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There is limited knowledge of the characteristics, differences, and similarities of the bacterial composition in residential kitchens. Here, we report the microbiota of cleaning utensils (sponges and cloths) and five different surface samples in 74 households across five European countries.

A more plant-based diet will contribute to food sustainability. Achieving this change requires collaboration across disciplines which is not easy to achieve. This article illustrates how interdisciplinary collaboration in a large research project can be facilitated through a design-led innovation process juxtaposing approaches from design and science. Consumer insights were used in creative workshops to ideate and develop packaging and product concepts for plant-based food focusing on ‘environment’, ‘health’ and ‘Norwegian’ design imperatives. Learning loops of alignment – creation – feedback were applied to design and test six packaging prototypes of two product categories (Pea Porridge, Faba Bean Drink). Qualitative feedback was collected from 147 consumers and a quantitative survey with 1102 Norwegian consumers tested product expected liking and product-concept match. Younger consumers and users of plant-based products exhibited a higher expected liking vs. non-users and older respondents. Packaging design adopted for specific consumer segments can positively contribute to a shift to more plant-based diets. We show how a dynamic interdisciplinary innovation approach can be powerful to creating new product ideas, getting consumers’ input and fostering collaboration and learning among disciplines. We offer other researchers and the food industry actionable opportunity areas and design imperatives for their innovation activities around plant-based food.

Emoji have been suggested as an alternative for word-based questionnaires to measure consumers' emotional associations of food products. As the uptake of emoji in sensory and consumer science is accelerating, consumer research regarding the meaning of emoji in the specific context of eating is still lacking. The overall aim of this study was to gain insights on the valence, arousal and general similarities-dissimilarities in meaning of 52 facial and non-facial emoji in a food context. Adult consumers (n = 460) participated in an online survey including a personalized evoked context priming task for their latest eating occasion, a Projective Mapping (PM) task and a manikin-based valence/arousal evaluation task. As 52 emoji may be overwhelming to assess for the subjects, the second aim of the study was to test out an incomplete block design approach showcasing only 15 emoji per consumer, wherein 7 were recurrent across participants and 8 varied. All participants also assessed an additional 'latest eating occasion' emoji. INdividual Differences SCALing (INDSCAL) was used to analyse the data from projective mapping. Results show that the incomplete design and INDSCAL modelling approach work well for collecting and analyzing manikin and projective mapping data when a large number of respondents are involved. In PM, the consumers organized the emoji according to their perceived valence on the first dimension. Individual differences occurred in how the participants utilized the second dimension, with arousal appearing as one of the relevant criteria. Consumers' latest eating occasion was characterized by a positive valence and intermediate arousal. No pattern linked to the power dimension emerged. The findings may be useful to researchers and practitioners investigating food-related emotions.

Nitrite derivatives react with endogenous precursors forming N-nitrosamines associated with development of colorectal cancer. The present study aims to investigate the formation of N-nitrosamines in sausage during processing and in vitro gastrointestinal digestion after adding sodium nitrite and/or spinach emulsion. The INFOGEST digestion protocol was used to simulate the oral, gastric, and small intestinal phases of digestion, and sodium nitrite was added in the oral phase to mimic the input of nitrite from saliva as it has shown to affect the endogenous formation of N-nitrosamines. The results show that the addition of spinach emulsion, in spite of it being a source of nitrate, did not affect the nitrite content in either batter, sausage, or roasted sausage. The levels of N-nitrosamines increased with the added amount of sodium nitrite, and further formation of some volatile N-nitrosamines was observed during roasting and in vitro digestion. In general, N-nitrosamine levels in the intestinal phase followed the same trend as in the undigested products. The results further indicate that nitrite present in saliva may cause a significant increase in N-nitrosamine levels in the gastrointestinal tract and that bioactive components in spinach may protect against the formation of volatile N-nitrosamines both during roasting and digestion.

