Differences in perception of sweet and savoury waffles between elderly and young subjects

A review of assessment methods for measuring individual differences in oral somatosensory perception

While taste and smell perception have been thoroughly investigated, our understanding of oral somatosensory perception remains limited. Further, assessing and measuring individual differences in oral somatosensory perception pose notable challenges. This review aimed to evaluate the existing methods to assess oral somatosensory perception by examining and comparing the strengths and limitations of each method. The review highlighted the lack of standardized assessment methods and the various procedures within each method. Tactile sensitivity can be assessed using several methods, but each method measures different tactile dimensions. Further investigations are needed to confirm its correlation with texture sensitivity. In addition, measuring a single textural attribute may not provide an overall representation of texture sensitivity. Thermal sensitivity can be evaluated using thermal-change detection or temperature discrimination tests. The chemesthetic sensitivity tests involve either localized or whole-mouth stimulation tests. The choice of an appropriate method for assessing oral somatosensory sensitivity depends on several factors, including the specific research objectives and the target population. Each method has its unique intended purpose, strengths, and limitations, so no universally superior approach exists. To overcome some of the limitations associated with certain methods, the review offers alternative or complementary approaches that could be considered. Researchers can enhance the comprehensive assessment of oral somatosensory sensitivity by carefully selecting and potentially combining methods. In addition, a standardized protocol remains necessary for each method.

Relationship between texture perception and oral function: A preliminary study in young, healthy adults

BACKGROUND

Oral frailty, characterised by reduced oral function, is associated with systemic health issues in older adults. Although the criteria for diminished oral function often focus on motor and secretory abilities, texture perception also plays a crucial role in health due to its impact on food intake and palatability.

OBJECTIVE

This study aimed to explore the relationship between thickness discrimination ability (TDA) and oral motor and secretory functions in healthy young individuals.

METHODS

Twenty-eight adults were assessed for texture perception using eight concentrations of aqueous xanthan gum solutions to determine TDA scores. Measurements of occlusal force, masticatory performance, tongue pressure, stimulated salivary flow rate and tongue-lip motor function were conducted. Spearman's correlation analysis was used to evaluate the relationship between TDA scores and oral functions. Participants were divided into high-sensitivity and low-sensitivity groups based on their TDA scores to compare oral function test results.

RESULTS

The TDA scores varied among the participants, with higher scores correlating with higher masticatory performance (r = 0.41, p < .05). Masticatory performance in the high-sensitivity group was significantly higher than in the low-sensitivity group (211.9 ± 59.2 mg/dL vs. 157.9 ± 43.0 mg/dL, p = .013), with no significant differences in other oral functions.

CONCLUSION

Masticatory performance was correlated with TDA, suggesting a link between the selection function of mastication and thickness discrimination. These findings highlight the potential relevance of texture perception in oral function and indicate the need for further exploration, particularly in older adults with declining oral health.

Methodological approaches to assess tactile sensitivity in the food context-A scoping review

In contrast to taste sensitivity, the assessment of texture or tactile sensitivity has received relatively little attention in the food context. Texture plays an important role in food preferences and food intake, and individual differences make it important to understand physiological drivers of perception as tactile sensitivity. The multi-dimensional and dynamic aspects of texture perception suggest there is not one single method that can explain individual differences. This scoping review aims to systematically map methods assessing tactile sensitivity, in the context of food, highlighting differences in approach and implementation. Eligibility criteria included papers describing methods to assess individual differences in tactile sensitivity, that involved human participants and the context was relevant to food behavior. Sources are peer-reviewed publications of original research in English. In mapping the methods, we assessed how they relate to food texture parameters (mechanical, geometrical, and surface) and the dynamics of breaking down (touch with hand, first bite/sip, oral processing, residual or after-swallowing sensations). We also review other parameters associated (oral processing, preference, diet and food intake behavior). The literature in this relatively young area is still very fragmented and it is difficult to have a clear picture regarding best practices or recommendations for the measurement of tactile sensitivity in the food context. Future studies should aim to methodological harmonization for application in the food behavior area, with a design of experiment combining different aspects of tactile sensitivity to food, focusing on the thresholds and perceived intensity of textural parameters as well as affective and behavioral responses, and covering the whole spectrum of tactile texture perception (mechanical, geometrics, and surface), including the dynamics of perception.

