Nudging product choices: The effect of position change on snack bar choice

The influence of product position in a row of three similar snacks with varying calorie contents was examined in a sample of 120 students (equal numbers of males and females). Three equally sized, real cereal snack bars were arranged on a vendor’s tray in three identical boxes. Two conditions were used. In the control condition, the three boxes of snack bars were positioned from left to right in ascending order of calorie content (apple/lowest calorie content = left position; apple-chocolate/high calorie content = middle position; coco-chocolate/highest calorie content = right position). In the experimental condition (nudged group), the left and middle box positions were exchanged (apple-chocolate/high calorie content = left position; apple/lowest calorie content = middle position; and coco-chocolate/highest calorie content = right position). There was a significant effect of position on participants’ snack bar selections (χ²₍₂₎ = 14.953, p = 0.001). When the apple bar was positioned on the left, it was selected 13.3% of the time (8/60), and when it was positioned in the middle, it was selected 36.3% of the time (22/60). There was no gender effect (χ²₍₂₎ = 0.713, p = 0.70). The apple bar with lowest calorie content was selected almost three times more often when it was placed in the middle than when it was placed on the left. Changing the physical placement of the snack improved snack choices. Rearranging snacks on shelves and checkout counters in grocery stores or vending machines in schools might be an easy, inexpensive and effective intervention measure to improve consumers’ snack choices.     

Relating consumer and trained panels’ discriminative sensitivities using vanilla flavored ice cream as a medium

This research investigated the possibility of uncovering a relationship between the sensitivities of trained and consumer panels in three experiments. In Experiment I, five studies were conducted using vanilla flavored ice cream. In each study, two ice cream samples differing in formulation and/or their manufacturing process were used. They were compared by both panels using same–different tests with sureness judgments (degree of difference methodology). Using the appropriate probabilistic Thurstonian model, d′ values, a measure of the underlying sensory difference perceived between the products, were calculated and the underlying relationship between the two panels’ sensitivities uncovered. An additional study was then conducted (Experiment II). A new pair of ice creams differing in fat content was first evaluated by the trained panel. Based on the estimated d′ value (trained panel’s measured d′ = 2.69), the corresponding consumer d′ value was predicted using the relationship uncovered in Part I (consumer panel’s predicted d′ = 1.54). The same pair of ice creams was then evaluated by the consumer panel. The measured d′ value for the consumers was almost identical to that predicted by the uncovered relationship (consumer panel’s measured d′ = 1.56). Along with the discrimination component of these studies, paired preference tests were conducted (Experiment III) in order to study a link between perceived difference and expressed preference. The results give an indication of when a perceived difference might start translating into a change in acceptability of the original product. These results indicate the potential of such an approach to predict consumers’ perceptions from an in-house semi-trained or trained panel, providing a useful predictive tool and a means of reducing repetitive and costly consumer testing.     

Short-term appetite-reducing effects of a low-fat dairy product enriched with protein and fibre

The objectives of this work were to investigate short-term appetite-reducing effects of an innovative low-fat yogurt enriched with protein (8 g/serving) and fibre (2.6–2.9 g/serving). Two studies were conducted using randomised cross-over designs. Healthy women consumed a mid-morning snack consisting of either the test or the control yogurt product (Study 1, n = 24: iso-energetic, not iso-weight conditions; Study 2, n = 121: iso-weight, not iso-energetic conditions) under laboratory conditions. Subjective appetite ratings (of hunger, fullness, desire to eat and prospective consumption) were recorded throughout the morning; sensory and hedonic ratings were also collected. In Study 2, two hours after consumption of the dairy snack, subsequent food intake at lunch was also measured. The test product reduced subjective appetite compared to the control (all ratings, P < 0.05). Energy intake at lunch was reduced by 274 kJ after the test compared to the control (P < 0.001). These two studies demonstrated that a low-fat dairy product enriched with protein and fibre can significantly reduce short-term appetite.     

Associations between nutritional properties of food and consumer perceptions related to weight management

