Alternating temporal dominance of sensations and liking scales during the intake of a full portion of an oral nutritional supplement

Measurement of liking with consumers is often performed on a single sip or mouthful of the product and results in a single liking score that does not necessarily reflect the liking over consumption of a whole product. A dynamic approach could provide this type of information. Thus, obtaining reasons why the liking score is changing over consumption could help to gain insights for product improvement. Recently, Thomas, Visalli, Cordelle, and Schlich (2015) suggested collecting with the same consumers liking scores dynamically and Temporal Dominance of Sensations (TDS) during mono-intakes of flavored cheeses, in two independent sessions. This new type of sensory data has been analysed at individual level to identify “temporal drivers of liking” for each product.The present paper further develops this method consisting of collecting TDS and dynamic liking data in the same session and during the consumption of the full portion of a product. The products used to experiment this new method were two commercial oral nutritional supplements (ONS) assessed by 65 consumers over two lab sessions separated by one week.The protocol consisted of a TDS evaluation of 5 flavor, 2 texture and 3 taste sensations during each sip, immediately followed by a liking scale. This protocol was repeated over sips. This method, named “Alternated Temporal Drivers of Liking” (A-TDL), required that consumers record liking changes and do TDS over sips during food consumption. Results showed that one of the two ONS was more liked than the other and consumed in a larger volume resulting in a higher energy intake. In contrast, the other product resulted in a stronger thirst and presented more negative temporal drivers of liking (dry, metallic, filming) over the consecutive sips.     

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

Mapping food-evoked emotions in addition to sensory profiling is topical. In sensory profiling, the Temporal Dominance of Sensation (TDS) method focuses on the assessment of the temporal evolution of dominant sensory attributes over time. We hypothesize that food-evoked emotions also show temporal dynamics that can be related to dynamic sensory perception. This study assessed temporal dynamics of sensory and emotional attributes during chocolate tasting. We used TDS to determine dynamic sensory properties of dark chocolates providing a list of 10 sensory attributes. Comparably, Temporal Dominance of Emotions (TDE) was assessed by replacing the sensory attributes with 10 emotional attributes. Sixty-two participants assessed TDS and TDE of five commercially available dark chocolates (plain and flavoured). Multivariate comparisons (Hotelling test) showed significant differences between products based on the dominance duration of sensory (p < 0.05) and emotional attributes (p < 0.05). TDS difference curves revealed products to differ based on their dominant sensory attributes, with different attributes peaking at different time moments. TDE difference curves showed that products also differed in the temporal distribution of dominant emotional attributes. Comparing the average dominance rates between plain dark and flavoured dark chocolates revealed that for flavoured dark chocolates mainly flavour attributes and positive/active emotions were perceived as salient whereas for plain dark chocolates textural as well as taste attributes were dominant accompanied by more negative/non-energetic emotions. A joint CVA plot on the duration of dominance for sensory and emotional attributes per product revealed that temporal evolution of sensory – and emotional attributes was related. This suggests a mutual reciprocity between those two entities (sensory and emotional attributes) resulting in more complex, richer product characterization. In conclusion, these findings show TDE to be a promising new venue in characterising food-evoked emotions in relation to sensory profiling.     

Temporal methods: Are we comparing apples and oranges?

A workshop held at the 2018 Sensometrics conference in Montevideo aimed at a data-based comparison between three temporal methods, namely Temporal Check-All-That-Apply (TCATA), Temporal Dominance of Sensations (TDS), and Temporal Dominance of Sensations by Modality (MTDS). Data on 8 yoghurts designed following a full-factorial design have been evaluated using the three protocols. In this paper, we compare the data obtained with regard to discriminative power and highlight potential pitfalls when making significance-based comparisons. TCATA is found to provide overall highest discrimination, while for special purposes, the other methods may have advantages. We further compare the dominance and selection rates from the methods, addressing the arbitrariness of necessary standardizations. Finally, we compare results from correspondence analyses with trajectories, showing noteworthy differences between the protocols. In the discussion, it is argued that a reasonable comparison between the methods might not be possible or even reasonable, as they address quite different concepts. Rather than being considered as alternatives for the same objective, they should better be considered as complimentary, addressing different project needs.     