Chronic intermittent hypoxia impacts the olfactory nervous system in an age-dependent manner: pilot study

PURPOSE

Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse during sleep, which induces chronic intermittent hypoxia (CIH). CIH results in low-grade inflammation, sympathetic overactivity, and oxidative stress. Nevertheless, it remains unclear how exposure to CIH affects olfaction. The purpose of this study was, therefore, to investigate the cytotoxic effects of CIH exposure on mouse olfactory epithelium and the underlying pathophysiology involved.

METHODS

Mice were randomly divided into four groups: Youth mouse (You) + room air (RA), You + intermittent hypoxia (IH), Elderly mouse (Eld) + RA, and Eld + IH (n = 6 mice/group). Mice in the two hypoxia groups were exposed to CIH. The control condition involved exposure to room air (RA) for 4 weeks. Olfactory neuroepithelium was harvested for histologic examination, gene ontology analysis, quantitative real-time polymerase chain reaction (qRT-PCR), and western blotting.

RESULTS

Based on qRT-PCR analysis, olfactory marker protein (OMP), Olfr1507, ADCY3, and GNAL mRNA levels were lower, whereas NGFR, CNPase, NGFRAP1, NeuN, and MAP-2 mRNA levels were higher in the You + IH group than in the You + RA group. Olfactory receptor-regulated genes, neurogenesis-related genes and immunohistochemical results were altered in nasal neuroepithelium under CIH exposure.

CONCLUSIONS

Based on genetic and cytologic analysis, CIH impacted the olfactory neuroepithelium in an age-dependent manner. Our findings suggest that CIH-induced damage to the olfactory neuroepithelium may induce more severe change in the youth than in the elderly.

The processing characteristics of bodily expressions under the odor context: An ERP study

The recognition of facial expressions has been shown to be influenced by contextual odors. The aims of this study were (1) to investigate whether odor has a similar effect on the recognition of bodily expressions, and (2) to analyze the time-course of such effects. Sixty-nine adults were randomized into three groups to identify bodily expressions (happy, fearful, and neutral) in three odor environments (pleasant odor, unpleasant odor, and no odor). Event-related potentials (ERPs) induced by the viewing bodily expressions were analyzed. Behaviorally, the unpleasant odor context promoted the recognition of bodily expressions. The ERP results showed odor influences on bodily expression recognition in two phases. In a middle stage phase (150-200 ms post-stimulus onset), VPP amplitudes induced by bodily expressions were greater in an unpleasant odor context than in a pleasant odor context. In a mid-late stage phase (beyond 200 ms), an interaction between contextual odor and bodily expression type was observed. When exposed to an unpleasant contextual odor, N2 and LPP amplitudes related to fearful bodily expressions were smaller than when exposed to other odor contexts, showing the promoting effect of mood coherence effect. Behavioral and ERP evidence confirmed that contextual odor can modulate the visual processing of bodily expressions, with an overall promoting effect of an unpleasant odor on bodily expression processing (phase one) and a specific modulating influence of odors on affectively congruent/incongruent bodily expressions (phase two).

Influence of Age and Individual Differences on Mouthfeel Perception of Whey Protein-Fortified Products: A Review

Protein needs are considered to increase with age, with protein consumption being associated with many positive outcomes. Protein-fortified products are often used to improve nutritional status and prevent age-related muscle mass loss in older adults. Accordingly, older adults are commonly provided with products fortified with whey protein; however, such products can cause mouthdrying, limiting consumption and product enjoyment. Currently, the extent to which age and individual differences (e.g., saliva, oral health, food oral processing) influence the perception of whey protein-derived mouthdrying is relatively unclear. Previous research in this area has mainly focused on investigating mouthdrying, without taking into account individual differences that could influence this perception within the target population. Therefore, the main focus of this review is to provide an overview of the relevant individual differences likely to influence mouthfeel perception (specifically mouthdrying) from whey protein-fortified products, thereby enabling the future design of such products to incorporate better the needs of older adults and improve their nutritional status. This review concludes that age and individual differences are likely to influence mouthdrying sensations from whey protein-fortified products. Future research should focus more on the target population and individual differences to maximise the benefits from whey protein fortification.

