Temporal dominance of sensations (TDS) panel behavior: A preliminary study with chocolate

Temporal dominance of Sensations: Do different concepts of "dominance" affect the results?

The purpose of this study was to understand the role of "dominance" definitions in the results of TDS applied to consumers. This study compared two temporal dominance of sensations (TDS) approaches - TDS-I - that attracts the most attention and TDS-II - most intense/strongest sensation - in the context of evaluating artisanal Minas cheeses from the Serra da Canastra and chocolate with different cocoa concentrations samples. TDS curves were constructed and a trajectory-based principal component analysis (PCA) was performed dominance rates at ten equally spaced time points. Additionally, difference curves, multiple factor analysis (MFA) and regression vector coefficient (RV coefficient) were performed to compare the two approaches. The findings showed that the two approaches produced similar results, suggesting that consumers interpret the terms dominant and intense in a similar way during TDS evaluations, the results were even closer at the chocolate study than at the cheese study. However, in both approaches were observed low dominance rates and differences between the sensation perception time, mainly in the evaluation of cheese flavor. This variability may be attributed to the complexity of the cheese's flavor and the varied interpretations of dominance among evaluators. Despite these differences, the approaches showed similar characterizations across the same samples, demonstrating high reproducibility and a strong ability to differentiate between samples. This study demonstrates that the choice between the terms dominant (which captures more attention) or intense (stronger) to guide consumers in performing the sensory test does not significantly influence the results. Consequently, it is possible to adopt greater freedom and flexibility in the terminology used to instruct participants in conducting the test.

Phenolic composition and sensory dynamic profile of chocolate samples enriched with red wine and blueberry powders

Cabernet Sauvignon (CS) and a combination of Cabernet Sauvignon with blueberry extract (CS + B), were spray dried (using maltodextrin DE10, 13.5% w/w as a carrier) to obtain two types of phenolic-rich powders. The addition of blueberry to CS increased phenolic compounds content by 16%. Eight chocolate formulations were obtained by modifying concentrations of cocoa solids, cocoa butter, and sugar. Six of the samples were added with 10% w/w of phenolic-rich powder, while two of them remained as powder-free controls. The anthocyanin and flavan-3-ol profiles of chocolates were determined by HPLC-DAD-MS and HPLC-MS, respectively. In addition, the sensory dynamic profile of samples was assessed by Temporal Dominance of Sensations with a consumer panel. Results showed that the addition of phenolic-rich powders produced a significant increase in the anthocyanin composition obtaining the highest anthocyanin content in the white chocolate added with CS + B powder. On the other hand, adding 10% of CS powder to dark chocolate (55% cocoa pellets) did not result in a significant increase in phenolic compounds. The addition of phenolic-rich powders to chocolates influenced visual color, texture, and taste, leading to new products with distinctive characteristics and increasing the possibility of using phenolic-rich powders as innovative and healthy ingredients.

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.

Impact of using cocoa bean shell powder as a substitute for wheat flour on some of chocolate cake properties

The cocoa bean shell is a residue rich in bioactive compounds and its use as an ingredient in the food industry has been studied. This work had the objective of proposing the elaboration of chocolate cake with substitution of wheat flour by cocoa bean shell powder (CSp). Five formulations with different percentages of CSp were used: 25%, 50%, 75%, 100% and 0% (control). The cakes were evaluated by technological characteristics (volume, texture profile, firmness and colour), antioxidant profile (DPPH, β-carotene/linoleic acid system, phenolic compounds, anthocyanins and tannins) and sensory tests (TDS and acceptance). The technological characteristics and antioxidant activity of the cakes were influenced by the different concentrations of CSp compared to the control sample. The cakes containing up to 75% CSp presented satisfactory sensory acceptance. Therefore, CSp has been revealed to be a prominent alternative substitute ingredient to be used promisingly in the food industry.

