Dynamic aspects of liking: post-prandial persistence of sensory specific satiety

The time dependence of the liking of foodstuffs was investigated in a study with 25 subjects, consisting of three parts: (1) on day one, a sensory specific satiety study, which was extended until 125 min after consumption; (2) on days two to seven, a repeated in home taste and evaluation study; (3) on day eight, a second sensory specific satiety study as in 1.In parts 1 and 3, subjects were asked to eat either cheese biscuits or pears in light syrup to satiety. The change in liking of both foodstuffs, after eating one of the two foodstuffs to satiety, was followed during 125 min. In part 2, the same subjects were asked to taste and evaluate each product at home, every day for six days.In the sensory specific satiety studies (parts 1 and 3) a significant decrease in liking was observed for the product eaten to satiety, as long as 125 min after consuming that product to satiety. For both products contrast effects were observed: the liking of the uneaten product increased after eating the other product to satiety, while the liking of the eaten product decreased. This contrast effect lasted longer after eating cheese biscuits to satiety, than after eating pears to satiety.In the in home taste and evaluation study, a significant and linear decrease in liking was observed for both products during six days. There was a significant effect (p < 0.05) of eating cheese biscuits to satiety in the sensory specific satiety study on day 1, on the liking ratings of the in home consumption study. No such effect was observed for the pears.The results indicate that sensory specific satiety is relatively strong for more than 2 h after consumption and can have effects on liking ratings for more than 24 h. These effects were different for the products tested. Based on these results, we suggest that combining eating a product to satiety and in home evaluation over several days, could possibly be useful as an accelerated method to predict changes in liking upon repeated consumption.     

Satiety and consumers' perceptions: What opinions do Argentinian and Brazilian people have about yogurt fortified with dairy and legume proteins?

This study (1) evaluated the perceptions of Argentinian and Brazilian consumers regarding yogurt fortified with dairy proteins, legume proteins, or a combination of both, and (2) determined the satiety expectations of these foods as well as the consumers' intentions to taste and purchase protein-fortified yogurt. A total of 298 Argentinian and 100 Brazilian participants completed an online survey for this study. The free word association technique was used to investigate their perceptions about “satiety” as a verbal stimulus and 6 concepts of yogurt as visual/verbal stimuli (yogurt, set yogurt, skim set yogurt, skim set yogurt with a high content of dairy proteins, skim set yogurt with a high content of legume proteins, and skim set yogurt with a mix of dairy and legume proteins). The expected satiation and intentions to taste or purchase were evaluated using categorical scales. Regardless of their cultural background, participants from both countries expressed similar associations with the stimuli presented. Yogurt and set yogurt were associated with consumption occasions, sensory characteristics, liking, and foods, whereas skim yogurt was associated with diet food. Products fortified with proteins were associated with healthy foods, regardless of the protein source, and they yielded the highest rates for expected satiation. Brazilian participants were more likely to taste the food with a combination of proteins; however, participants from both countries were indifferent to purchasing the product. Important characteristics in the design and marketing of these products were pleasant sensations, such as “fullness,” “satisfied,” and snacks to eat “on the go,” and the vegetarian consumers' segment. The combination with fruits or cereals, creaminess, and vanilla flavor should also be considered. The study findings could have implications for the dairy industry when designing yogurt fortified with proteins and communicating the nutritional and wholesome properties of these products.     

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.     

Exploring relationships between satiation,perceived satiety and plant-based snack food features

We aimed to identify relations between satiation and subsequent satiety for six plant-based foods (apple, avocado, banana, carrot, chick pea and macadamia) using a panel of ten healthy participants and a complete crossover randomised design. Food was served as a mid-morning snack ad libitum over 20 min until participants were comfortably full, and subsequent satiety was monitored for up to 180 min. Carrot and macadamia had significantly higher perceived fullness during eating, but also significantly lower perceived satiety per gram than other foods. Food energy factors had no strong relationship with perceived fullness, but were significantly positively correlated with satiety. Mastication number had significant effects on both perceived fullness (negative) and satiety (positive). This pilot study showed that plant food factors affecting perceived fullness during eating and subsequent satiety are different, and suggests how portion control through satiation for different plant-based snacks may influence both energy intake and subsequent satiety.     