Using Cross-Cultural Consumer Liking Data to Explore Acceptability of PGI Bread-Waterford Blaa

Waterford Blaa is one of only four Irish food products granted protected geographical (PGI) status by the European Commission. This study aimed to determine whether cultural background/product familiarity, gender, and/or age impacted consumer liking of three Waterford Blaa products and explored product acceptability between product-familiar and product-unfamiliar consumer cohorts in Ireland and the UK, respectively. Familiarity with Blaa impacted consumer liking, particularly with respect to characteristic flour dusting, which is a unique property of Waterford Blaa. UK consumers felt that all Blaas had too much flour. Blaa A had the heaviest amount of flouring and was the least preferred for UK consumers, who liked it significantly less than Irish consumers (p < 0.05). Flavour was also important for UK consumers. Blaa C delivered a stronger oven baked odour/flavour compared to Blaa A and was the most preferred by UK consumers. Irish consumer liking was more influenced by the harder texture of Blaa B, which was their least preferred product. Age and gender did not impact liking for Blaas within Irish consumers, but gender differences were observed among UK consumers, males liking the appearance significantly more than females. This is the first paper comparing Waterford Blaa liking of naïve UK consumers with Irish consumers familiar with the product.

Initiation of the age-related decline of odor identification in humans: A meta-analysis

BACKGROUND

Aging is an important contributor to olfactory system deterioration in humans, leading to increased health and safety risks as well as affecting the quality of life. However, it is currently unknown when age-related olfactory deterioration begins in humans and thus when to initiate interventions to prevent or slow it.

OBJECTIVE

To determine the decade in which olfactory function begins to deteriorate in healthy humans by determining when odor identification is first impaired.

DATA SOURCE AND STUDY SELECTION

Studies cited in the PubMed database were searched from its inception to March 2017 using the terms "olfac*" or "smell" and "ag*". The effect size of each comparison was calculated.

RESULTS

In this meta-analysis, the effect sizes as determined using Cohen's d for the comparisons between 30 and 39.9- and 40-49.9-year-olds was 0.06 (95% CI: -0.17 to 0.29), between 40-49.9-year-olds was 0.62 (95% CI: 0.20-1.04), considered a medium effect size, and between 35-55-year-olds and those >55years old was 1.12 (95% CI: 1.06-1.45), considered a very large effect.

CONCLUSION

Olfactory function deterioration, as determined by an impaired ability to identify odors, starts in the fifth decade of life in healthy humans.

Understanding the sensory characteristics and drivers of liking for gochujang (Korean fermented chili pepper paste)

The present study investigated the sensory characteristics of 31 types of gochujang, a Korean fermented chili paste, produced in various regions of Korea. Generic descriptive analysis was conducted to analyze the sensory properties of the samples. Among these, four samples were selected for consumer taste test based on their distinct sensory profiles. The drivers of liking for gochujang were identified when the samples were applied to four different food systems. Consumers (age range: 20's-60's) rated the acceptance of the samples. ANOVA and multivariate analyses were conducted on the data. The types of carbohydrate sources or usage of additional seasoning showed stronger influence on the sensory characteristics of gochujang than the production location. Samples with strong fermented soy and fish sauce characteristics were fairly unacceptable to the consumers. The positive drivers of gochujang were appropriate levels of spiciness and sweet odors/flavors, whereas the negative drivers were off-note and fermentation-related flavors.

A Role for Identification in the Gradual Decline in the Pleasantness of Flavors With Age

OBJECTIVES

This study investigated a possible role for identification in the decline in flavor pleasantness with age.

METHODS

Two hundred sixty-four individuals aged from 16 to 85 years tasted 6 flavored drinks of varying identity and ease of identification, and rated each on pleasantness, a range of other characteristics and identified all flavors.