Temporal Dominance of Sensations paired with dynamic wanting in an ad libitum setting: A new method of sensory evaluation with consumers for a better understanding of beer drinkability

While drinkability is of paramount importance when discussing beer, there is no established methodology to assess it. The main objective of the present study was to develop a new method of sensory evaluation with consumers to obtain a better understanding of beer drinkability. With the aim of being practically and effectively used in a wide range of consumer tests in an ad libitum consumption setting, a new method called the “Multiple-sip Drinkability Test” was developed to evaluate beer drinkability defined as “the will of drinking”. The method is based on Temporal Dominance of Sensations (TDS) paired with dynamic wanting.This paper presents the test designs and the results from two studies of four commercial Japanese beers, one conducted with an expert sensory panel and the other with a naïve panel of consumers. The results revealed the importance of monitoring dynamic wanting over sips. In both studies, product differences in wanting, almost nonexistent at the beginning, gradually became larger.These studies also elicited the characteristics of beer with high drinkability. The product that attained the highest wanting scores in both studies was perceived as having less of a standout flavor, thereby producing fewer build-up effects on sensory perceptions, which suggests that the greater the sensory load produced by a beer, the less one wants to drink it continuously. This methodology should be used with different types of beers and consumers to obtain a broader understanding of the sensory drivers of beer drinkability and consumer satisfaction.     

Dutch consumers do not hesitate: Capturing implicit ‘no dominance’ durations using Hold-down Temporal Dominance methodologies for Sensations (TDS) and Emotions (TDE)

In the ‘classic’ Temporal Dominance (TD) method, panellists are instructed to select a dominant attribute, which remains dominant until another attribute is selected. This procedure does not allow recording ‘no dominance (ND)’. ND periods can occur because of indecisive selection behaviour due to hesitation or uncertainty about attribute selection and time needed to switch from one attribute to another. ND periods may create noise in TD data. ND can be recorded implicitly using a ‘Hold-down’ procedure, where panellists actively hold down the attribute button that is perceived dominant, but release it when no longer dominant. The ‘Hold-down’ procedure allows subjects to report indecisive behaviour simply by not holding down a button. This study compared the ‘classic’ and ‘Hold-down’ TD methodologies. One hundred and thirty-seven participants evaluated four dark chocolates in two sessions, one for sensory (TDS) and one for emotion (TDE) evaluations. Participants employed either classic (n = 68) or Hold-down (n = 69) TD following a between subjects design. Similar dominance rates and dynamic evolutions of attributes during consumption were observed for both methods. ND durations between attribute selections were shorter than 1 s during sensory and emotion evaluations. Such short ND durations unlikely reflect periods of true hesitation, but rather reflect the time needed to switch between dominant attributes. No evidence is found for Hold-down TD outperforming classic TD in terms of sensitivity and discrimination ability. In conclusion, irrespective of the conceptual likelihood regarding the occurrence of ‘no dominance’ periods, the present study failed to demonstrate moments of hesitation using the ‘Hold-down’ procedure.     