Consumer perceptions of food (for example, how filling or healthy) influence eating behaviour and appetite control. Therefore approaches to understand the global nutritional attributes of foods that predict the strength of consumer perceptions are of academic and commercial interest. The current research describes the development of a flexible platform for systematically mapping the global nutritional attributes of foods (both objective and perceived) to consumer perceptions of those foods. The platform consists of a database of standardised UK food images (currently n = 300), linked to a catalogue of detailed perceptual, nutritional, sensory, cost, and psychological information (‘nutritional attributes’). The platform also incorporates demographic and psychometric questionnaires to examine the importance of nutritional attributes on consumer perceptions within or between relevant target groups. In the current study, the platform was applied to a sample of dieting and non-dieting British men and women (n = 887) to examine the global attributes of a subset of foods (n = 75) and their association with successful weight management (i.e. supportive of weight loss, weight loss maintenance or prevention of weight gain). Generalised linear models identified energy density, cost (£/kcal), perceived energy content and satiating capacity as the main nutritional attributes underlying dieters’ and non-dieters’ perception of successful weight management food. Additionally, pleasantness, and desire not to (over) eat were uniquely associated with dieters’ perception of food as good for weight management; pleasantness was positively associated with weight management and desire to eat was negatively associated with weight management. Therefore, global nutritional attributes of foods can predict and distinguish the extent consumers’ perceive a food to be related to successful weight management. This platform will be extended to increase the variety of foods and specificity of nutritional attributes in the database suitable for a range of commercial, academic or clinical research applications.     

Learning to associate compatible and incompatible pictures with food and non-food odours,within a stimulus equivalence paradigm

Within consumer research, it is acknowledged that influential and perhaps unconscious associations to products exist, which require indirect as well as direct methods of investigation. We examine the potential usefulness of one such indirect method, an application of the stimulus equivalence matching-to-sample paradigm [Sidman, M. (1971). Reading and auditory–visual equivalences. Journal of Speech and Hearing Research, 14, 5–13].Two experiments are reported (n = 15, n = 20). Both used three, 3-membered stimulus sets: A (food and non-food odours); B (nonsense syllables); and C (pictures), two of which were either ‘compatible’ or ‘incompatible’ with the corresponding items in the A set. Each participant took part in both ‘compatible’ and ‘incompatible’ conditions. First, (A → B), participants were trained to choose one of the three nonsense syllables when presented with one of the odours. Second, (B → C), those who had learned the first task (n = 10, n = 14) were trained to choose one of the three pictures when presented with one of the nonsense syllables, and finally, in a test phase (C → A), to choose one of the three odours when presented with one of the pictures. In both experiments, B → C trials to criterion and response times were significantly greater in the ‘incompatible’ condition, and the error structure differed between conditions. In other phases, no consistent inter-condition differences were found. We discuss the use of this paradigm in consumer research on odours and tastes as a very indirect way of measuring pre-existing associations.     

Effects of flour free lipids on textural and cooking qualities of Chinese noodles

The relationships between textural and cooking qualities of Chinese noodles and flour lipids were investigated. Removal of free lipids (FL) or excess FL caused significant decreases in hardness and cohesiveness of noodles. The highest hardness and cohesiveness of noodles were obtained at certain FL levels (1.84 and 1.24 g/100 g flour, respectively). Tensile strength and breaking length of noodles both reached the highest values when FL content in the flour was adjusted to about half of the original level. A good correlation was found between cohesiveness and cooking loss of noodles (r = ?0.967). Hardness and cohesiveness of cooked noodles increased linearly with the increase of polar lipids (PL) relative proportion of FL (r = 0.939 and 0.900, respectively). Entire replacement of PL with nonpolar lipids in flour led to a significant decrease in springiness of noodles. These results suggest that PL play an important role in obtaining strong noodle texture.     

Effect of varying salt and fat levels on the sensory and physiochemical quality of frankfurters

The sensory and physiochemical properties of frankfurters with varying fat and salt levels were investigated. Twenty frankfurter formulations were produced with varying concentrations of fat (10%, 15%, 20%, 25% w/w) and salt (1%, 1.5%, 2%, 2.5%, 3% w/w). Frankfurters were assessed instrumentally for colour, moisture, fat, cooking loss and texture profile analysis. Consumers (n = 25) evaluated each product in duplicate for colour, coarseness, tenderness, juiciness, salt taste, meat flavour, off-flavour and overall acceptability using a hedonic scale. Salt levels below 1.5% were shown to have a negative effect on consumer acceptability, with 2.5% salt concentration being the most accepted (P < 0.001) by consumers. However, frankfurters containing the lower fat levels 10% and 15% fat with higher salt levels (2.5–3%) were significantly the most acceptable variants to consumers. Samples containing less fat and salt were found to be tougher, less juicy and had greater cooking losses. Thus salt perception is very important for consumer acceptability, but fat levels can be potentially reduced without significantly affecting overall acceptability.     

