A longitudinal comparison of two salt reduction strategies: Acceptability of a low sodium food depends on the consumer

In their 2010 publication, Strategies to Reduce Sodium Intake in the United States, the Institute of Medicine suggested the FDA mandate salt reduction at the food industry level via a strategy of gradual, step-wise decline. The objective of this study was to compare the acceptability trajectories of a gradual to an abrupt salt reduction strategy of a high sodium food, and to determine if these trajectories were impacted by an individual’s hedonic sensitivity to salt and/or motivation to reduce dietary salt intake. Eighty-three subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. At the initial and final taste tests, subjects indicated liking of tomato juice at four salt concentrations ranging from 136 mg sodium/serving (low sodium) to 640 mg sodium/serving (comparable to a commercially available product). To create two groups for the 16-week study, subjects were balanced for 6-n-propylthiouracil sensitivity, motivation to reduce dietary salt intake, and hedonic sensitivity to salt (the difference in liking between the highest and lowest salt concentrations in tomato juice served at the initial taste test). One group received juice abruptly reduced in salt at week 4 to a target low sodium level; the second group received juice gradually reduced in salt via difference threshold steps determined in a preliminary study (cumulating reductions of 12% each), to reach the target at week 14. We observed no overall difference in liking for low sodium juice at the end of the study as a result of salt reduction strategy; however, the trajectory of liking ratings over time differed between groups. Gradual salt reduction was more effective than the abrupt salt reduction because the abrupt reduction was accompanied by a large immediate drop in liking whereas the gradual reduction better maintained acceptability throughout the process. Subjects with low hedonic sensitivity responded favorably to both salt reduction strategies and would likely have no difficulty in adjusting to the taste of reduced salt foods. However, subjects with high hedonic sensitivity disliked reduced salt juice at some point during the study, regardless of strategy, and would likely have difficulty in adjusting to the taste of reduced salt foods.     

Sugar reduction in probiotic chocolate-flavored milk: Impact on dynamic sensory profile and liking

Reducing the sugar content of processed products has been claimed to be one of the most efficient strategies for decreasing sugar intake. The present work aimed at studying the influence of sugar reduction on the dynamic sensory profile and consumers' liking of probiotic chocolate-flavored milks using a novel temporal methodology, and to evaluate two alternatives (vanilla flavor and thaumatin) to attenuate the sensory changes caused by sugar reduction. Probiotic chocolate-flavored milks were formulated with different reductions in added sugar (0, 20, 40 and 60%). Vanilla flavor and thaumatin were added to the sugar-reduced samples at two concentrations. Samples were evaluated by trained assessors using Temporal check-all-that-apply (TCATA). Additionally, consumers evaluated the dynamic sensory profile of a subset of the samples using TCATA and indicated their overall liking using a 9-point hedonic scale. Results from the present work showed that the main effect of sugar reduction on the dynamic sensory profile of the probiotic chocolate-flavored milks was related to changes in sweetness, bitterness and thickness. A reduction in added sugar of 20% led to changes in sweetness intensity, which were perceived by both trained assessors and consumers. However, consumers' liking was not significantly affected by sugar reduction up to 40%. The addition of vanilla flavor at suprathreshold concentrations was not efficient in increasing sweetness perception in chocolate-flavored milks with the lowest sugar reduction percentage, suggesting that it may not be a feasible alternative for reducing sugar in this product category. These results suggest that in many situations sugar content of food products could be decreased without a relevant impact on consumers' sensory and hedonic perception.     

A consumer-based approach to salt reduction: Case study with bread

In recent years high sodium intake has raised growing concern worldwide. A widespread reduction of salt concentration in processed foods has been claimed as one of the most effective strategies to achieve a short-term impact on global health. However, one of the major challenges in reducing salt in food products is its potential negative impact on consumer perception. For this reason, gradual salt reduction has been recommended. In this context, the aim of the present work was to present a consumer-based approach to salt reduction, using bread as case study. Two consumer studies with a total of 303 consumers were carried out. In the first study, four sequential difference thresholds were determined through paired-comparison tests, starting at a salt concentration of 2%. In the second study, 99 consumers performed a two-bite evaluation of their sensory and hedonic perception of five bread samples: a control bread containing 2% salt and four samples with reduced salt content according to the difference thresholds determined in the first study. Survival analysis was used to determine average difference thresholds, which ranged from 9.4% to 14.3% of the salt concentration of the control bread. Results showed that salt concentration significantly influenced consumer overall liking of the bread samples. However, large heterogeneity was found in consumer hedonic reaction towards salt reduction: two groups of consumers with different preference and hedonic sensitivity to salt reduction were found. Results from the present work confirm that cumulative series of small salt reductions may be a feasible strategy for reducing the sodium content of bread without affecting consumer hedonic perception and stress the importance of considering consumer perception in the design of gradual salt reduction programmes.     

