ABSTRACT
The chewing process transforms food into bolus for a safe swallow. It is known that humans adapt their chewing behavior to food product characteristics. This study aimed at identifying ...individual chewing strategies of healthy consumers and determining the respective consequences on bolus properties. For that purpose, the chewing activity of 50 subjects was recorded during consumption of five model cheeses. Boluses were collected at the swallowing threshold for rheological analyses. We found that 30% of subjects showed only slight adaptation of chewing activity to product characteristics and thus produced boluses with different rheological properties. Among the 70% of subjects who adapted their chewing behavior, 57% adapted their behavior via chewing time and 40% adapted their behavior via chewing time and muscular contraction amplitude. Among the bolus rheological parameters, only consistency was not influenced by chewing strategies. Hence, it seemed to be a determinant factor of the swallowing threshold for these products.
PRACTICAL APPLICATIONS
Flavor compounds are released during the oral processing of food. It is thus important to understand how consumers form a bolus and to analyze the consequences of chewing behaviors on bolus properties at the swallowing threshold, at the end of the oral stage of food, to clarify the role of mastication in the release of stimuli responsible for perception. Chewing strategies and bolus properties are some of the key factors of flavor release and product acceptability that is of interest for food manufacturers who can use these factors as additional parameters for new solid product design.
The aim of this study was to examine the influence of the texture of dairy products on bolus properties and food comfortability as perceived by elderly persons.
Four cheese models identical in terms ...of their nutritional composition but different by the type of texture (Soft, Hard, Processed and Whipped) were developed to resemble market cheese. Study was performed with a panel of 38 elderly persons without dental impairment but with variable rate of saliva flow. The time of chewing required to form the bolus was measured. The rheological properties of the bolus obtained were studied as well as the quantity of saliva incorporated. Food comfortability was assessed by means of a questionnaire asking about in-mouth comfort, bolus formation, pain, and perceived texture and flavor.
Results showed that food comfortability was positively correlated to the ease of forming the bolus which depended on the food texture. Thus, the bolus formed with the Whipped product which required more saliva, was harder than the other three products and so judged the least comfortable. This product was characterized by a dry and sticky texture. On the other hand, the Soft and Processed products led to a softer food bolus that was more easily formed, and thus were judged as more comfortable. Their textures were perceived as soft, fatty and melting.
This work highlights the importance of considering food bolus formation and related properties when looking for the link between food product characteristics and the enjoyment of eating in the case of the elderly population.
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•Bolus of hard and dry model cheeses were difficult to form.•Melting and fatty model cheeses bolus were easy to form.•The bolus characteristics and the perception of bolus formation were correlated.•Elderly found model cheeses more comfortable when the bolus was easily formed.
For human beings, the mouth is the first organ to perceive food and the different signalling events associated to food breakdown. These events are very complex and as such, their description ...necessitates combining different data sets. This study proposed an integrated approach to understand the relative contribution of main food oral processing events involved in aroma release during cheese consumption. In vivo aroma release was monitored on forty eight subjects who were asked to eat four different model cheeses varying in fat content and firmness and flavoured with ethyl propanoate and nonan-2-one. A multiblock partial least square regression was performed to explain aroma release from the different physiological data sets (masticatory behaviour, bolus rheology, saliva composition and flux, mouth coating and bolus moistening). This statistical approach was relevant to point out that aroma release was mostly explained by masticatory behaviour whatever the cheese and the aroma, with a specific influence of mean amplitude on aroma release after swallowing. Aroma release from the firmer cheeses was explained mainly by bolus rheology. The persistence of hydrophobic compounds in the breath was mainly explained by bolus spreadability, in close relation with bolus moistening. Resting saliva poorly contributed to the analysis whereas the composition of stimulated saliva was negatively correlated with aroma release and mostly for soft cheeses, when significant.
Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the ...chocolates' headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi² test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.