A systematic review and meta-analysis of the effectiveness of biosecurity and vaccination in reducing Salmonella spp. in broiler chickens

Our objective was to estimate the effectiveness of vaccination and biosecurity on the prevalence of Salmonella spp. in broiler chickens using systematic review and meta-analysis. A comprehensive search of the global primary literature was conducted in: Current Contents (1999–2009), Agricola (1924–2009), MEDLINE (1860–2009), Scopus (1960–2009), CAB (1913–2009), and Centre for Agricultural Bioscience Global Health (1971–2009). The search algorithm was (Salmonell*) AND (chicken* OR chick* OR poultry* OR broiler* OR gallus*). Additional studies were identified by contacting five topic experts and hand-scanning bibliographies of recent review articles and a recently published textbook. Studies were included if they were English language and investigated the effects of vaccination and biosecurity on the prevalence of Salmonella spp. in broiler chickens. All study design types were included. Data extraction and methodological assessment were conducted by two reviewers independently. All meta-analyses were based on random-effects models. For biosecurity, sixteen challenge studies (n = 137 treatment-control comparisons) and one controlled study (n = 2) met the inclusion criteria. Significant heterogeneity (Cochran's Q-statistic, p < 0.001) was observed among biosecurity challenge studies examining hydrogen peroxide or polyhexamethylenebiguanide hydrochloride applied to hatching eggs, making it inappropriate to present a summary effects measure. For vaccination, 19 challenge studies (n = 226) and three controlled studies (n = 10) met the inclusion criteria. Among live Salmonella Typhimurium vaccine challenge studies heterogeneity was not significant (p = 0.138). Vaccination with a live Salmonella Typhimurium reduced the risk of Salmonella cecal colonization in the treated broiler group by 35 out of 1000 broilers when compared to the control group (OR = 0.21; 95% CI = 0.06–0.77) and this effect was significant (p = 0.018). One biosecurity study (n = 2 treatment-control comparisons) and three vaccination studies (n = 10) were conducted in a commercial setting. The two included studies in the vaccination meta-analysis were both conducted at research facilities. The live Salmonella Typhimurium vaccine showed the most promise in reducing the prevalence of Salmonella in broiler ceca. However, the meta-analysis included few studies, and these studies challenged the birds with different serotypes. We recommend that more large-scale randomized, blinded trials be conducted with a live Salmonella Typhimurium vaccine on commercial farms.     

Physicochemical changes in a model protein bar during storage

High-protein snack bars (protein bars) contain high-quality protein, sugars and other low molecular weight polyhydroxy compounds (PHCs), high-energy confectionary fats, and a minimum of water (water activity ? 0.65). The consequence of the intimate mixing of these components in protein bars is that they can react together, creating sensory characteristics that are unacceptable to consumers. This study examined the changes occurring in a model protein bar during storage for 50 days at 20 °C.Over this time, fracture stress increased from 20.1 ± 1.8 to 201 ± 75 Pa at a rate that decreased slightly over time. ¹H nuclear magnetic resonance (NMR) showed that the molecular mobility of PHCs decreased dramatically over the first 5 days as the batter set into a solid bar. Over the first 17 h after manufacturing, protein particles became more clustered, and soluble protein appeared to precipitate, as shown by confocal microscopy. Reactive lysine fell 38% in the first 10 days of storage and was approximately constant thereafter. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) showed little change in protein molecular weights. Following the initial ‘setting’ phase of 5–10 days, fracture stress continued to increase and the molecular mobility of PHCs decreased. Changes in PHC molecular mobility were consistent with glucose crystallisation. Chemical changes were minimal during this phase, which suggests that chemical reactions play little part in the hardening of protein bars and that changes in molecular mobility and changes in microstructure driven by moisture migration may be more important.     

The demographics of neophobia in a large commercial US sample

Neophobia was measured with two large (n = 1567 and n = 6843) commercial samples of US consumers on a 5-point Food Neophobia Scale. Results were compared with demographic data collected in other samples in the US and in other countries. Gender effects remain unclear; while neophobia appears to increase with age, while decreasing with increasing education and with increasing income. Results are explained by an increased exposure to foods with increasing income and education.     

Effects of interval length between tasting sessions and sweetener level on long-term acceptability of novel green tea drinks

The objective of this study was to investigate the effects of the interval length between sessions (1-day vs. 3-day), the sweetener level (Optimal (OP) vs. Low (LO)), and the number of stimuli (one vs. two) on long-term acceptability of a novel green tea drink. Two consumer groups (N = 80) rated their liking of two drinks (OP and LO) while another 4 consumer groups (N = 162) rated only one drink over 10 sessions at either 1-day or 3-day intervals. Repeated consumption led to an overall increase in liking of the novel drink even though the patterns of increase were different according to the sweetener level and the interval length. Higher sweetener level and shorter interval length might contribute to increase in liking score during the earlier sessions and stable liking during the later sessions for novel green tea drink.     