Check-all-that-apply (CATA) has become a popular method for obtaining a consumer-based sensory characterization. In most case studies, consumers are also asked to evaluate the set of products according to a liking scale with the aim to identify the key sensory attributes associated with the most liked, or disliked, products. The common approach consists, first, in the identification of consumer segments based on the preference profiles. Thereafter, the analysis of the CATA responses is performed within each segment. Our purpose herein is to investigate different ways to simultaneously identify clusters of preference profiles while taking into account the CATA attributes. These approaches are derived from strategies already proposed by the different co-authors, namely: Fuzzy Clusterwise Regression (FCR), Clustering around Latent Variables (CLV) approach with external data, CLUSCATA-liking and CLV3W. The first two approaches involve the aggregation of the individual CATA data into a contingency table, while the last two ones deal with the combination of liking and CATA data at the individual level. These four strategies are illustrated on the basis of a real case study. Results are compared with respect to cluster stability together with interpretability of liking profiles within each segment. The stability of the results, assessed by bootstrapping, differed according to the strategy used. Moreover, working at the individual level or with combined data lead to a somewhat different segmentation of the panel of consumers.

The effect of a reduced amount of emulsifying salt on the chemical and textural properties of processed cheese was studied. Reducing the amount of emulsifying disodium phosphate salt added resulted in a slight reduction in the pH, lightness and viscosity of the processed cheese. When replacing disodium phosphate with potassium phosphate or potassium citrate alternatives, the processed cheese had slightly higher pH compared with the reference sample. When 15% of sodium in phosphate salt was replaced by the same molar amount of potassium in phosphate form or as citrate salts, the viscosity of the cheese was similar to the reference sample and most of the samples were evaluated as acceptable. However, when 30% of sodium in phosphate form was replaced by either potassium phosphate or citrate a slightly lower viscosity of the processed cheese was indicated and this could be due to the slightly higher pH.

Projective mapping (PM) or napping® has attained much attention in recent literature as a method for fast sensory profiling and measurement of consumer perception. However, little work has been done to understand the consumer’s individual differences in these experiments. In this work, segmentation criteria based on the Procrustes distance are explored. The Procrustes distance can be applied with hierarchical clustering using the Proclustrees method, which consists of doing hierarchical clustering on the pairwise Procrustes distance between consumers. An alternative strategy called sequential clusterwise rotations (SCR) is proposed. SCR extracts clusters by a sequentially partitioning obtained by combining fuzzy clustering techniques and general Procrustes analysis. The methods were tested on simulated and real data and compared with clustering based on MFA results. The simulations show that the MFA approach was outperformed by the other methods when the underlying classes were of same size and there are noise configurations present in the data. For the real data, all methods provided at last one cluster similar to the consensus but differed with respect to the number of clusters identified as well as the interpretation of the clusters. Differences between the methodologies point out the need for external cluster validation in such experiments.

Background: Taste sensitivity has been reported to influence children’s eating behaviour and contribute to their food preferences and intake. This study aimed to investigate the associations between taste sensitivity, eating behaviour, food propensity and BMI (Body Mass Index) in preadolescents. Methods: Preadolescents’ taste sensitivity was measured by detection threshold of sweetness (sucrose), sourness (citric acid), saltiness (sodium chloride), bitterness (caffeine, quinine), and umami (monosodium glutamate). In addition, the Child Eating Behaviour Questionnaire (CEBQ), the Food Propensity Questionnaire (FPQ), and the children’s body weight and height were completed by the parents. A total of 69 child-parent dyads participated (preadolescents mean age =10.9 years). Results: Taste sensitivity to caffeine bitterness was significantly associated with eating behaviour in food responsiveness, emotional overeating, and desire to drink. The preadolescents who were less sensitive to caffeine bitterness had higher food responsiveness scores. Those who were less sensitive to caffeine bitterness and to sweetness had higher emotional overeating scores. In addition, preadolescents who were less sensitive to sourness and bitterness of both caffeine and quinine demonstrated to have higher scores in desire to drink. There was no association between taste sensitivity and FPQ, but significant differences were observed across preadolescents’ BMI for FPQ of dairy food items, indicating higher consumption of low-fat milk in the overweight/obese compared to the normal-weight subjects. There was no significant difference in taste sensitivity according to BMI. Preadolescents’ eating behaviour differed across BMI, demonstrating a positive association between BMI and food approach, and a negative association between BMI and food avoidance. Conclusions: This study contributes to the preliminary understanding of the relationships between taste sensitivity and eating behaviour in preadolescents. The results may be used to develop effective strategies to promote healthy eating practices by considering