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

Abstract

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

Practical Application

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

Bootstrap Resampling of Temporal Dominance of Sensations Curves to Compute Uncertainties

In the last decade, temporal dominance of sensations (TDS) methods have proven to be potent approaches in the field of food sciences. Accordingly, thus far, methods for analyzing TDS curves, which are the major outputs of TDS methods, have been developed. This study proposes a method of bootstrap resampling for TDS tasks. The proposed method enables the production of random TDS curves to estimate the uncertainties, that is, the 95% confidence interval and standard error of the curves. Based on Monte Carlo simulation studies, the estimated uncertainties are considered valid and match those estimated by approximated normal distributions with the number of independent TDS tasks or samples being 50-100 or greater. The proposed resampling method enables researchers to apply statistical analyses and machine-learning approaches that require a large sample size of TDS curves.

Understanding stickiness in sugar-rich food systems: A review of mechanisms, analyses, and solutions of adhesion

Stickinessis an inherent textural property in many sugar-rich foods, which can be problematic to the processing of confectionery products. The adhesion between foods and contact surfaces during processing and consumption has not been well understood in academia or industry. The theories of adhesion were discovered by scientists in the adhesive field of study, some of which can explain the stickiness phenomenon of confections. This work reviewed these theories in the context of sugar-rich foods, followed by a survey on the sensory and instrumental analyses of stickiness. Furthermore, the contributions of ingredients, temperature, compression, and contact surfaces to sugar-rich food adhesion are highlighted.

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.

Temporal Sensory Perceptions of Sugar-Reduced 3D Printed Chocolates

Sugar-reduced chocolates with desirable sensory qualities and sweetness can be created using a 3D printer by layering chocolates with different sugar concentrations. This study aimed to evaluate the temporal sensory profile, perceived sweetness intensity, and acceptance of prototype sugar-reduced and non-sugar-reduced 3D printed chocolates. A consumer panel (n = 72) evaluated the sensory profiles of six-layered chocolates. Sensory profiles were determined by temporal dominance of sensations (TDS), overall sweetness by a five-point intensity scale, overall liking by the nine-point hedonic scale, and differences among chocolates over time were visualized by principal component analysis (PCA). Layering by 3D printing achieved a 19% reduction in sugar without changes in the perceived overall sweetness and overall liking. Layering order of high and low sugar chocolate influenced the perceived overall sweetness and temporal sensory profiles of 3D printed chocolates with different total sugar concentrations. The dominance of attributes associated with milk chocolate was observed to increase sweetness perception while the dominance of attributes associated with dark chocolate was observed to decrease overall sweetness perception. Three-dimensional food printing technology is progressing rapidly, and further sugar reduction could be achieved with refined research methods.

Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS)

Pungency is increasingly being recognized as an important factor of overall sensory quality, palatability, and consumer preference of distilled spirits. The characterization of pungency is necessary to evaluate the potential sensory quality of distilled spirits. In this study, the temporal profiles of pungency of Baijiu with different aging times were evaluated using time-intensity (TI) and temporal dominance of sensations (TDS) methods, considering both pungency intensity and pungency sub-qualities. TI results indicated significant differences in release rate of pungency during Baijiu consumption. Compared to young Baijiu, old Baijiu tend to show higher release rate of pungency, the areas under the curve and duration of pungency were significantly decreased in old Baijiu. The TDS results showed significant differences in the combination of dominant sub-qualities, as well as in the maximum dominance rates and the dominant duration of sub-qualities among Baijiu. The young Baijiu were mainly characterized by the dominant sub-qualities of "burning" and "numbing", whereas for old Baijiu, "burning", "prickle", and "drying" were dominant. The application of TI and TDS provided dynamic and temporal profiles of pungency to fully characterize pungency differences of distilled beverages.