Panel and panelist agreement for product comparisons in studies of Temporal Dominance of Sensations

Temporal Dominance of Sensations (TDS) is a sensory method to investigate the most dominant attribute in consumer perception over time. In this paper, we aim at investigating (dis-)agreement as a performance measure of the overall panel as well as of individual panelists. This helps to check the data quality and, if necessary, to direct the panel leader in subsequent training.Panel and panelist agreement with regard to product differences is a main aspect of panel performance. The interaction between panelist and product serves as a useful measure of this agreement. This interaction can only be determined if panelists evaluate at least some of the products repeatedly. A simple test statistic is used here to investigate possible panelist disagreement by means of randomization tests.We propose a test for overall panel agreement on product differences as well as tests for each panelist. All tests can be performed as well by sensory attribute, by point in time, and by attribute at each point in time. In addition, we propose a way to graphically display the many thousands of p values derived. The method is applied to data from a TDS study on six wheat flakes, indicating that there is substantial disagreement between the panelists. For all panelists, we identify the attributes on which they disagree with the remainder of the panel. If these disagreements are confirmed in other studies, the panelist might require additional training.     

Contribution of temporal dominance of sensations performed by modality (M-TDS) to the sensory perception of texture and flavor in semi-solid products: A case study on fat-free strawberry yogurts

This study aimed to perform Temporal Dominance of Sensations by modality (M-TDS) combined with a multi-intake approach to investigate texture and flavor perception in semi-solid products. Trained panelists (n = 15) evaluated fat-free strawberry yogurts enriched with functional proteins involving texture modifications. As yogurt is a semi-solid product, its in-mouth residence time is short. A multi-intake approach was therefore expected to give more reliable information about the sensory properties perceived by panelists. The two modalities of texture and flavor were analyzed separately to characterize the effect of added proteins. Trials were made according to an experimental design with two factors (protein type and concentration) and three levels each. Different statistical treatments, taking or not the temporality of attributes into account, were performed on standardized and non-standardized data. The implementation of M-TDS was essential to highlight differences of flavor perception in addition to the more evident texture modifications. The study of sensory trajectories evidenced that texture modifications, induced by the use of different whey proteins, slightly modified the perception of flavor and sweetness. The global flavor perception of the samples varied with the number of spoons, which particularly impacted the taste attributes. This study highlighted the importance of using M-TDS when studying texture and flavor in semi-solid products, and the relevance of the multi-intake approach to characterize flavor perception. This methodology enabled panelists to evidence both marked texture differences and subtler flavor modifications, and these useful data were emphasized by combining different statistical treatments.     

感觉的时间优势评价方法及其应用

感觉的时间优势评价方法(TDS)是一个相对较新的概念,用来评价产品在一定时间内如咀嚼过程中的优势感官性质及其变化。这种方法通常被用来描述产品随时间变化的特点,它只需要研究在评价的各个阶段占优势的感官属性。TDS方法旨在研究香气成分和呈味物质释放与感知之间的联系,从而更好地理解它们。从食品生产和发展的角度讲,动态和多感官方面的对食品感官进行认知将会产生良好的效果,可以让消费者更好地了解品尝过程来评估食品的可接受性和感官性状。本文主要从如何获得TDS数据、TDS曲线的建立以及优化,TDS数据分析和TDS的应用来介绍TDS方法。      

Dynamic texture perception in plant-based yogurt alternatives: Identifying temporal drivers of liking by TDS

As texture properties in novel food categories have a crucial role in consumer acceptance, mouthfeel profile of different plant-based yogurt-like semi-solid products were studied and compared to dairy yogurts. Mouthfeel properties of five plant-based yogurt-like products and two dairy yogurts were analyzed using temporal dominance of sensations (TDS) with consumers (n = 87). The attributes evaluated were thick, thin, creamy, watery, sticky, and foamy. Following TDS, overall liking and mouthfeel liking were evaluated using a 7-point hedonic scale. Temporal drivers of mouthfeel liking were studied using correspondence analysis and penalty-lift analysis with different time points during mastication. For penalty-lift analysis TDS data was analyzed as check-all-that-apply (CATA) data. Results from the present work show that mouthfeel perception in non-dairy yogurt alternatives is a dynamic process. Attributes typically used to describe dairy yogurts are also relevant for describing non-dairy yogurt alternatives. Yogurt alternatives and dairy yogurts can be similar and equally liked by their mouthfeel profile. Temporal drivers of liking in plant-based products are thickness and creaminess and temporal drivers of disliking are thinness and wateriness. In this study, the first dominant attributes were found to have a stronger impact on mouthfeel liking than the dominant attributes perceived later during mastication.     