Quantitative Descriptive Analysis (QDA) was compared with novel sensory methodology on five high-end loudspeakers using five tracks. The focus of the study was on the ability of different sensory methods to predict quality assessments (liking) made by consumers. Preference mapping indicates that projective mapping (PM) and Check-All-That-Apply (CATA) when performed with experts can provide results comparable to QDA, although slightly less accurate. PM done by consumers is less comparable to QDA. Combinations of the sensory tests were also attempted without any clear improvement of results. Practical applications: The results indicate that it may be possible to replace QDA with more rapid sensory methodology for assessing sensory quality of audio products. This may speed up and simplify product development process. However, further studies will be needed to consolidate the results.

Background The diet plays a major role in shaping gut microbiome composition and function in both humans and animals, and dietary intervention trials are often used to investigate and understand these effects. A plethora of statistical methods for analysing differential abundance of microbial taxa exists, and new methods are constantly being developed, but there is a lack of benchmarking studies and clear consensus on the best multivariate statistical practices. This makes it hard for a biologist to decide which method to use. Results We compared the outcomes of a wide range of ANOVA-like statistical methods to explore to what extent the choice of method affects the biological inferences made. The comparison is based on five published dietary intervention studies representing different subjects and study designs. We found that the methods producing outputs at the community level were in agreement regarding both effect size and statistical significance. However, the methods that provided ranking of operational taxonomic units (OTUs) gave incongruent results, implying that the choice of method is likely to influence the biological interpretations. Conclusions We concluded that inferences at the OTU level should be made with caution, and that a combination of several statistical methods allows to interpret the outcomes with higher confidence and simultaneously account for the limitations of each method.

The involvement of children in sensory evaluation and consumer research continues to increase and has become crucial in the food industry, as children sensory perceptions differ from adults. Research on basic taste sensitivity in children provides contradictory results, with most of the studies not considering the familiarity aspect of the food samples. Familiarity can lead children to memories of the food which are able to influence their taste perception and liking. This study aims to investigate the ability of 10 to 11-year old children in identifying sweetness, saltiness, sourness, and bitterness in unfamiliar food samples. The taste identification data was collected from 98 children using 19 food samples representing the four basic tastes of sweet, sour, salty, and bitter. For each food sample, the children evaluated their familiarity, the basic taste(s) they perceived using the checkall- that-apply (CATA) method and scored their liking. Their basic taste identification ability was investigated by comparing their results to trained panellists as a reference. The food samples were unfamiliar to most of the children (never tasted by 85% of the children on average). Correspondence Analysis (CA) showed that children were able to identify the basic tastes of sweet, sour, salty, and bitter in the unfamiliar foods, with a high congruency to the trained panellists. However, children’s identification ability was lower when combinations of dominant basic tastes occurred. Principal Component Analysis (PCA) demonstrated a positive correlation between the presence of sweet taste and the children’s liking while sour and bitter tastes showed the opposite

Improved quality control and prolonged shelf life are important actions in preventing food waste. To get an overview of the bacterial diversity of fillets from live stored mature Atlantic cod, bacterial isolates were identified before and after storage (air and vacuum) and freezing/thawing. Based on the load of dominating bacteria, the effect of different packaging methods and a short freezing/thawing process on prolonged shelf-life was evaluated (total viable counts, bacteriota, sensory attributes, and volatile components). Hand filleted (strict hygiene) cod fillets had a low initial bacterial load dominated by the spoilage organism Photobacterium, whereas industrially produced fillets had higher bacterial loads and diversity (Pseudomonas, Arthrobacter, Psychrobacter, Shewanella). The identified bacteria after storage in vacuum or air were similar to the initially identified bacteria. Bacteriota analysis showed that a short time freezing/thawing process reduced Photobacterium while modified atmosphere packaging (MAP, 60%CO2/40%O2 or 60%CO2/40%N2) inhibited the growth of important spoilage bacteria (Photobacterium, Shewanella, Pseudomonas) and allowed the growth of Carnobacterium/Carnobacteriaceae and Acinetobacter. Despite being dominated by Photobacterium, fresh fillets stored in MAP 60%CO2/40%N2 demonstrated better sensory quality after 13 days of storage than fillets stored in MAP 60%CO2/40%O2 (dominated by Carnobacterium/Carnobacteriaceae). Carnobacterium spp. or other members of Carnobacteriaceae may therefore be potential spoilage organisms in cod when other spoilage bacteria are reduced or inhibited.