Temporal profile of low calorie lactose-free ice cream chocolate flavor: temporal dominance sensation and multiple time-intensity analysis

The food industry has a consumer market with growing interest in modified products, so this study aimed to evaluate consumer acceptance and characterize the temporal profile of traditional and lactose-free "low calorie chocolate ice creams". Six different samples were produced: three formulated with traditional whole milk sweetened with sucrose, sucralose and stevia and three formulated with lactose-free whole milk, also sweetened with the same sweeteners. Time-intensity analysis, temporal dominance of sensation and acceptance analysis were performed. The ice cream with lactose-free milk sweetened with stevia had a lower acceptance. The samples sweetened with sucrose were characterized by intensity, duration and dominance of the "sweet" and "chocolate flavor", while the samples sweetened with sucralose were characterized by intensity and duration of the "sweet" stimulus and also by the dominance of the "milk flavor" stimulus. The samples sweetened with stevia were characterized by greater intensity and duration of bitter stimulus, being also characterized by intensity of sweet taste and chocolate flavor. It can be verified that the use of stevia promotes relevant difference in lactose-free ice cream when compared to traditional ice cream, increasing the duration and dominance of bitter taste, as well impacting and decreasing the consumer acceptance. However, the addition of sucralose did not promote significant changes in the profile of both formulations.

Crispness, the Key for the Palatability of "Kakinotane": A Sensory Study with Onomatopoeic Words

Crispness is among the most important food textures that contribute significantly to palatability. This study investigated the association between the perceived crispness and palatability of five types of Japanese rice crackers known as “kakinotane.” Two experiments were conducted using the temporal dominance of sensations (TDS) and temporal drivers of liking (TDL) methods. As descriptors for the TDS evaluation, we used 10 Japanese onomatopoeias to indicate various attributes of crispness. We also measured the mastication sounds and electromyography (EMG) activity during mastication. Principal component analysis data revealed that principal component 1, representing moisture characteristics, contributed more than 60% in both experiments. The palatability of the stimulus, which was described as having a very soft, moist, and sticky texture, BETA-BETA, was significantly lower than the others. However, there was no significant relationship between the amplitude of mastication sound or EMG activity and palatability. We demonstrated that naïve university students can discriminate the fine nuances of the crispness of “kakinotane” using the TDS and TDL methods. Our findings also suggested that the onomatopoeias used as descriptors in the TDS method had a greater influence on describing the nuances of food texture than the physiological data.

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.

Multi-response approaches in product-focused investigations: Methodological variations across three case studies

Consumers' product experiences are increasingly uncovered using approaches that extend beyond acceptability and sensory perception. The present research is situated in this context and adopts a multi-response approach to jointly obtain attitudinal, conceptual, emotional, situational and/or sensorial evaluations. With the aim of greater methodological understanding, three case studies were conducted with samples in three product categories (fruit- and vegetable-based beverages (n = 10), seafood (n = 6) and chocolate (n = 7)) using consumers from New Zealand (n = 196), India (living in New Zealand) (n = 138) and China (n = 167), conducted in central location (CLT) or home-use test (HUT) settings. Showcasing this multi-response approach and demonstrating its versatility in product research is the main contribution of the research. Across the three case studies different combinations of response types and scaling formats were successfully used (including CATA (check-all-that-apply) questions, yes/no questions and rating scales), and it was also found that tasted foods and written stimuli (food names) served equally well as stimuli. The degree of liking or disliking for individual samples was a useful benchmark against which to interpret the other types of responses, and situational appropriateness, obtained as item-by-use (IBU) responses always contributed unique insights. Facial emoji to obtain product-emotion associations yielded less valuable insights than a conceptualisation task. As expected, and in accordance with the rationale for adopting a multi-response approach, the combination of response types yielded greater stimuli insights than would otherwise have been gained. This held for each of the three case studies and supported future applications using a multi-response approach that extends beyond many related initiatives by including four response types in each case study.

Dynamic aspects of salt reduction in tomato sauce by use of flavor enhancers and a bitter blocker

Several government agencies have established guidelines for the food industry to reduce sugar, fat, and salt in processed foods. The objective of this study was to determine the dynamic sensory profile of tomato sauce formulated with flavor enhancers, a bitter blocker and 50% sodium content reduction. The perception of consumers and a trained panel was explored. Consumers performed temporal dominance of sensations (TDS) and temporal acceptance (TA) while the trained panel performed time-intensity analysis (TI). TA indicated that flavor enhancers improve initial acceptance of a sample but that its masking effect weakens 30 s after ingestion. TI showed that despite promoting salty equivalence, substitute salts were not able to completely suppress the bitter taste characteristic of potassium chloride and the addition of lysine as a bitter blocker was the least effective strategy. In TDS the bitter taste was not dominant in any of the samples. However, the presence of unusual flavors/tastes to the consumers like metallic and umami seems to have interfered negatively in the evaluation of the flavors. Flavor enhancers have been widely used to reformulate processed foods in order to reduce sodium content, preserving sensory acceptance. This study provides information on the dynamic behavior of different salt substitutes.