Sweetener solutions as binding agents for amaranth bars: evolution of temporal dominance of sensory attributes

The objective of the study was to determine the effects of replacing binding agents with commercial low-calorie sweetener solutions on the physicochemical and temporal dominance of sensations in amaranth bars. Five baked amaranth bar formulations (Sweetener-Solution-Formulated Amaranth Bars: SSFABs) were prepared using solutions of erythritol, sucralose, steviol and two sucrose concentrations (50% and 25%). A commercial bar (COMM) was used as a control. Proximal, pH, water activity, texture and colour were measured. Temporal dominance of sensations (TDS) was used to determine dominant attributes in time. In general, SSFABs showed a higher moisture, ash and protein content compared to COMM. Carbohydrates and total crude fat were lower in SSFABs than in COMM. Dominant attributes were Crispy, Dry, Sweet and Amaranth. Erythritol formulation was similar to the commercial bar in terms of maximum dominance rate. Replacement of binding agents impacted on the evolution of dominant attributes in amaranth bars.     

Visualization of temporal differences between dominant perceptions in temporal dominance of sensations (TDS) and temporal check-all-that-apply (TCATA) perceptions using dominance-highlighted TCATA (dTCATA) curves

The temporal dominance of sensations (TDS) method measures dynamic changes of panelists’ attention to the sensory attributes of products. The temporal check-all-that-apply (TCATA) method measures all sensory attributes perceived at each moment of an evaluation. However, unlike in TDS, significant levels cannot be calculated in TCATA. This study proposes the use of dominance-highlighted TCATA (dTCATA) curves, which are highlighted TCATA curves that show significant time periods for the TDS data of different panels. Twelve R&D panelists evaluated five commercial corn soups using the TCATA method. Then, 125 consumer panelists evaluated the same products using the TDS method. The dTCATA curves showed TCATA curves for all attributes for each product evaluated by the R&D panel highlighted with the dominance rates identified by the consumer panel in the TDS evaluation. For example, for product 1, some attributes (sweet, viscosity) showed relatively high citation proportions in the TCATA evaluations of the R&D panel and significant dominance rates in the TDS evaluations of the consumer panel. In contrast, consommé flavor showed relatively low citation proportions in TCATA but significant dominance rates in TDS. By merging TDS and TCATA data, we could compare consumers’ dominant sensations with the evaluations of R&D panelists. This comparison could provide useful insights to product developers. In some cases, we observed attributes with significant dominance rates that were under-identified by the R&D panel in TCATA. This could suggest that most of the R&D panel may not have perceived these attributes; therefore, during product development, these attributes should be carefully considered.     

琥珀酸二钠与谷氨酸钠相互作用及喜好度分析

采用成对比较检验,测定0.300?g/100?mL谷氨酸钠和不同质量浓度琥珀酸二钠（0.010、0.020、0.030、0.050?g/100?mL及0.100?g/100?mL）复合溶液的相对谷氨酸钠质量浓度,并采用9?点标度法对其喜好性进行分析。研究表明,随着琥珀酸二钠添加量的提高,复合溶液的整体鲜味强度先大幅增加而后降低,在谷氨酸钠与琥珀酸二钠添加比例为6∶1时达到峰值;同时随着琥珀酸二钠添加量的增加,复合溶液的喜好度先略有上升后急剧下降,在谷氨酸钠与琥珀酸二钠添加比例为15∶1时达到峰值。综合以上指标,谷氨酸钠与琥珀酸二钠在实际应用中的添加比例不宜超过10∶1。本实验结果表明琥珀酸二钠与谷氨酸钠的相互作用关系,为琥珀酸二钠的实际应用提供理论参考。