Children generally have a high acceptance for sweetness, but differ in their preferences for the intensity of the taste. This study investigates how food exposure, parental attitudes and behaviours, and children’s taste sensitivity are associated with five-year olds’ preferences for sweetness. Preference data were collected from 135 children at ages four (Mean age: 46.3 months, SD: 3.4, 56% boys) and five years old (Mean age: 57.5 months, SD: 3.3; 58% boys) in a ranking by elimination procedure in the springs of 2015 and 2016. The taste carriers were fruit-flavoured beverages and dark chocolate, both with three levels of sugar content. Quantitative descriptive analysis testified three distinct levels of sweetness in each sample triad. The same children were also tested for sweetness and bitterness taste sensitivity in a paired comparison procedure. The protocols did not require the children to respond verbally, and included elements of gamification in order to engage the children. In addition, a parental questionnaire enquired about exposure to different foods, parental food attitudes and behaviours as well as socio-demographic characteristics. Path modelling using PLS-SEM indicated that differences in children’s preference for sweetness could be explained by differences in exposure to foods, including more frequent exposure to sweet foods and snacks associated with a higher sweet preference. More frequent exposure to fruit and bitter snacks, were associated with a lower sweet preference for the drink and chocolate, respectively. Parental attitudes and behaviours as well as children’s sensitivity to sweetness and bitterness were significantly associated with what foods the children were frequently exposed to, and to their sweetness preferences in beverages and chocolate. Do parents form their children’s sweet preference? The role of parents and taste sensitivity on preferences for sweetness in pre-schoolers

This work explores a new affective approach to projective mapping, based on consumers' choices or preferences. Two sessions, one week apart, were performed with the same consumers, using whole bread as a case study. Overall liking ratings (OL) were gathered in blind conditions and samples were also profiled by a trained panel using generic descriptive analysis. Three projective mapping tests were performed in different scenarios. Consumers' categorization and product descriptions were explored when consumers based their positioning on the products' similarities and differences (analytical approach, “classic napping”) both in blind and informed conditions, and when consumers were focusing on their preference or choice (affective approach). The affective approach to projective mapping successfully revealed consumers' drivers of liking and choice from a holistic perspective, where consumers summarized their main drivers for categorizing products as they would do when choosing in real life situations, based on their preferences.

New aquaculture production systems are evolving for prolong production of Atlantic salmon smolts or post-smolts before stocking in traditional net pens, such as semi-closed containment systems (S-CCS) in sea (Fig. 1) and recirculating aquaculture systems (RAS) on land. The microbiota in these systems can potentially have great impact on the robustness and health of the fish. These two types of aquaculture systems are likely to have different challenges regarding pathogenic invasion due to the different water management, e.g. different treatment of the intake water and different turnover of the water. In this study, we investigated the bacterial microbiota of both water and biofilms in a commercial RAS and in S-CCS in sea during a three months period of post-smolt production. Deep-sequencing of the bacterial 16S rRNA gene (V4) was used for the first time to obtain in depth compositional analysis of microbial communities in commercial scale facilities. Highly diverse communities were detected, with up to 2000 different Operational Taxonomic Units (OTUs) within samples. Both systems were dominated by Proteobacteria with Rhodobacteraceae as the dominating taxa, followed by Bacteroidetes that was dominated by Polaribacter among others. However, the microbiota composition was clearly different between the two aquaculture systems, and between water samples and biofilms. In RAS, it was also shown different microbiota composition with water salinity of 12 vs 22 parts per thousand (ppt). Higher abundance of e.g. Myxococcales and Nitrospiraceae was observed at 12 ppt, which coincided with lower total ammonia nitrogen (TAN) levels. Both taxa were also more abundant in the Moving Bed Bioreactor (MBBR)-biofilms than in water, as well as Planctomyces among others. In S-CCS, clear temporal changes of the microbiota was observed during the production, where potential pathogens like Tenacibaculum , Aliivibrio , Alteromonadaceae and Polaribacter were increasing in the spring time, as well as one unassigned taxa and chloroplast DNA likely from algae. The implication of these potential pathogens on fish health is unknown. A common observation for both RAS and S-CCS was higher abundance of the potential pathogens in the water compared to the biofilms. Further studies on the microbiota in closed-containment aquaculture systems are needed to obtain more knowledge about their impact on post-smolt production performance, welfare and health.