Sensory characterization of cucumbers pickled with verjuice as novel acidifying agent

Verjuice is an acidic unfermented unripe grape juice that has recently been proposed as an alternative to vinegar in different food preparations. In this study, pickled cucumber preserves were industrially prepared using two dilutions of verjuice as acidifying agent and compared with the traditional vinegar-pickled samples. Samples were chemically characterized and subjected to sensory analyses using a trained panel and consumers. The different acidifying agents resulted in pickled cucumbers giving different olfactory and gustatory evaluations. No differences in appearance and texture were found. Despite showing chemical and sensory differences, pickles preserved with verjuice and vinegar had similar overall liking scores for visual, olfactory and gustatory aspects. A key feature of pickles prepared with verjuice is their lack of acetic acid potentially conferring them an additional value, suggesting that verjuice represents a viable alternative to vinegar for the production of pickles with distinctive sensorial properties.

Multi-Sip Time⁻Intensity Evaluation of Retronasal Aroma after Swallowing Oolong Tea Beverage

In most cases, a meal cannot be finished with a single bite and sip. During eating and drinking, consumers receive dynamic food perceptions from sensory attributes in foods. Thus, we performed multi-sip time–intensity (TI) evaluation of sensory attribute. In each of ten trials, the participant evaluated continuously the intensity of retronasal aroma for 60 s after swallowing oolong tea. We compared the TI parameters (I_max: maximum intensity, T_max: time point at which intensity reached the maximum value, AUC: area under the TI curve, D_plateau: duration between the first and last time points with values exceeding 90% of the maximum intensity, R_inc: rate of intensity increase between the first time points with values exceeding 5% and 90% of the maximum intensity, and R_dec: rate of intensity decrease between the last time points with values exceeding 5% and 90% of the maximum intensity) and TI curves among the ten trials, and approximated each TI curve with an exponential model. Some TI parameters (I_max, T_max, AUC, and R_inc) differed significantly between the first and subsequent trials. The TI curve was significantly lower in the first trial than in the subsequent trials, and TI curve during the time from starting the evaluation to reaching maximum intensity was significantly lower in the second trial than in the subsequent trials. The time constant of the fitted exponential function revealed that the decay of retronasal aroma intensity was slightly faster in the second through fourth trials than in the first and the fifth through tenth trials. These results indicate that olfaction might be more perceptive while consumers sip a cup of the beverage.

Dynamic profiling of different ready-to-drink fermented dairy products: A comparative study using Temporal Check-All-That-Apply (TCATA), Temporal Dominance of Sensations (TDS) and Progressive Profile (PP)

Despite the several differences in ingredients, processes and nutritional values, dairy foods as yogurts, fermented milks and milk beverages are widely accepted worldwide, and although they have their sensory profiling normally covered by descriptive analyses, the temporal perception involved during the consumption are rarely considered. In this sense, the present work aimed to assess the dynamic sensory profile of three categories of fermented dairy products using different temporal methodologies: Temporal Dominance of Sensations (TDS), Progressive Profiling (PP), Temporal CATA (TCATA), and compare the results obtained. The findings showed that the different sensory characteristics among the products are basically related to their commercial identity. Regarding the methods, all of them collected the variations between samples with great correlation between data. In addition, to detect differences in intensities, TCATA showed to be the most sensitive method in detecting textural changes. When using PP, a balanced experimental design considering the number of attributes, time intervals, and food matrix must be weighed. The findings are of interest to guide sensory and consumer practitioners involved in the dairy production to formulate/reformulate their products and help them choosing the most suitable dynamic method to temporally evaluate them.