Proton Transfer Reaction-Time-of-Flight- Mass Spectrometry (PTR-ToF-MS) is an analytical chemistry technique that can be used for measuring the concentration of volatile organic compounds directly in ...the subjects’ noses (nosespace, in vivo analysis) during a tasting and over time. It can be combined with temporal sensory methods such as Temporal Dominance of Sensations (TDS) or Temporal Check All That Apply (TCATA) in order to obtain simultaneous sensory and physico-chemical signals. This paper aims to provide a methodology to analyze in vivo PTR-MS and temporal sensory data and illustrate it on a real dataset. First, relevant pretreatments of PTR-MS data were established, including breathing correction, blank periods removal and standardization. Then, a statistical multiblock analysis was presented: the Regularized Generalized Canonical Correlation Analysis (RGCCA). The versality of the approach was demonstrated, as it can be used to answer most of problematics (exploratory or supervised). Finally, this methodology is illustrated on a dataset of PTR-MS and TDS or TCATA data collected simultaneously. In this study, 16 semi-trained subjects evaluated 3 chocolates in TDS and TCATA on six flavor attributes (Spicy, Cocoa, Woody, Fruity, Roasty and Dry Fruits) with 2 replicates for each sensory method. Results showed that TCATA and TDS gave similar results, but TDS was shown to slightly better preserve the PTR-MS observed product configuration than TCATA. All computing tools developed in this work are freely available.
Objectives
This systematic literature review aims to summarize the existing scientific evidence about the association between a reduced salivary function and food consumption in elderly people.
...Methods
A validated search strategy in two databases (PubMed and ISI Web of Knowledge) was carried out and retrieved papers together with their reference lists were screened by two independent reviewers. The quality of the included studies was critically appraised via the Quality Assessment Criteria for Evaluating Primary Research Papers.
Results
From the originally identified studies (n=391), only 15 articles (all cross-sectional studies) met the pre-fixed inclusion/exclusion criteria. The methodological quality of the included studies was in general good, although only 3 from 15 obtained the maximum score. The control of confounding factors was the quality variable more poorly rated in the selected studies. Salivary hypofunction was associated with a decrease of the objective chewing and swallowing abilities and taste perception. Moreover, most of the selected studies showed a relationship between salivary hypofunction and food consumption (in terms of appetite loss, unbalanced dietary intake and malnutrition), although no causality could be established.
Conclusions
This study highlights the fact that salivary hypofunction definition and measurements are different across the studies. Therefore, future research efforts should focus on establishing a gold standard to define and identify salivary hypofunction throughout life and on performing longitudinal studies controlling for confounding factors to establish causality..
Pet food production is a fast-growing industry. While extruded dry pet food is the favored pet food due to its convenience of use, it may have poorer palatability than other pet foods such as wet pet ...foods. However, palatability plays a pivotal role in meeting nutritional requirements or providing therapeutic benefits in cats and dogs, as it ensures food acceptance. Thus, both academics and manufacturers conduct routine palatability tests to assess acceptance and preference of products among pets, alongside sensory analyses involving human panels. Palatability is greatly influenced by species-specific and environmental factors in cats and dogs. The review will hence present the current knowledge on palatability assessment and animal food perception; it will then aim to explore strategies for effectively managing palatability in dry pet food by examining the impact of key ingredients and process parameters on the finished product's palatability. Moreover, the demands and needs for sustainable and healthier products as well as supply constraints present novel challenges and opportunities for academics and manufacturers.
The aim of our study was to explain inter-individual differences on in vivo aroma release during cheese consumption by oral physiological parameters.
To reach this objective, 34 subjects were ...recruited. Their salivary flow, oral volume and velum opening were determined. Six cheddar-based melted cheeses with different fat levels and firmness were flavoured with nonan-2-one (NO) and ethyl propanoate (EP). During their consumption (free protocol), in vivo retro nasal aroma release was followed by Atmospheric Pressure Chemical Ionisation–Mass Spectrometry (APCI–MS). Chewing activity was evaluated by electromyography recordings. Bolus saliva content, mouth-coating, and bolus rheology were also determined.