Food satisfaction: Integrating feelings before,during and after food intake

Consumers’ satisfaction is important for the food industry to ensure product success. Determinants to food satisfaction are multifactorial and a method approaching the multiple determinants would provide a detailed picture of determinant behind consumers’ hedonic food appreciation.The aims of this study were (1) to develop a method that could give detailed information about sensory- and food satisfaction (2) to study differences in sensory satisfaction in a case study, and (3) to study the factors related to food satisfaction. Focus group interviews and a literature study provided an overview of factors with potential to affect food satisfaction. A total of four questionnaires, covering factors before-, during- and after intake as well as demographics, were developed to measure factors related to satisfaction. The questionnaires were utilised in a cross-over consumer study with 79 subjects consuming two sensory different variants of chicken soup. Soups were sensory evaluated utilising expert statements. The consumer study showed that sensory satisfaction was highly influenced by liking of taste and appearance, whereas liking of odour and texture influenced sensory satisfaction moderately. Food satisfaction was influenced by factors measured during- and post intake; sensory satisfaction, fulfilment of expectations, reason for ending intake, product performance relative to expectations, hunger and fullness after intake were found highly influential in food satisfaction. Pre-intake factors did not substantially influence food satisfaction. Though the use of multiple variables gave a detailed picture of factors involved in food satisfaction, there was still variation in food satisfaction that remained unaccounted.     

Provision of visually appetising and high-energy maize soup as an in-between meal for older consumers

The objective of this study was to investigate the effects of enriched energy density and visual topping on maize soup’s intake, overall liking, taste liking, food-evoked emotion and perceived familiarity among older home-dwelling people. This study consisted of two tests: in the first test, the most appetising soup was chosen from six high-energy soups topped with different condiments by testing participants’ rankings based only on appearance; while in the second test, participants tasted the most visually appealing maize soup (high-energy maize soup topped with parsley), as well as topping-free high-energy maize soup and low-energy maize soup. Enriched energy density significantly increased the energy intake of maize soup, and visual topping significantly increased both the weighed intake and energy intake of high-energy maize soup. A combined sensory dimension modification of maize soup by enriching energy density and adding visual topping positively affected weighed intake, energy intake, overall liking and food-evoked emotion of maize soup. Slight changes of meal appearance by adding visually appetising toppings could be an effective method to encourage older consumers’ food consumption. In addition, combined sensory enhancement for food could have synergetic effect on older people’s food consumption and eating experience.     

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.     

Contribution to the understanding of consumers’ creaminess concept: A sensory and a verbal approach

Creaminess is an integrated term, which is reported to depend on textural properties, fattiness, flavour and pleasantness of food products. We aimed to determine whether consumers weight these attributes similarly or not when assessing creamy products. To determine this, sensory properties of 12 dairy products were characterized by a trained panel. Then, new consumers rated the creaminess and their liking for these products, and wrote down their own definition of creaminess. A cluster analysis done on the consumers’ creaminess scores revealed three clusters, which were characterized through correlation with trained panel data, liking data and definition data. For all clusters, consumers used words related to texture and pleasantness when defining creaminess. Nevertheless, from verbal and sensory data, product properties underlying creaminess construct vary among clusters. While a first cluster put emphasis on texture, a second one put emphasis on fattiness and natural flavour, and a last put emphasis on sweetness.     

The influence of oral lubrication on food intake: A proof-of-concept study

As overeating, overweight and obesity remain public health concerns, it is crucial to design satiety-enhancing foods that suppress appetite and lower snack intake. Existing research identifies oro-sensory targets to promote satiation and satiety, yet it remains unclear as to whether it is ‘chewing’ or ‘oral lubrication’ that might amplify satiation signals. In this study, techniques from experimental psychology, food material science and mechanical engineering have been combined to develop model foods to investigate the role of chewing and oral lubrication on food intake. Novel model gels, similar in pleasantness, were given as a preload then their effects on subjective appetite and intake of a salty snack were measured in a between-subjects design. Three mint flavoured hydrogels were engineered to vary in their texture (fracture stress) and lubrication (inverse of coefficient of friction), and a control group received mint tea. Results showed that snack intake was suppressed by 32% after eating the low chewing/high lubricating preload compared to the high chewing/low lubricating preload (p < 0.05). Hunger ratings decreased from t₁ to t₃ (p < 0.05), however differences between conditions were subtle and not significant. Thus, this proof-of-concept study demonstrates that manipulating oral lubrication is a promising new construct to reduce snack intake that merits future research in the oro-sensory satiety domain.     