In this paper a general framework is proposed for understanding and analysing more than two consensus components in projective mapping (also known as Napping®) studies. Focus is on how two models, multiple factor analysis (MFA) and individual differences scaling (INDSCAL) based on the weighted Euclidean model (WEM), relate to each other and to the general framework. The stability of the consensus configurations of both methods are compared. The relations between the results of the two methods are investigated using the RV coefficient and an alternative index called SMI which gives equal weight to the axes regardless of the relative size of the singular values. The methods are tested and compared using three datasets and simulations.

Listeria monocytogenes may persist in food production environments and cause listeriosis. In Norway, a product of concern is the traditional and popular fermented fish product “rakfisk”, which is made from freshwater salmonid fish by mild-salting and brine maturation at low temperatures for several months. It is eaten without any heat treatment, and L. monocytogenes, therefore, poses a potential hazard. We investigated the effect of salt and temperature on the growth of L. monocytogenes in rakfisk during the 91 days of maturation. The amounts of organic acids produced during fermentation were too low to inhibit growth of L. monocytogenes. Temperature was clearly the most important parameter for controlling L. monocytogenes. At 7 °C, approximately 2 log growth was observed during the first 14 days of fermentation, and the level of L. monocytogenes thereafter remained constant. At 4 °C, only a little growth potential of the pathogen was recorded. We also investigated the effect of the anti-Listeria bacteriophage P100 on rakfisk with added L. monocytogenes. The phage was introduced to the L. monocytogenes-inoculated fish before fermentation, and an average of 0.9 log reduction was observed throughout the fermentation period. This is the first study of L. monocytogenes behavior in rakfisk and points to possible measures for increasing the product safety.

Recent research suggests that a robot's motors make sounds that can influence users' perception of the robot's characteristics. To more deeply understand users' associations with specific sonic characteristics, we adapted methods from sensory science including Check All That Apply (CATA) questions and Polarized Sensory Positioning (PSP) to tease out small differences in motor sounds in an online survey. These methods are straightforward for untrained people to do in an online setting, mathematically rigorous, and can explore a variety of subtle auditory and perceptual stimuli. We describe how to use these methods, interpret the results with several intuitive visual representations, and show that the results align with a previous study of the same dataset. We close by discussing benefits and limitations of applying these methods to study subtle phenomena in the HCI community.

Many sensory, cognitive, and physiological factors contribute to satiation and satiety responses; sensory and cognitive factors lead to feelings of satiation and short-term satiety. This research aims at understanding how sensory perception and consumer preferences are related to food intake of semisolid foods, using a case study on yogurt with controlled texture variations. Individual differences in food intake and liking were analyzed together with eating rate, to get a holistic picture of the sensory drivers of liking and intake in different groups of consumers. Six yogurts were formulated based on a design of experiment to obtain isocaloric products varying in consistency and particle size. Samples were evaluated by a trained panel via Quantitative Descriptive Analysis (QDA) and Temporal Check-all-that-apply (TCATA). Additionally, 103 consumers ate ad libitum the yogurt samples and rated their liking. Amount eaten was measured by weight and eating rate via video recording. The effect of particle size on intake depended on the thickness of the matrix. Based on Principal Component Analysis (PCA), three groups of consumers were identified that reacted differently to the changes in yogurt texture in terms of amount eaten and liking responses. While for some consumers liking and intake were correlated, others ate more of what they liked less, driven by textural changes in the matrix. Results suggested that different patterns in intake and liking may be related to different eating styles, thus, manipulations on textural properties may reduce the intake for some consumers, but not for all. This work unveils the importance of studying individual differences when measuring food intake, together with static and dynamic sensory drivers for different segments of consumers. In a time where food personalization increases in focus, it seems possible to reformulate food texture to influence consumers expectations and intake, aiming at targeting overeating; however, individual differences need to be better understood to know the implications for different groups of consumers.

