Temporal dominance of sensations, emotions, and temporal liking measured in a bar for two similar wines using a multi-sip approach

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

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

Identifying temporal sensory drivers of liking of biscuit supplemented with brewer's spent grain for young consumers

Brewer's spent grain (BSG), a by-product of the brewing industry, has great potential as food additive. BSG is particularly rich in protein and fibre content which makes it an ideal nutritional fortifier for biscuits. However, adding BSG to biscuits can lead to changes in sensory perception and consumer acceptance. This study explored the temporal sensory profiles and drivers/inhibitors of liking in BSG-fortified biscuits. Six biscuit formulations were obtained from a design with factors oat flake particle size (three levels: 0.5 mm, small commercial flakes, large commercial flakes) and baking powder (two levels: with, without). Consumers (n = 104) tasted the samples, described their dynamic sensory perception using the Temporal Check-All-That-Apply (TCATA) method, and rated their liking on a 7-point categorical scale. The Clustering around Latent Variables (CLV) approach was used to group consumers into two clusters based on their preferences. The temporal sensory profiles and drivers/inhibitors of liking were investigated within each cluster. Foamy and Easy-to-swallow were sensory drivers of liking for both groups of consumers. However, inhibitors of liking were different in the two clusters: Dense and Hard-to-swallow for one cluster and Chewy, Hard-to-swallow and Hard for the other cluster. These findings give evidence that manipulating oat particle size and presence/absence of baking powder changes BSG-fortified biscuits' sensory profiles and consumer preferences. A complementary analysis of the area-under-curve of the TCATA data and inspection of individual temporal curves showed the dynamics of perception and showed how oat particle size and presence/absence of baking powder affected consumer perception and acceptance of BSG-fortified biscuits. The methods proposed in this paper can be further applied to understand how enriching products with ingredients that would otherwise go to waste affects acceptance in different consumer segments.

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

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

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

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

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

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

Temporal Sensory Profiles of Regular and Sodium-Reduced Foods Elicited by Temporal Dominance of Sensations (TDS) and Temporal Check-All-That-Apply (TCATA)

Temporal sensory methods can be used to highlight the impact of sodium reduction on the dynamic sensory profile of foods targeted for sodium reduction. Study aims were to compare the temporal sensory attribute profiles of regular and sodium-reduced food products elicited by TDS and TCATA, over single and multiple oral intakes. A total of 20 semi-trained participants evaluated commercially available regular and sodium-reduced canned corn, cooked ham (single intakes), potato chips and cream of mushroom soup (5 intakes) using both TDS and TCATA. Regular and sodium-reduced products differed in not only salty but also other sensory attributes, noticeably dry for chips, sweet for corn, bitter and metallic for ham, thick, creamy, sweet, and starchy for soup. TDS and TCATA provided comparable information for the key sensory attributes characterizing and differentiating the regular and sodium-reduced products. TDS profiled significant differences between samples for a larger number of attributes than TCATA, while TCATA profiles were more consistent across intakes. Multiple intakes changed the duration of attribute dominance but not the number of significantly dominant attributes in TDS profiles. The current findings provide insight for applications of temporal profiling to other food products and development of sodium-reduced foods with attribute profiles acceptable to consumers.

Exploring young consumers' attitudes and emotions to sensory and physicochemical properties of different red wines

To gain deeper understanding on young consumers' attitudes and preferences to wines is needed to connect wine industry with the youth. The aims of the present study were (i) to define 'trendy wine' for young consumers and (ii) to identify chemical drivers of liking in red wines for the youth. The study was divided in two phases: phase I explored young consumers' attitudes towards wines using an online survey, and phase II studied the relationship between hedonic and emotional responses elicited by 12 red wine samples and their physico-chemical characteristics. Consumers' responses and physico-chemical data were related using Principal Component Analysis (PCA). Results of the online survey showed that trendy wines were associated to: sparkling, soft, fresh, fruity, sweet, light, and balanced wines. Also, young consumers reported that, although flavor was considered the most important attribute, price and Protected Designation of Origin could be valuable attributes. PCA results of phase II showed that wines with a lower ratio [total polyphenol index/polysaccharides] were more liked and elicited more positive emotions than wines with higher total polyphenol index, color intensity, volatile acidity, and alcohol content. Liking and positive emotions were positively related to higher Odor Activity Values of the volatile compounds from the organic acids group. The presence of benzenoids and lactones, and the lower presence of terpenoids & norisoprenoids were associated with negative emotions. In conclusion, red wines should be soft (described as lower ratio [total polyphenol index/polysaccharides]), and have floral, and fruity aromas to better connect with young consumers.