Effects of an evoked refreshing consumption context on hedonic responses to apple juice measured using best–worst scaling and the 9-pt hedonic category scale

Awareness of the need to consider a product’s consumption context when measuring consumer hedonic response of a product is increasing among consumer sensory researchers. This study investigated the effects of evoking a consumption context using a written scenario on hedonic response measured using best–worst scaling and the 9-pt hedonic category scale. Hedonic responses for four apple juices with relatively large sensory differences were compared when measured in the evoked context ‘when having something refreshing to drink’ using best–worst hedonic scaling (n = 65) and the 9-pt hedonic scale (n = 48). Best–worst scaling discriminated between the four apple juices when a refreshing context was evoked (p < 0.01), while the juices were equally liked using the 9-point scale (p = 0.41) when the same context was evoked. Consumers perceived best–worst scaling to be more difficult than the 9-pt scale, however there was no difference between the two methods for consumers perceived accuracy of their liking information. The present study highlights that the effect of an evoked context on hedonic response may not be universal for hedonic methods. Further research is needed to understand the effect of evoking context on the liking of products, and to determine whether this measure reflects product liking in an actual consumption context.     

The consumer acceptance of novel vegetable-enriched bread products as a potential vehicle to increase vegetable consumption

Currently UK fruit and vegetable intakes are below recommendations. Bread is a staple food consumed by approximately 95% of adults in western countries. In addition, bread provides an ideal matrix by which functionality can be delivered to the consumer in an accepted and convenient food. Therefore, enriching bread with vegetables may be an effective strategy to increase vegetable consumption. This study evaluated bread enriched with red beetroot, carrot with coriander, red pepper with tomato or white beetroot (40 g vegetable per 100 g) compared to white control bread (0 g vegetable) for consumer acceptance. Consumers (n = 120) rated their liking of the breads overall, as well as their liking of appearance, flavour and texture using nine-point hedonic scales. Product replacement and purchase intent of the breads were rated using five-point scales. The effect of providing consumers with health information about the breads was also evaluated. There were significant differences in overall liking (P < 0.0001), as well as liking of appearance (P < 0.0001), flavour (P = 0.0002) and texture (P = 0.04), between the breads. However, the significant differences resulted from the red beetroot bread which was significantly (P < 0.05) less liked compared to control bread. There were no significant differences in overall liking between any of the other vegetable-enriched breads compared with the control bread (no vegetable inclusion). The provision of health information about the breads did not increase consumer liking of the vegetable-enriched breads. In conclusion, this study demonstrated that vegetable-enriched bread appeared to be an acceptable strategy to increase vegetable intake, however, liking depended on vegetable type.     

Sensory profile,acceptability, and their relationship for diabetic/reduced calorie chocolates

The purpose of this study was to determine the sensory properties and acceptability of lab developed prototypes of conventional, diabetic (with no sugar), and diabetic/reduced calorie milk chocolates (no sugar and 25% calorie reduction) with high-intensity sweeteners, sucralose and stevioside, and partial fat replacement with whey protein concentrate (WPC). PLS was performed in order to relate sensory properties and consumer acceptability and to determine drivers of liking and disliking. There was no difference between conventional, diabetic and diabetic/reduced calorie milk chocolates for brightness, cocoa aroma, cocoa butter aroma, and cocoa flavor (p > 0.05). Acceptability was higher for sucrose substitution by sucralose than by stevioside and partial fat replacement reduced acceptability of flavor even more (p ? 0.05). Crucial attributes which determine consumer acceptability in samples are sweet aroma, melting rate, and sweetness, whereas bitterness, bitter aftertaste, adherence, and sandiness were drivers of disliking.     

Sensory profiles and consumer acceptability of a range of sugar-reduced products on the UK market

Current UK intake of non-milk extrinsic sugars (NMES) is above recommendations. Reducing the sugar content of processed high sugar foods through reformulation is one option for reducing consumption of NMES at a population level. However, reformulation can alter the sensory attributes of food products and influence consumer liking. This study evaluated consumer acceptance of a selection of products that are commercially-available in the UK; these included regular and sugar-reduced baked beans, strawberry jam, milk chocolate, cola and cranberry & raspberry juice. Sweeteners were present in the reformulated chocolate (maltitol), cola (aspartame and acesulfame-K) and juice (sucralose) samples. Healthy, non-smoking consumers (n = 116; 55 men, 61 women, age: 33 ± 9 years; BMI: 25.7 ± 4.6 kg/m²) rated the products for overall liking and on liking of appearance, flavor and texture using a nine-point hedonic scale. There were significant differences between standard and reduced sugar products in consumers' overall liking and on liking of each modality (appearance, flavor and texture; all P < 0.0001). For overall liking, only the regular beans and cola were significantly more liked than their reformulated counterparts (P < 0.0001). Cluster analysis identified three consumer clusters that were representative of different patterns of consumer liking. For the largest cluster (cluster 3: 45%), there was a significant difference in mean liking scores across all products, except jam. Differences in liking were predominantly driven by sweet taste in 2 out of 3 clusters. The current research has demonstrated that a high proportion of consumers prefer conventional products over sugar-reduced products across a wide range of product types (45%) or across selected products (27%), when tasted unbranded, and so there is room for further optimization of commercial reduced sugar products that were evaluated in the current study. Future work should evaluate strategies to facilitate compliance to dietary recommendations on NMES and free sugars, such as the impact of sugar-reduced food exposure on their acceptance.     