Bacterial growth, microbiota and sensory quality of cod loins (farmed Atlantic cod, Gadus morhua) was studied during 15 days of storage (2 °C), packaged in vacuum or in modified atmosphere package (MAP, 60% CO2/40% N2, g/p ratio 1.6/1), with a CO2 emitter pad or a liquid absorbent pad. The objective was to investigate how packaging with CO2 emitter can prolong shelf life in vacuum, and in low headspace MAP. Sensory analysis showed that the initial freshness was better preserved by adding a CO2 emitter in both vacuum and MAP. The MAP had equal antibacterial effect compared to vacuum added CO2 emitter. 16S rDNA sequencing showed that CO2 emitter did not alter the dominant bacterial composition and that Photobacterium sp. dominated all packaging methods. Vacuum packaged samples past shelf life after 7 days of storage, vacuum added a CO2 emitter and MAP after 9 days, and MAP added a CO2 emitter after 13 days.

Temporal Dominance of Sensations (TDS) and Temporal Check-all-that-Apply (TCATA) from three different case studies are compared by means of canonical correlation analysis, orthogonalization and principal component analysis of the vertically unfolded data (which means that the matrices compared have samples* timepoints in the rows and attributes in the columns). The multivariate analyses decompose the datasets into common and distinct components. The results showed that the major part of the variation is common between the two methods for the cases investigated, but that there were subtle differences showing better discrimination for TCATA than TDS. TDS showed a more complex data structure and more unique variation. The unique variation in TDS is, however, difficult to interpret. The methods are more different towards the end of the mastication, this can be explained both by the difficulty of assessors to agree on the dominant attributes at the bolus stage for TDS, and that assessors may forget to unclick attributes in TCATA. This work builds on recent methodological studies on temporal methods that aim to better understand differences among methodologies and ultimately to identify what methods could be better for answering different objectives. Exploring the common and unique variability in TDS and TCATA data – A comparison using canonical correlation and orthogonalization.

BackgroundThis paper presents a strategy for statistical analysis and interpretation of longitudinal intervention effects on bacterial communities. Data from such experiments often suffers from small sample size, high degree of irrelevant variation, and missing data points. Our strategy is a combination of multi-way decomposition methods, multivariate ANOVA, multi-block regression, hierarchical clustering and phylogenetic network graphs. The aim is to provide answers to relevant research questions, which are both statistically valid and easy to interpret.ResultsThe strategy is illustrated by analysing an intervention design where two mice groups were subjected to a treatment that caused inflammation in the intestines. Total microbiota in fecal samples was analysed at five time points, and the clinical end point was the load of colon cancer lesions. By using different combinations of the aforementioned methods, we were able to show that:The treatment had a significant effect on the microbiota, and we have identified clusters of bacteria groups with different time trajectories.Individual differences in the initial microbiota had a large effect on the load of tumors, but not on the formation of early-stage lesions (flat ACFs).The treatment resulted in an increase in Bacteroidaceae, Prevotellaceae and Paraprevotellaceae, and this increase could be associated with the formation of cancer lesions.ConclusionThe results show that by applying several data analytical methods in combination, we are able to view the system from different angles and thereby answer different research questions. We believe that multiway methods and multivariate ANOVA should be used more frequently in the bioinformatics fields, due to their ability to extract meaningful components from data sets with many collinear variables, few samples and a high degree of noise or irrelevant variation.

Segmentation is widely used within consumer research to summarize individual differences, to better understand consumer behavior, and for use in market segmentation. This chapter presents basic methods for unsupervised segmentation such as hierarchical cluster analysis and K means. Methods for validation are discussed, with an emphasis on practical and interpretational aspects. Standard clustering methods are illustrated using example data on liking of extrinsic properties of cured ham.

