of whether the diet influences the hedonic perception or/and inversely is discussed, regarding several aspects of food consumption such as eating disorders, food education, … and could further serve to manage eating behaviors. PRACTICAL APPLICATIONS: This study evidenced that vegetarians and flexitarians specifically rated meat odors as being more unpleasant than those of omnivores. Because of the growing number of vegetarians and flexitarians in the general population, it could be suggested to take into account the odor hedonic perception (especially regarding food odors) in studies related to diets. Besides, the present results could further serve research in several aspects of food consumption such as eating disorders (anorexia, bulimia … etc.) or food education as well as the management of eating behaviors, especially in an elderly population.

Personality traits affect the influences of intensity perception and emotional responses on hedonic rating and preference rank toward basic taste solutions.

This study aimed at determining, based on independent predictors of taste intensity and emotional response, whether individual personality traits could affect prediction models of overall liking and preference rank toward basic taste solutions. Sixty-seven participants rated taste intensities (TI) of four basic-taste solutions at both low and high concentrations, and of plain water. Emotional responses toward each sample were measured using a self-reported emotion questionnaire (SE), facial expressions (FE), and/or autonomic nervous system responses (ANS). Participants rated overall liking of the samples and ranked their preferences. Based on the results of a hierarchical cluster analysis of five personality traits measured using the Big Five Inventory, participants were classified into two clusters: cluster N (high neuroticism) and cluster E (high extraversion). Results showed that the SE measure for both clusters N and E was better than the TI, FE, and ANS measures in explaining variances of overall liking or preference rank. A measurement of effect size found that using FE and/or taste intensity measures, along with self-reported emotion measure, could enhance model predictability of overall liking or preference rank toward taste samples for cluster N, while the contribution to the prediction model for cluster E was minimal. ANS measures showed little contribution to the prediction model of overall liking for either cluster. In conclusion, this study shows that personality traits, in particular traits of extraversion and neuroticism, affect not only optimum measures of emotional responses, but also modulate predicting overall liking and preference rank toward basic taste solutions.

Cross-Cultural Differences between Italian and UK Consumer Preferences for 'Big Top' Nectarines in Relation to Cold Storage.

Nectarines are perishable fruits grown in Southern Europe, valued for their sensorial properties. Chilling is used in the supply chain for Northern European consumers, while Southern European consumers can access fresh, locally grown fruit or cold-stored supermarket fruit. Cold storage and fruit ripening affect texture and flavour. Here a consumer survey and hedonic testing compared the appreciation of nectarines (cv. Big Top) in Italy and at two UK sites (n = 359). Fruit was at the commercial harvest stage, or stored at 1 °C or 5 °C for seven days, then sampled after two days' (Italy and one UK site) or four days' (second UK site) ambient recovery. In the consumer survey, the most important factors involved in purchase decision were ripeness, texture, colour, taste and price. Named varieties were more important to Italian than UK respondents, whilst ripeness, price, taste, blemishes, aroma, and 'best before date' were more important in the UK. In sensory analyses, fruits at the commercial harvest stage were preferred to those stored at 1 °C. Preference for the 5 °C stored peaches depended on recovery time. Distinct clusters of peach sensorial attributes were positively or negatively linked to hedonic rating. Factors important in purchase decisions did not affect hedonic rating in the tasting.

Sensory Traits and Consumer's Perceived Quality of Traditional and Modern Fresh Market Tomato Varieties: A Study in Three European Countries.

Consumer dissatisfaction with the flavor quality of many modern fresh market tomato varieties has fostered breeders' interest in sensory quality improvement, and the demand for traditional varieties, which are generally associated with better flavor. To achieve further knowledge on the factors influencing the sensory quality and consumers' preferences and perception, European traditional and modern fresh market tomato varieties were grown and evaluated in France, Italy, and Spain. Different growing conditions were tested in France (soilless vs. soil) and in Spain (open field vs. greenhouse), while in Italy fruits were evaluated at two ripening stages. Fruit quality was assessed by integrating physicochemical analyses, sensory profiles, and consumer tests. In all three countries, overall modern varieties were perceived as having more intense "tomato flavor" and "overall flavor" than traditional ones. In France and Spain, consumers' preferences were more oriented towards modern varieties than traditional ones. Significant growing condition effects were found on sensory and physicochemical traits, while the effect on consumers' overall liking was not significant, largely depending on the genotype. A fair agreement between product configurations from descriptive analysis by trained assessors and Check-All-That-Apply (CATA) questions by consumers was observed. Penalty-lift analysis based on CATA allowed identifying positive and negative drivers of liking.

Development of a direct mapping model between hedonic rating and facial responses by dynamic facial expression representation.