The effect of brand names on flavor perception and consumption in restrained and unrestrained eaters

In an increasingly obesogenic food environment, making healthful food decisions can be difficult. Because consumers are often bombarded with excessive information about foods they often rely on simple heuristics to decide whether to purchase or consume a food. In the present study we tested females who were either restrained (n = 33) or unrestrained (n = 33) to determine whether their sensory perception and intake of a food would be affected by brand information. Participants were provided with in an ad libitum snack of cookies which was labeled with a brand typically associated with healthful snacks or a brand associated with unhealthful snacks. Results indicated that all participants rated the cookies with the healthful brand label as more satisfying and as having a better taste and flavor. Furthermore, restrained eaters consumed more of the healthful brand than the unhealthful brand, whereas unrestrained eaters’ consumption did not differ. Thus it appears that food-related beliefs do influence consumers’ intake, especially that of restrained eaters. Further research is warranted to investigate these beliefs in order to improve recommendations for healthful eating in a society facing an increased prevalence of overeating and obesity.     

The influence of sensory and packaging cues on both liking and emotional,abstract and functional conceptualisations

Thomson et al. (2010) have argued that the key to unlocking the mystery of consumer choice is to assess and measure the ‘meanings’ consumers attach in their minds to the product, which can be referred to as conceptualisations. Conceptualisations can be reduced to three broad categories: emotional, abstract and functional (Thomson et al., 2010). However, little data is available to understand how sensory attributes and packaging cues of a product evoke conceptualisations. The objectives of this study were to: (i) derive emotional, abstract and functional conceptualisation lexicons for a commercial product category; (ii) measure how these conceptualisations, and liking, change across blind, package and informed conditions; (iii) test the hypothesis that abstract/functional conceptualisations are more strongly associated with extrinsic product cues; and, finally (iv) explore the effect of package derived conceptualisations on liking and conceptualisations scores derived from product consumption experience. A lexicon to describe the conceptualisations associated with commercial blackcurrant squash was developed by consumers (n = 29). A larger group of consumers (n = 100) were then asked to assess their conceptual response to eleven squashes under three conditions: blind, pack and informed using Check-All-That-Apply (CATA). The findings of the study revealed that intrinsic product characteristics have more association with emotions whereas extrinsic product characteristics were more associated with abstract/functional conceptualizations. In addition, the results of the study also showed how package derived conceptualisations influenced the liking score and conceptualisations frequencies between blind and informed conditions in a small number of products. However, a more systematic experimental design is needed to further investigate the hypotheses that follow from the results obtained in this study.     

Country of origin or EU/non-EU labelling of beef? Comparing structural reliability and validity of discrete choice experiments for measurement of consumer preferences for origin and extrinsic quality cues

The use of food labels and packaging information on place of origin and credence quality has increased, but it is still unclear how such information relates to consumer decisions and choices concerning the relative valuation of attributes. Valid measurement methods are needed to assess the importance attributed by the public to such information, but also to inform the industry about market demand. Discrete choice experiments (CEs) are frequently used to assess consumer preferences for food attributes. However, suitable methods are needed to reveal the probabilistic nature of preference data, so that heterogeneity can be explicitly accounted for. An R-index measure was modelled to account for choice probabilities in this study. Two surveys of Swedish residents, without (n = 506) and with (n = 278) a price vector, compared attribute importance for origin and extrinsic quality labelling of beef in CEs. Problems of structural reliability owing to unstable associations in attribute importance between formats were supported, but on levels rather than orderings. The R-index analysis of CE data revealed violations of attribute transitivity and dominance. Extending CE analysis to include choice probabilities may be useful for consumer profiling and for optimisation of product information. Labels with specific country-of-origin information instead of a wider EU/non-EU designation were the most determining attribute in this study.