This chapter explores individual differences in CATA (check-all-that-apply) and PSP (polarized sensory positioning), both of them alternative methods of sensory description with an analytical approach. CATA is an attribute-based method, while in PSP, assessors rate the overall degree of difference to a reference sample. Apart from the validation of the consensus solution and the understanding of the test methods, for CATA it is of particular interest to obtain improved understanding of assessors' response patterns. Analyses in this chapter are based on multiple correspondence analysis and partial least squares for CATA and principal component analysis, multiple factor analysis, and INDSCAL for PSP.

The state-of-the art methodologies for temporal dominance of sensation and temporal check-all-that-apply data are presented with focus on both analysis and graphical tools for interpreting the data. Individual differences on dynamic sensory data are discussed with respect to panel performance, repeatability, and segmentation.

In this chapter, we provide the background and overview of the book. Why is it important to explore individual differences in sensory and consumer sciences? From different perspectives—analytical, affective, cognitive, physiological, situational, and emotional—we explore the implications of the study of individual and group differences in sensory and consumer studies. We explain here the structure of the book, the different data types we will cover, as well as the relations to other books in the market (complementarities and differences).

This chapter is about choice-based conjoint analysis, rank-based tests, and take-away tests. For the former, the focus is on mixed logit models. These are models based on a utility function with additional assumptions on the residuals. It is shown how the individual regression coefficients can be used in connection with principal component analysis to interpret individual differences and to form segments. Segments are related to consumer factors using the PLS regression with dummy output. Rank-based studies are analyzed using simple plotting techniques and PCA. The PCA results can be related to consumer factors as for the mixed logit approach. Other ways of handling ordinal data, such as optimal scaling and the probit model are discussed briefly.

In this chapter, we present the methodological basis for the book and how this relates to aspects of sensory and consumer data such as interactions between assessors and products. These interactions are of particular relevance when studying individual differences. In particular, we present and discuss a number of distinctions and concepts that are important for understanding the relations between the different chapters and methodologies used in the book. A graphical structure to be repeated in each chapter is established for better seeing how the methods relate and deviate from each other. A list of much used statistical methods is provided together with how and where they are used in the different chapters.

This chapter gives an overview of some statistical software that can be applied for the different types of analyses presented in the book. Both tools that require programming and more menu-based software are discussed. The main focus is on XLSTAT, R, and SAS, although most standard software for statistical analysis can be applied for most of the analyses presented in the book.

The focus of this chapter is on analysis of consumer liking data, either total liking or liking for different modalities. Methods for analyzing individual differences per se as well as segmentation are treated. Preference mapping and conjoint are treated in detail together with how to relate individual differences to consumer attributes. Some focus will also be given to methods, which are not so much used in the area like quantile regression for studying quantile distribution and unfolding analysis for revealing consumers' ideal points and products in the same plot. The JAR scale is also discussed as an important tool for obtaining information about possible product improvements.

In this chapter, we present individual differences exploration in two alternative holistic descriptive methods: projective mapping (napping) and sorting. Objectives are to explore group performance, validate the consensus solution, and to improve the understanding of the test methods themselves. Mapping and sorting data, as well as descriptive text data (ultra-flash profiling) are discussed. The main multivariate methods for projective mapping described here are multiple factor analysis, generalized Procrustes analysis, and INDSCAL. How to obtain consensus configurations and how to analyze individual differences, as well as segmentation and estimating relations to consumer factors are covered. For sorting data, multidimensional scaling and DISTATIS are discussed.

TDS describes the evolution of the dominant sensory attributes during consumption. Dominance can be assessed as the sensation that captures the attention, the most striking, or the new sensation that pops up, but not necessarily the most intense. This wide definition implies that individual assessors within a panel might assess dominance differently, and even the same assessor could be using different strategies for determining the dominant attribute the same product evaluation. In this context, the aim of the present work was to explore how trained assessors and consumers conceptualize dominance and how the different interpretations and definitions of dominance might influence results of a TDS test. Two studies were performed, one study with a highly trained panel of 10 assessors and another study with 108 consumers. Trained assessors evaluated three bread samples via TDS and their conceptualization of dominance was explored through an immediate retrospective verbalization task. Consumers evaluated their temporal perception of a commercial milk chocolate sample and answered a series of open-ended questions. Results showed that dominance is a complex construct that is not related to a single aspect of sensory perception, and that different conceptualizations of dominance within a panel can hinder an accurate interpretation of results from TDS studies. Various aspects of dominance are highlighted and discussed: how attributes are selected, which are the drivers of transitions between dominant attributes, how the competitive effects of attributes and modalities are manifested, how some phenomena like dumping or dithering could happen at some stages and why. Practitioners are advised to ensure that their interpretation of TDS data is made within the context of the dominance definition they instructed assessors to use. Implications of the results for the application of TDS with trained assessors and consumers are discussed.

