From first to last bite: Temporal dynamics of sensory and hedonic perceptions using a multiple-intake 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.

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.

An Overview of Sensory Characterization Techniques: From Classical Descriptive Analysis to the Emergence of Novel Profiling Methods

Sensory science provides objective information about the consumer understanding of a product, the acceptance or rejection of stimuli, and the description of the emotions evoked. It is possible to answer how consumers perceive a product through discriminative and descriptive techniques. However, perception can change over time, and these fluctuations can be measured with time-intensity methods. Instrumental sensory devices and immersive techniques are gaining headway as sensory profiling techniques. The authors of this paper critically review sensory techniques from classical descriptive analysis to the emergence of novel profiling methods. Though research has been done in the creation of new sensory methods and comparison of those methods, little attention has been given to the timeline approach and its advantages and challenges. This study aimed to gather, explain, simplify, and discuss the evolution of sensory techniques.

Muscle activity during oral processing of sticky-cohesive foods

We investigated muscle activity during oral processing of sticky model foods. Chewing Time extracted from the EMG data distinguished the most sticky and least sticky model foods from the others, but was not a good discriminator between the other models. Mean chew work declined by 25.4%, while the median frequency shift (which is related to muscle fatigue) increased by 54.9% during oral processing for all the model foods, with the effect being greatest for the stickiest foods. We conclude that the degree of stickiness is not a trigger for swallowing and changes in the other bolus properties, such as softness, may influence muscle activity to a level at which we can swallow.

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.

Using Multiple Sensory Profiling Methods to Gain Insight into Temporal Perceptions of Pea Protein-Based Formulated Foods

The food industry is focused on creating plant-based foods that incorporate pea protein isolates. However, pea protein isolates are often described as having persistent beany, bitter, and astringent notes that can decrease the desirability of the resulting foods and make static sensory profiling difficult. To obtain more realistic descriptions of the sensory experiences associated with this category of products, researchers should consider using temporal methods and multi-intake methods, which allow consumers to evaluate whole food portions. This study aimed to understand better how product composition affected the sensory perception of pea protein-based beverages using three different sensory profiling methods. Particular focus was placed on beany, bitter, and astringent notes. Twelve pea protein-based beverages were formulated; they varied in pea protein type (pellet vs. isolate) and their content of gellan gum, salt, sunflower oil, sugar, and soy lecithin. They were evaluated by 16 trained panelists using three sensory profiling methods: static block profiling, mono-intake temporal dominance of sensations (TDS) profiling, and multi-intake TDS profiling. The static block and mono-intake TDS profiling methods yielded complementary results about the impact of beverage composition on attribute perceptions. Static block profiling revealed that beaniness was mainly affected by gellan gum and oil content and that bitterness and astringency were mainly affected by protein type and gellan gum content. Mono-intake TDS profiling highlighted the dynamics of beaniness and the strong persistence of astringency, and its results suggested that higher gellan gum and salt contents could limit this persistence. Multi-intake TDS profiling found that, throughout the consumption of a full product portion, beaniness and bitterness decreased, indicating an adaptation effect, while fattiness increased, indicating a build-up effect. This study has increased the understanding of how pea protein-based beverages are perceived under conditions that more closely resemble those associated with real-life consumption. It has also revealed how product formulation can reduce bitterness and astringency.

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.

Sensory Nudges: The Influences of Environmental Contexts on Consumers' Sensory Perception, Emotional Responses, and Behaviors toward Foods and Beverages

Food products with highly acceptable flavors are not always successful in the marketplace. Sales of identical food products sold in two different stores often differ. Patrons’ choices of specific menu items vary depending on menu designs at restaurants. Such examples suggest that consumer behavior related to eating, preparing, or purchasing foods and beverages is typically complex, dynamic, and sensitive. There is a growing body of evidence that environmental cues surrounding foods and beverages can modulate consumer perception and behavior in the context of eating and drinking. In light of increasing interest in environmental cues, this Special Issue was designed to introduce recent research that highlights how sensory cues derived from environmental cues can modulate consumer perceptions, emotional responses, and behavior related to foods and beverages. The eleven articles addressed in this Special Issue provide informative and insightful findings that may be applied to a wide range of food-related sites, including grocery stores, retail markets, restaurants, dining facilities, and public dining areas. The findings from these articles also suggest that product developers, sensory professionals, retailers, marketers, and business owners should consider not only sensory aspects of food products, but also sensory cues derived from surrounding contexts to better understand consumer perception, acceptability, and behavior toward their food products.