RESULTS

Using regression, firstly, pleasantness was inversely associated with age (β = -0.22, p < .01). Secondly, the decline in pleasantness with age was associated with poorer identification (β = 0.30, p < .01), lower perceptions of sweetness (β = 0.01, p < .01), lower strength of flavor (β = 0.00, p = .02), lower familiarity (β = 0.01, p < .01), and a lower frequency of usual drink consumption (β = 0.04, p < .01). Thirdly, improved identification with age was associated with increased drink familiarity (β =< 0.01, p < .01), coloration compared with no color (β = <0.06, p < .01), and correct compared with incorrect coloration (β = <0.27, p < .01).

DISCUSSION

These findings demonstrate a clear role for identification in the decline in flavor pleasantness with age. These findings thus provide clear evidence for a cognitive and perceptual element to these hedonic processes. Our findings suggest that likings for flavors in older individuals may be increased/maintained through the use of improved visual cues, easily recognizable foods, and/or identity labels.

Odor-Specific Loss of Smell Sensitivity with Age as Revealed by the Specific Sensitivity Test

The perception of odor mixtures plays an important role in human food intake, behavior, and emotions. Decline of smell acuity with normal aging could impact food perception and preferences at various ages. However, since the landmark Smell Survey by National Geographic, little has been elucidated on differences in the onset and extent of loss in olfactory sensitivity toward single odorants. Here, using the Specific Sensitivity test, we show the onset and extent of loss in both identification and detection thresholds of odorants with age are odorant-specific. Subjects of Chinese descent in Singapore (186 women, 95 men), aged 21-80 years, were assessed for olfactory sensitivity of 10 odorants from various odor groups. Notably, subjects in their 70s required 179 times concentration of rose-like odorant (2-phenylethanol) than subjects in the 20s, while thresholds for onion-like 2-methyloxolane-3-thiol only differed by 3 times between the age groups. In addition, identification rate for 2-phenylethanol was negatively correlated with age throughout adult life whereas mushroom-like oct-1-en-3-ol was equally identified by subjects across all ages. Our results demonstrated the girth of differentiated olfactory loss due to normal ageing, which potentially affect overall perception and preferences of odor mixtures with age.

Investigating age-related changes in taste and affects on sensory perceptions of oral nutritional supplements

BACKGROUND

sip feeds are oral nutritional supplements (ONSs) that are commonly prescribed to malnourished patients to improve their nutritional and clinical status. However, ONSs are poorly consumed and frequently wasted, with sweetness being identified as one of the factors leading to patients' dislike of ONSs.

OBJECTIVES

to investigate if age affects sweetness thresholds and if this impacts upon perceived sweetness intensity, hedonic (sweetness and overall) and ranked preference of ONS products.

DESIGN

prospective, observational.

SUBJECTS

thirty-six young adults (18-33 years) and 48 healthy older adults (63-85 years).

SETTING

Department of Food and Nutritional Sciences and the Clinical Health Sciences at the University of Reading.

METHODS

detection and recognition threshold levels, basic taste identification and 'just about right' level of sweetness were examined. Three ONSs (chocolate, vanilla, strawberry) and sucrose solutions were evaluated for hedonic sweetness, overall hedonic liking, sweetness intensity and rank preference.

RESULTS

significant differences were found in both sweetness detection and recognition thresholds (P = 0.0001) between young and older adults, with older adults more likely to incorrectly identify the taste (P = 0.0001). Despite the deterioration in sweetness sensitivity among the older adults, there were no significant differences found in sweetness intensity perceived for the ONS products presented (P > 0.05) when compared with the young adults. However, across both groups sweetness intensity was found to be correlated with overall product dislike across all flavour variants tested (R = 0.398, P = 0.0001).

CONCLUSIONS

sweetness appears to be one of many factors contributing to the dislike of ONSs. Manufacturers are encouraged to reconsider the formulations of these products so that beneficial effects of ONSs can be delivered in a more palatable and acceptable form and wastage reduced.