A new approach to measuring Overall Liking with the Many-Facet Rasch Model

The 9-point hedonic scale is the most common hedonic rating scale used to provide an assessment of overall liking. Studies have shown that consumer judgements of overall liking could be influenced by their ratings of the liking of flavour, texture, aroma or appearance. However, this is not directly taken into account when using the holistic variable of overall liking. A new approach is proposed for measuring overall liking that is firstly based on initially considering what sensory characteristics (attributes or modalities) defines the latent sensory construct of OVERALL LIKING. The aim of this study was to develop a single measure of Overall Liking that incorporates the relative importance of liking ratings from different sensory characteristics by applying a Many-Facet Rasch model to produce interval-scaled estimates of Overall Liking. A homogeneity test found significant differences (p < 0.01) between the Rasch means estimates of the cured 10 hams that were evaluated by a consumer panel (n = 90), with the two different definitions of the Rasch measure of Overall Liking. No significant differences were found when comparing Rasch measures with raw scores using an intrablock BIB ANOVA and Durbin test. The degree of Relevance, shown on a Many-Facet Wright map, indicated the extent which a variable contributed to the measure of Overall Liking. Of the 10 sensory attributes used for the Individual Attribute Measure, Hardness and Juiciness contributed the most, while Sweetness and Typical Flavour contributed the least. However, the modalities used in rating the Likings of Overall Flavour, Texture, Aroma and Appearance contributed almost to the same extent to Overall Liking in the Total Attribute Measure. The Wright Map also showed that the categories on the 9-point hedonic scale were unequally spaced and the distance between them became increasingly larger the further away from the central category of ‘Neither like nor dislike’.     

Dynamics of food preferences: a case study with chewing gums

The dynamics of food perception is critical in sensory science. However, although much research deals with time–intensity measurement as a tool for analytical sensory evaluation, it is striking that almost no published research investigates the dynamics of hedonic responses. Here we studied how consumers scored mint flavored sugar-free gums when the test duration varied. Six coated dragée-like gums from the French market were tested by each consumer according to three test conditions: 1 min of chewing, 5 min and half-an-hour. One and five minute tests took place in the sensory lab evaluation booths whereas consumers were free to move about for the 30 min modality. All consumers thus participated to a total of 18 sessions. Our main finding is that the average liking varies with the test duration but that this variation differs for the six products in a way that one of the initially least liked products becomes the most liked when it is chewed during 30 min. Also, the individual liking patterns and the resulting consumer segmentation varied widely across the three test conditions. Additionally, a Flash profile was performed with experienced subjects in an attempt to relate the observed differences in liking to the gum sensory characteristics. Trigeminal-related sensations seem to play an important role in these changes. Clearly such aspects are to be taken into account for new product development and market analysis. This kind of concerns may be even more challenging for hedonic evaluation of many non-food products.     

Studying the influence of package shape and colour on consumer expectations of milk desserts using word association and conjoint analysis

Food packaging plays a major role in attracting consumer attention and generating sensory and hedonic expectations; which could affect their product perception and purchase decisions. In the present study word association and conjoint analysis were used to study the influence of package shape and colour on consumer expectations of milk desserts. Six images of milk dessert packages with different colour and shape were presented to 105 consumers, who were asked to complete a word association task and to score their expected liking and willingness to purchase the desserts. Both package shape and colour affected consumers expected liking scores and their sensory expectations regarding the desserts. Consumers associations were mainly related to sensory characteristics. Both methodologies provided an interesting insight on the consumer’s expectations generated by the packages and could be useful in order to design packages which create appropriate expectations regarding the product.     

Preference for salt in a food may be alterable without a low sodium diet

In response to current efforts to reduce population-wide dietary salt intake, the objective of this study was to determine whether liking for reduced sodium and low sodium tomato juice could increase following repeated exposure over an extended period. Eighty-three adult subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. Subjects gave liking ratings of four tomato juice samples ranging in sodium from 640 mg (a concentration comparable to a commercially available product) to 136 mg per 237 ml serving (a low sodium concentration) at both taste tests. For the longitudinal study, subjects were divided into two balanced groups based on PROP sensitivity, hedonic sensitivity to salt, and motivation to reduce dietary salt intake; the abrupt group received tomato juice reduced in sodium to reach a low sodium target at week four, and the gradual group received juice reduced in sodium via difference thresholds to reach the same target at week 14. Though liking for the juice with the highest salt content was unchanged between taste tests, liking for all reduced salt juices increased at the final taste test relative to the initial taste test among subjects in both salt reduction groups. In addition, subjects in both groups experienced a downward shift in preference for salt in tomato juice, indicating that repeated exposure may be sufficient to alter preference for salt in a food in the absence of a low sodium diet. That salt preference may be altered by exposure alone within the context of a high salt diet is promising for both the food industry and individual consumers.     