Projective mapping (PM), one of the most holistic product profiling methods in approach, is increasingly being used to uncover consumers' perception of products and packages. Assessors rely on a process of synthesis for evaluating product information, which would determine the relative importance of the perceived characteristics they use for mapping them. Individual differences are expected, as participants are not instructed on the characteristics to consider for evaluating the degree of difference among samples, generating different perceptual spaces. Individual differences in cognitive style can affect synthesis processes and thus their perception of similarities and differences among samples. In this study, the influence of the cognitive style in the results of PM was explored. Two consumer studies were performed, one aimed at describing intrinsic sensory characteristics of chocolate flavoured milk and the other one looking into extrinsic (package only) of blueberry yogurts. Consumers completed the wholistic-analytic module of the extended Verbal Imagery Cognitive Styles Test & Extended Cognitive Style Analysis-Wholistic Analytic Test, to characterize their cognitive style. Differences between wholistic and analytic consumers in how they evaluated samples using projective mapping were found in both studies. Analytics separated the samples more in the PM perceptual space than wholistic consumers, showing more discriminating abilities. This may come from a deeper analysis of the samples, both from intrinsic and extrinsic point of views. From a sensory perspective (intrinsic), analytic consumers relied on more sensory characteristics, while wholistic mainly discriminated samples according to sweetness and bitterness/chocolate flavour. In the extrinsic study however, even if analytic consumers discriminated more between packs, they described the products using similar words in the descriptive step. One important recommendation coming from this study is the need to consider higher dimensions in the interpretation of projective mapping tasks, as the first dimensions could underestimate the complexity of the perceptual space; currently, most applications of PM consider two dimensions only, which may not uncover the perception of specific groups of consumers.

Different strategies for investigating individual differences among consumers using choice experiments are compared. The paper is based on a consumer study of iced coffee in Norway. Consumers (n = 102) performed a choice task of twenty different iced coffee profiles varying in coffee type, production origin, calorie content and price following an orthogonal design. Consumer factors, such as socio-demographics, attitudes and habits, were also collected. Choice data will be analysed using two different clustering strategies. Strategy one is the most classical approach called Latent Class Logit (LCL) model, while Strategy two uses Mixed Logit (ML) model combined with Principal Component Analysis (PCA) for visual segmentation or with automatic clustering detection using Fuzzy C Means clustering (FCM). The clusters obtained can be interpreted using external consumer factors by using the Partial Least Square – Discrimination Analysis (PLS-DA) model. The different approaches are compared in terms of data analysis methodologies, modelling, outcomes, interpretation, flexibility, practical issues and user friendliness.

The effect of extrusion of barley and oat on the fecal microbiota and the formation of SCFA was evaluated using growing pigs as model system. The pigs were fed a diet containing either whole grain barley (BU), oat groat (OU), or their respective extruded samples (BE and OE). 454 pyrosequencing showed that the fecal microbiota of growing pigs was affected by both extrusion and grain type. Extruded grain resulted in lower bacterial diversity and enrichment in operational taxonomic units (OTUs) affiliated with members of the Streptococcus, Blautia and Bulleidia genera, while untreated grain showed enrichment in OTUs affiliated with members of the Bifidobacterium and Lactobacillus genera, and the butyrate-producing bacteria Butyricicoccus, Roseburia, Coprococcus and Pseudobutyrivibrio. Untreated grain resulted in a significant increase of n-butyric, i-valeric and n-valeric acid, which correlated with an increase of Bifidobacterium and Lactobacillus. This is the first study showing that cereal extrusion affects the microbiota composition and diversity towards a state generally thought to be less beneficial for health, as well as less amounts of beneficial butyric acid.