Rescuing Flavor Identity and Dynamic Perception in Puréed Dishes; A Restructuring Solution for the Purée Diet

With age, difficulties with masticating and swallowing means food consistency and structure must be modified, such as puréeing food. However, elderly consumers have reported that puréed food’s taste lacks appeal. This study shows how puréeing food changes the recognition and dynamics of flavors and new strategies to improve them. Further, to measure the identification and dynamics of flavor, a new sensory method was investigated that combined Free Choice and Temporal Order of Sensation (Free-TOS). Three dishes (macaroni, pizza, and potato salad), their purées, and three pasta purées with added flavors (cheese and dry-cured ham; added directly or as an oil in water emulsion or using two types of emulsions (oil in water and water in oil) were assessed by three groups of 60 consumers using Free-TOS. Results showed that in the purée the frequency of mentioned sensations decreased compared with the dish, as it was more difficult to identify flavors. Adding flavors in powder form only allowed a cheese/ham flavor identification, but in the purées with emulsions, it was possible to identify the dry-cured ham flavor. Therefore, this study showed that the Free-TOS method does not need a predetermined attribute list and registers the actual identified flavors and their order of appearance.

Does the indoor thermal environment influence the dominant sensation in a functional beverage attribute?

Different thermal environments can affect human productivity with repercussions on cognitive ability and physiological changes. However, the direct effect of room temperature on the sensations of food in the mouth during consumption is not yet well established. This study aimed to investigate the effect of indoor temperature on dominant sensations during intake of a beverage containing non-nutritive sweeteners. The temporal dominance of sensations (TDS) technique was used to evaluate seven functional beverages with different non-nutritive sweeteners. Sixty consumers participated in the test, attending 3 days of laboratory analysis with strictly controlled indoor temperatures (20, 24, and 26 °C). The indoor temperature affected the TDS curves of four functional beverages, with emphasis on the colder environment, which accentuated the sensation of bitter taste in the samples sweetened with stevia and neohesperidin. In the warmer environment, a TDS peak of fruit flavor was observed for the sucrose-sweetened sample, while the neotame-sweetened sample presented lower dominance rate for sweetness. The sensory performance of the samples sweetened with non-nutritive sweeteners, determined by the dominance rate of attributes, can change over time in different indoor temperatures. PRACTICAL APPLICATION: Cold and warm environments can affect the consumer's decision to buy beverages, but the effect of the indoor temperature on the taste sensation of beverages has not been elucidated. The objective of this research was to evaluate whether the indoor temperature can affect the dominance of sensations during the consumption of a low-calorie beverage. The results showed that the cold environment prolonged the sensation of bitter taste in the beverages sweetened with natural sweeteners, which can help the nonalcoholic beverage industry to choose another type of sweetener, considering a new product sensory influence facto: room temperature.

Current Research Related to Wine Sensory Perception Since 2010

Due to socioeconomic changes, the demand for and interest in alcoholic beverages have recently been increasing. Among various alcoholic drinks, consumer preference for wine could be varied. It might be related with its complexity, as wine is known to have characteristics that are difficult to understand. Several factors, such as intrinsic or extrinsic factors interact to influence wine complexity and consumer perception. Many studies have been conducted to understand the complexity of wine, allowing deeper insight into its perception by consumers. Studies over the last decade on wine sensory perception using descriptive analysis and consumer tests were reviewed. Additionally, chemical analysis studies were included because flavor constituents information would contribute to a better understanding of sensory perception. Descriptive sensory analysis of wine was reviewed considering panels and flavor characterization for better understanding wine-related research. Several consumer studies regarding liking/preference, emotion, context, and extrinsic factors to understand consumer preference or perception were reviewed. Research on chemical constituents may affect consumer perception and is thus presented in this review. However, most of the research was focused on a narrow range of wine, thus is missing overall wine category evaluations. Furthermore, evaluations were mainly in wine-producing countries, resulting in limited understanding of an emergent market. This review will help guide wine researchers and industry by providing information on factors influencing consumer wine perception.