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 relative influence of packaging,labelling, branding and sensory attributes on liking and purchase intent: Consumers differ in their responsiveness

The relative impact of several extrinsic attributes on informed hedonic liking and purchase intent for wine is measured by combining a blind hedonic test with an informed tasting of the same wine packaged in different product concepts. This study separated the relative effect of various attributes and also considers differences between consumers in their responsiveness to various product cues.Five-hundred and twenty-one regular wine consumers participated in a central location test in three German cities in 2005. Respondents first rated hedonic liking of a white wine in a blind condition, then evaluated elements of product concepts differing in four extrinsic attributes, region of origin, grape variety, brand and packaging style, before indicating their liking and purchase intent in an informed condition.Overall, label style and brand evaluation were the strongest drivers for informed liking followed by liking in the blind condition. Purchase intent was influenced directly only by informed liking and price evaluation; the effect of the extrinsic and intrinsic cues is mediated through informed liking. A latent class regression resulted in three consumer segments that differ in the responsiveness of their informed liking to the different product characteristics. Younger inexperienced consumers utilised a mix of various cues, wine experienced consumers based their evaluation mainly on grape variety and blind hedonic liking, and older frequent wine consumers were influenced most strongly by brand and packaging. These findings provide insights into the relative impact of product packaging, branding and labelling on overall product liking and indicate strong differences in how consumers respond to different product characteristics.     

The effect of frequency of consumption of artificial sweeteners on sweetness liking by women

ABSTRACT:  Research into sweetness perception and preference thus far has demonstrated that sweetness preference is related not to the total sugar consumed by an individual but the amount of refined sugar ingested. Research has yet to be conducted, however, to determine whether a diet high in artificial sweeteners contributes to sweetness liking and preference with the same result as a diet high in sugar. The purpose of this research was to determine if such a relationship exists with regard to diets high in artificially sweetened beverages. Seventy-one female participants were recruited and screened for sweetener consumption in beverages. Sixty-four of these individuals were selected for sensory testing. All participants evaluated orange juice samples (ranging from 0% added sucrose to 20% added sucrose) for liking of sweetness using a 9-point hedonic scale. Based on screening survey data, participants were categorized according to sweetener consumption group (artificial sweetener consumers and natural sweetener consumers) and by overall sweetened beverage intake (low or high, regardless of sweetener type normally consumed). Sensory data were analyzed to compare sweetness liking in each of these groups. Significant differences in liking were observed, with individuals in the high sweetened beverage intake group preferring sweeter orange juice than those in the low-intake group. Categorization by sweetener type resulted in no significant differences between the groups, indicating that regardless of the type of sweetener consumed in a beverage, liking of sweetness will be influenced in the same manner.     

Repeatability in hedonic sensory measurement: a conceptual exploration

The traditional view of measurement repeatability is discussed in the light of psychological theories about stability and change in preference and choice behavior. The argumentation is illustrated by data obtained in groups of children and adults who are exposed to the same hedonic sensory measurements a number of times. It is demonstrated that first hedonic impressions are poor predictors of final liking and choice. The repeatability of hedonic methods should be judged on the basis of the stability of the change in preference of different, but comparable populations, rather than on the reliability of repeated measurement in the same population.     

Hedonic tests in different locations as predictors of apple juice consumption at home in elderly and young subjects

The objective of this study was to evaluate the predictive value of hedonic tests on apple juice carried out in a sensory laboratory, University common room and at home (post-consumption test) on ad libitum home consumption measured over 5 consecutive days. Thirty-five elderly volunteers (59–88 years old) and 33 young subjects (20–30 years old) assessed the degree of liking five apple juices varying in sweetness (0, 2, 4, 7 and 10% w/w sucrose added) on a nine-point hedonic scale. Both age groups judged similarly the juice with the lowest sugar concentrations, whereas the juice with 2% sugar added received lower scores from the elderly compared to the young participants. Those samples with higher sweetness (4, 7 and 10%) received higher scores from the elderly compared to the young people. The sample with no sugar added had higher mean score (all the subjects) in the home test (6.92±1.78) compared to both laboratory (5.51±2.15) and common room (5.92±2.08). No such differences were observed for the juices with the other sugar contents. In the elderly group, 1-day intake of apple juice remained on a similar level, regardless of sweetness liking, while among young adults the intake varied, and was highest for juices that were liked most (with 0 and 2% sucrose added). The results showed that hedonic ratings have a limited value as predictors of fruit juice consumption at home. The correlation between rated degree of liking and intake was low, especially for the elderly (r=0.39), indicating that factors other than pleasantness may affect intake. Among three test conditions, the lowest correlation of juice intake was obtained with laboratory test results (r=0.38), relatively higher—when hedonic tests were conducted in common room setting (r=0.49), or as the post-consumption test at home (r=0.73). Further research is required on sensory procedures relevant for the elderly, which together with some other nonsensory factors, would give a better prediction of consumption.     

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!