Consumer tests are one of the most important activities in product development. More evidence indicates that consumer emotions in real life are mostly driven by unconscious mechanisms, and implicit measurements are regarded as beneficial by an increasing number of sensory and consumer scientists. Nonverbal manner such as facial expression analysis is a supplement to the declarative method and brings very insightful results. Up until now, the facial expression analysis for consumers' acceptance identification is limited to investigate the relationship between hedonic rating and facial expression descriptors, such as facial coding system (FACS or MAX), discrete facial expressions (i.e. happiness, sadness, surprise, fear, anger, and disgust), and affective dimensional model (valence and activation). In this study, we attempt to develop a direct mapping model between the hedonic rating and facial responses evoked by various taste stimuli. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with six levels, and five types of juice are used as stimuli. Firstly, the hedonic rating categories are defined based on the nine-point hedonic scale, with a coarse-to-fine division of scale levels based on two directions of like and dislike. Secondly, the facial dynamic optical flow method is employed to analyze facial characteristics of the subjects' facial responses evoked by taste stimuli. And the genetic algorithm is conducted to select facial regions that have high contribution to hedonic rating identification. It indicates that the texture changes of eye area, wrinkles at the nasal root, and mouth area can effectively reflect the facial reaction corresponding to hedonic rating. The research shows that it is feasible to establish a direct mapping model between hedonic rating and facial responses. The hedonic rating can be predicted through automatic facial reading technology, without extra transformation from predefined emotional models. In general, this is the first try to discuss the direct prediction of hedonic rating through facial expressions up to now, and it is a complex problem due to various influence factors.

Multivariate relationships among sensory attributes and volatile components in commercial dry porcini mushrooms (Boletus edulis).

The present research investigated the relationships among sensory attributes and volatile components in dry porcini mushrooms by multivariate statistical analyses. The sensory characteristics were based on quantitative descriptive analysis and consumer hedonic assessment. The volatile compounds were extracted by solid-phase microextraction, then were identified using gas chromatography-mass spectrometry and gas chromatography-olfactometry. The results showed that the high hedonic rating of porcini mushrooms was due in part to its aroma notes such as seasoning-like, roasted, cacao-like and smoky. High hedonic liking and positive aromas of porcini mushrooms could be responsible for the volatiles including 3-(methylthio)propanal, 3-(methylthio)propanol, pyrazines, phenolic and furanone components. On the other hand, raw mushroom-like, cardboard-like, as well as sweaty attributes were attributed to the relatively low hedonic liking of porcini mushrooms, which correlated with high contents of 1-octen-3-ol, octanal, 2-pentylfuran and 3-methylbutanoic acid. The information reported here could be important for the quality control of commercial porcini mushrooms by providing an approach to strengthen the interpretation of sensory data by showing how they were affected by the chemical properties.

Differences in short-term food preferences following vertical sleeve gastrectomy and Roux-en-Y gastric bypass surgery.

Bariatric surgery is effective in reducing body weight and obesity-related comorbidities. This study examined differences in the short-term effect of Roux en Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) on the hedonic rating of food. Predominantly black women with complicated obesity and a BMI>50 g/m(2) completed a validated food preference questionnaire before and 1-3 months following surgery. Analysis of preference scores indicated that the preference for fat decreased with both surgeries. VSG also decreased the preference for sugar. Further studies are needed to evaluate long term effects of surgery on food preferences and to elucidate physiological mechanisms.

Systematic comparison of hedonic ranking and rating methods demonstrates few practical differences.

Hedonic ranking is one of the commonly used methods to evaluate consumer preferences. Some authors suggest that it is the best methodology for discriminating among products, while others recommend hedonic rating. These mixed findings suggest the statistical outcome(s) are dependent on the experimental conditions or a user's expectation of "what is" and "what is not" desirable for evaluating consumer preferences. Therefore, sensory and industry professionals may be uncertain or confused regarding the appropriate application of hedonic tests. This paper would like to put this controversy to rest, by evaluating 3 data sets (3 yogurts, 79 consumers; 6 yogurts, 109 consumers; 4 apple cultivars, 70 consumers) collected using the same consumers and by calculating nontied ranks from hedonic scores. Consumer responses were evaluated by comparing bivariate associations between the methods (nontied ranks, tied ranks, hedonic rating scores) using trellis displays, determining the number of consumers with discrepancies in their responses between the methods, and comparing mean values using conventional statistical analyses. Spearman's rank correlations (0.33-0.84) revealed significant differences between the methods for all products, whether or not means separation tests differentiated the products. The work illustrated the inherent biases associated with hedonic ranking and recommended alternate hedonic methodologies.