An itinerant sensory approach to investigate consumers' perception and acceptability at a food exhibition

In a food exhibition where several producers of the same product category are present at the same time, consumers usually have the opportunity to taste several free samples of the same product type, thus they can experience and compare the sensory characteristics of each and evaluate their liking for each sample tasted. This study assessed the potential of an itinerant sensory data collection in understanding the consumers' perception and acceptance of cheese during a multiple tasting experience at a food exhibition. Subjects tasted seven samples of Parmigiano Reggiano cheese aged for different times (24 and 36 months) at seven producer stands and recorded their evaluations using tablets, on which an application specifically developed for this study was installed. This evaluation situation was defined as “pseudo-natural,” in opposition to the “natural” and the “naturalistic” settings. The itinerant sensory session comprised a liking test, a rate-all-that-apply (RATA) test using a just about right (JAR) scale, a food pairing test, and a questionnaire. Consumers significantly (p < 0.05) discriminated the cheeses as a function of the aging time, describing with different attributes the 24 months (sweetness, fresh fruit, grass, yogurt, butter flavors, elasticity, and humidity) and the 36 months (saltiness, bitterness, sourness, spicy, aromatic herbs, cheese rind flavors, crumbliness, granularity, hardness, and hotness) aged products. The combined application of regression models, Penalty-Lift analysis, and decision tree models in investigating the relationships between liking and the RATA data, provided results revealing that the attributes elasticity, sweetness, humidity, fresh fruit, and butter were the main drivers of liking. Whereas, the attributes sourness, bitterness, and hardness were the main drivers of dislike. Therefore, even though no significant differences in terms of liking were observed among the tested cheeses, consumers preferred the attributes more frequently perceived in the least aged products. In conclusion, the presented itinerant sensory approach had provided meaningful information to understand the consumers' cheese perception and acceptability. In the future, it could advantageously be applied for studying food perception in other situations in which subjects naturally choose or consume several products while freely moving from one to another (e.g. self-service restaurant).     

The silver sensory experience – A review of senior consumers’ food perception,liking and intake

It is commonly assumed that sensory impairments occurring with age negatively affect older people’s intake of foods in terms of both quality and quantity. This review discusses evidence published on the effects of age on sensory perception and the consequences for independently living seniors’ perception, liking and intake of food products. Because of anatomical changes in all the senses involved in human food perception, on average seniors perceive a lower flavour intensity than younger adults, are less sensitive to changes in the flavour profile of foods, and show a decreased ability to discriminate between different intensity levels of flavour and/or taste attributes. However, despite these differences in their sensory perception of foods, young adults and seniors seem to differ less in their initial hedonic appraisal of food products. Nonetheless, more research is needed to determine whether multisensory enrichment of foods across different modalities may lead to increased food liking in seniors both with and without olfactory impairment. Although limited, the current evidence suggests that sensory performance may be positively associated with BMI or body weight in specific senior populations. In addition, seniors fail to show a decreased appreciation of an eaten food, thereby increasing the risk of a monotonous diet. Taken together, these findings highlight the need for appropriate interventions and/or foods to improve and maintain adequate quantity and quality of food intake among independently living seniors, and especially those with low sensory performance. Such interventions should be holistic rather than focused on one modality and may also incorporate hedonic modulators such as past experiences, affective factors and external cues, e.g. brand names, labels or food packaging. In interventions and product development, segmentation of the senior consumer market is strongly advised to identify more homogeneous subgroups in order to deal with the large heterogeneity between independently living seniors. It is concluded that one size of the silver food experience will most likely not fit all senior consumers!     

The effect of the research setting on the emotional and sensory profiling under blind,expected, and informed conditions: A study on premium and private label yogurt products

Although sensory and emotional evaluation of food products mostly occurs in a controlled laboratory environment, it is often criticized as it may not reflect a realistic situation for consumers. Moreover, products are mainly blind evaluated by participants, whereas external factors such as brand are often considered as key drivers of food choice. This study aims to examine the role of research setting (central location test versus home-use test) and brand information on the overall acceptance, and sensory and emotional profiling of 5 strawberry-flavored yogurts. Thereby, private label and premium brands are compared under 3 conditions: blind, expected, and informed (brand information). A total of 99 adult subjects participated in 3 sessions over 3 consecutive weeks. Results showed that overall liking for 2 yogurt samples was higher in the laboratory environment under the informed evaluation condition, whereas no effect of research setting was found under the blind and expected conditions. Although emotional profiles of the products differed depending on the research setting, this was less the case for the sensory profiles. Furthermore, brand information clearly affected the sensory perception of certain attributes but had less influence on overall liking and emotional profiling. These results indicate that both scientists and food companies should consider the effect of the chosen methodology on ecological validity when conducting sensory research with consumers because the laboratory context could lead to a more positive evaluation compared with a home-use test.     