Based on the quantity of aroma released before and after swallowing, subjects can be clustered into three groups: the first one (HRG) is characterized by a large quantity of aroma release whatever the aroma compound; the second one (MRG) showed a large release for EP and a lower one for NO; the third group (LRG) was characterized by a low quantity of aroma release whatever the compound.
Whatever the group of subjects, fat and firmness effects differed according to the aroma compound. EP release increased with firmness and fat content, whereas NO release was not affected by firmness and decreased when fat content increased. Physiological parameters which better differentiated the three groups of subjects according to their release behaviour were chewing activity, mouth coating and frequency of velum opening.
Subjects from HRG were differentiated from LRG subjects by a higher chewing activity, and more frequent velum opening. Subjects from MRG presented a lower mouth coating explaining their lower release of NO, the more hydrophobic compound.
This study shows that the total amount of aroma released in the nasal cavity during food consumption depends not only on the characteristics of the product but also on the oral physiology of the subjects and on their food oral processing.
•Inter-individual differences in aroma release are explained by human oral physiology.•Low release subjects: velum opening at deglutition events, weak chewing parameters.•High release subjects: frequent velum opening and large chewing parameters.•Different release behaviours were observed in function of aroma hydrophobicity.
Fat perception during eating is a complex sensation that involves various sensory modalities, such as texture, aroma and taste. Taste is supported by the discovery of fatty acid receptors in the ...tongue papillae. Dietary fat is mainly composed of esterified fatty acids, whereas only free fatty acids can bind to taste receptors. Some authors have mentioned the necessity and efficiency of salivary lipolytic activity to hydrolyse the esterified fatty acids present in foods and enable fat perception. Our hypothesis is that salivary lipolytic activity is also involved in regulating the basal level of salivary fatty acids in humans. To test this hypothesis, total fatty acid (TFA) and free fatty acid (FFA) concentrations and selected salivary characteristics (such as lipolytic activity) were analysed in the resting saliva of 54 subjects. The results show differences in the TFA and FFA profiles, with TFA and FFA concentrations of 8.99 and 3.56 µg/mL of saliva, respectively. Interestingly, lipolytic activity had a significant positive correlation with FFA concentration (0.51, p < 0.01). This result highlights a possible physiological role of salivary lipolytic activity in the regulation of the basal FFA concentration. This regulation could be involved in fat taste sensitivity.
•A definition of oral comfort when eating a food in the elderlies is proposed.•Understanding oral comfort allowed the development of a questionnaire.•Assessing oral comfort in cereal and meat ...products enabled a product discrimination.•This concept should be taken into account when designing food for elderly.
In the elderly population, ageing frequently impacts on the different aspects of oral physiology that play a key role in eating behavior. In the context of an aging population, it is crucial to develop a food supply tailored for the elderly people in order to prevent the onset of malnutrition. To meet this challenge, we looked for the concept of “oral comfort” when eating a food. The present study aimed at i) exploring the concept of oral comfort when eating according to elderly people in order to develop a questionnaire to evaluate the oral comfort when eating a food and ii) asking elderly people to evaluate various meat and cereal products using this questionnaire. Results of focus groups highlighted that oral comfort when eating a food is a multi-dimensional concept which includes dimensions related to food oral processing (ability to form and swallow food bolus), food sensory properties (texture and taste) and to a lesser extent pain sensations. Furthermore, the oral comfort questionnaire developed in the present study enabled a discrimination of products and highlighted the fact that some products supposed to fit with elderly people capacities and needs were not rated as the most comfortable foods by the elderly people. The concept of oral comfort when eating a food should be taken into account by those who are willing to design food products tailored to the elderly population. The questionnaire could be an interesting tool to assess oral comfort when eating a food in the elderly population.
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