Portion size selection as related to product and consumer characteristics studied by PLS path modelling

Expectations of satiation and satiety have been increasingly investigated because of the interest in how they, along with liking, can modulate portion-size selection. Consumer characteristics can also be important when consumers select their portion size. However, the contribution and interaction of consumers and product aspects to portion size selection has not been unveiled. This study aims to better understanding these complex relations by simultaneously assessing the relative influence of consumer characteristics and product related properties on portion size selection utilizing PLS-Path Modelling (PLS-PM) approach.In this study, consumers (n = 101) answered questions regarding attitudes to health and hedonic characteristics of foods, and completed hunger and fullness questions. In an evaluation step, they tasted eight samples of yogurt with different textures and rated liking, expected satiation, expected satiety and portion size. The consumers were also classified on their mouth behaviour by using the JBMB™ tool.Results showed that liking, satiation, satiety and portion size depended firstly on the thickness, and then on the particle size of samples. PLS-PM was used to generate a model, indicating that liking was a direct predictor of portion size, with a stronger effect than satiation or satiety. The relationship between liking and satiety was observed both in direct direction (liking-satiety) and also indirect direction throughout satiation (liking-satiation-satiety). The former was negative effect and the latter was positive effect depending on the criteria which consumers used.These findings implied that liking is a main factor in the prediction of portion size however the relations are complex.     

Analysing relations between specific and total liking scores

The objective of this article is to present a new statistical approach for the study of consumer liking. Total liking data are extended by incorporating liking for specific sensory properties. The approach combines different analyses for the purpose of investigating the most important aspects of liking and indicating which products are similarly or differently perceived by which consumers. A method based on the differences between total liking and the specific liking variables is proposed for studying both relative differences among products and individual consumer differences. Segmentation is also tested out in order to distinguish consumers with the strongest differences in their liking values. The approach is illustrated by a case study, based on cheese data. In the consumer test consumers were asked to evaluate their total liking, the liking for texture and the liking for odour/taste.     

Application of whey protein emulsion gel microparticles as fat replacers in low-fat yogurt: Applicability of vegetable oil as the oil phase

Low-fat, healthy yogurt is becoming increasingly favored by consumers. In the present study, whey protein emulsion gel microparticles were used to improve the quality of low-fat yogurt, and the effects of vegetable oil emulsion gel as a fat substitute on the qualities of low-fat yogurt were investigated, expecting to obtain healthier and even more excellent quality low-fat yogurt by applying a new method. First, emulsion gel microparticles were prepared, and then particle size distribution of emulsion gel and water holding capacity (WHC), textural properties, rheological properties, microstructure, storage stability, and sensory evaluation of yogurt were carried out. The results showed that yogurt with emulsion gel had significantly superior qualities than yogurt made with skim milk powder, with better WHC, textural properties, rheological properties, and storage stability. The average particle size of whey protein-vegetable oil emulsion gel microparticles was significantly larger than that of whey protein-milk fat emulsion gel microparticles, and the larger particle size affected the structural stability of yogurt. The WHC of yogurt made with whey protein-vegetable oil emulsion gel microparticles (V-EY) was lower (40.41%) than that of yogurt made with whey protein-milk fat emulsion gel microparticles (M-EY; 42.81%), and the texture results also showed that the hardness, consistency, and viscosity index of V-EY were inferior to these of M-EY, whereas no significant differences were found in the cohesiveness. Interestingly, the microstructure of V-EY was relatively flatter, with more and finer network branching. The whey separation between V-EY and M-EY also did not show significant differences during the 14 d of storage. Compared with yogurt made with whey protein, vegetable oil, and skim milk powder, the structure of V-EY remained relatively stable and had no cracks after 14 d of storage. The sensory evaluation results found that the total score of V-EY (62) was only lower than M-EY (65) and significantly higher than that of yogurt made with skim milk powder. The emulsion gel addition improved the sensory qualities of yogurt. Whey protein emulsion gel microparticles prepared from vegetable oil can be applied to low-fat yogurt to replace fat and improve texture and sensory defects associated with fat reduction.     

Preference mapping of salmon–sauce combinations: The influence of temporal properties

Food–food combinations are complex stimuli where the dynamic nature of sensory interactions plays an important role for perception and acceptance. The aim of this study was to investigate if TDS provides additional insight about drivers of liking compared to DA in a preference mapping context. A trained sensory panel performed DA and TDS on six different samples (combinations of salmon and culinary sauces), and sixty-one consumers rated acceptance for the same samples. In addition to TDS SCORES, this study introduces the use of extracted parameters based on dominance information from TDS; the area of dominance based on the integrated area under the dominance curves and the number of dominant sensations and blends within a specified time period. Results from preference mappings showed that the TDS approaches generally provided similar but less detailed information regarding drivers of liking and disliking compared to DA. Moreover, with the use of the extracted TDS parameters, it was possible to identify the time of dominance of certain attributes and the number of perceived sensations and blends in specific time periods as potential drivers of liking and disliking. The results also showed that TDS has a potential to provide complementary information about the dynamic nature of sensory interactions in food–food combinations compared to DA.