The nutritional impact of metallic taste in head and neck cancer patients: explorations and clinical implications.

PURPOSE: Metallic taste (MT) is frequently observed during head and neck cancer treatments, but very little is known about its impact on nutritional status. The aim of this study was to explore the impact of MT on the quality of life and nutritional status in patients with head and neck cancer expressing MT. METHODS: Questionnaires on quality of life, MT, weight, and food intake were filled out by 44 patients with head and neck cancer before, during, and up to 1 year after their treatment. Patients were divided into two groups based on their reported experience of MT. RESULTS: MT was commonly observed (n = 12, 27.2%), always during the treatment phase, and mostly linked with radiotherapy or radiochemotherapy. Reported MT intensity was moderate (n = 6, 40%) to high (n = 4, 26.7%). MT had a significant negative impact on quality of life linked to dysgeusia (p = 0.025). The negative impacts of MT on food intake and on weight were not significant, possibly due to a combination of sample size, dropouts, and duration of observation. Further research in this area could provide additional insights into how to better address the issue related to MT and enhance the quality of care provided to this patient population. CONCLUSION: Metallic taste, experienced by 27.2% of the 44 patients with head and neck cancer, contributes to dysgeusia and results in a significant decline in quality of life associated with dysgeusia. TRIAL REGISTRATION: ClinicalTrials.gov trial registration number: NCT03558789.

Influence of Cheese Composition on Aroma Content, Release, and Perception.

The quality of a cheese is determined by the balance of aroma compounds primarily produced by microorganisms during the transformation of milk into ripened cheese. The microorganisms, along with the technological parameters used in cheese production, influence aroma formation. The perception of these compounds is further influenced by the composition and structure of the cheese. This study aimed to characterize how cheese composition affects aroma compound production, release, and perception. Sixteen cheeses were produced under controlled conditions, followed by a quantitative descriptive analysis post ripening. Aroma composition was analyzed using HS-SPME-GC-MS, and a dynamic sensory evaluation (TCATA) was combined with nosespace analysis using PTR-ToF-MS. Image analysis was also conducted to characterize cheese structure. Cheese fat and whey lactose contents were identified as key factors in the variability of sensory attributes. GC-MS analyses identified 27 compounds correlated with sensory attributes. In terms of aroma compound release, 23 ions were monitored, with fat, salt, and lactose levels significantly affecting the release of most compounds. Therefore, cheese fat, salt, and whey lactose levels, as well as the types of microbial strains, play a role in influencing the composition, structure, release of aroma compounds, and sensory perception.

Astringency Sensitivity to Tannic Acid: Effect of Ageing and Saliva.

Astringency is an important sensory characteristic of food and beverages containing polyphenols. However, astringency perception in elderly people has not been previously documented. The aim of the present work was to evaluate sensitivity to astringency as a function of age, salivary flow and protein amount. Fifty-four panellists, including 30 elderly people (age = 75 ± 4.2 years) and 24 young people (age = 29.4 ± 3.8 years), participated in this study. Astringency sensitivity was evaluated by the 2-alternative forced choice (2-AFC) procedure using tannic acid solutions. Whole saliva was collected for 5 min before and after the sensory tests. The results showed that the astringency threshold was significantly higher in the elderly group than the young group. No correlation was observed between the salivary protein amount and threshold value. However, a negative correlation between salivary flow and threshold was observed in the young group only. These results showed a difference in oral astringency perception as a function of age. This difference can be linked to salivary properties that differ as a function of age.

Salt and Aroma Compound Distributions Influence Flavour Release and Temporal Perception While Eating Hot-Served Flans.

To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight-Mass Spectrometry) to assess the release of aroma compounds in vivo, and ATI (Alternate Time-Intensity) and TDS Temporal Dominance of Sensations) to evaluate perception as a function of time. The obtained results confirmed that the strategy of concentrating salt in the outer layer of a multilayer product was the optimal solution with respect to taste intensity. Heterogeneous salt distribution decreased aroma compound release and consequently aroma intensity but in different ways according to both salt and added aroma distribution in the food matrix. The salty taste enhancement could be due to the initial strong dominance of the salty sensation at the very beginning of the eating process. The involved mechanisms rely on a combination of physico-chemical and perceptual effects which are not clear yet.

Astringency sensitivity to tannic acid: Effect of ageing and salivary proline-rich protein levels.

The link between salivary composition and sensitivity to astringency as a function of age has still not been established. In this work, we propose the hypothesis that ageing leads to changes in the concentration of salivary proline-rich proteins (PRPs), which alters the astringency perception threshold with age. To test this hypothesis, astringency sensitivity to tannic acid and saliva was assessed in 30 elderly people and 24 young people. Basic PRPs (bPRPs) and glycosylated PRPs (gPRPs) were quantified immunochemically via western blot analysis. The results showed that the amounts of bPRPs and gPRPs were similar between the young and elderly groups. However, a positive correlation between the gPRP amount and astringency threshold was observed only in the young group, while a negative correlation between the bPRP amount and astringency threshold was observed only in the elderly group. This finding suggests differences in the contribution of PRP type to astringency perception as a function of age.

A domestic-like carrot cooking methodology for multiple research applications.

Domestic-oriented research focusing on food requires methodologies that closely mimic practices occurring in home kitchens while meeting scientific standards. Currently however, there is a lack of methodologies that can be implemented in both laboratory and home environments. This paper proposes a method that fulfills the scientific requirements of repeatability and reproducibility, while utilizing commonly available materials and processes found in the average household. The method is applied to the preparation, boiling, and seasoning of roots of Daucus carota L. ("carrots"), which can be employed in various scientific fields with only minor adjustments. Three scientific experiments utilizing this methodology are presented, namely sensory evaluation, ionic chromatography measurements, and NMR experiments. In the existing literature, numerous protocols have been used for carrot sample preparation, hindering direct comparisons between studies. In this paper we would like to highlight the ability of the methodology to enhance comparability, as well as its potential utilization in other research applications. The main principles underlying the proposed methodology can also be extrapolated to prepare samples of several other vegetables or cereals.•Comprehensive guidelines for standardizing the shapes, lengths, and widths of carrots are outlined, ensuring minimal variability while preserving the integrity of the raw material.•The cooking method for carrots is tailored to utilize commonly available household materials, while meeting scientific standards required for research purposes.•Seasoning practices involving readily available domestic materials, like commercial salt, are suggested.

Salivary protein profiles and sensitivity to the bitter taste of caffeine.

The interindividual variation in the sensitivity to bitterness is attributed in part to genetic polymorphism at the taste receptor level, but other factors, such as saliva composition, might be involved. In order to investigate this, 2 groups of subjects (hyposensitive, hypersensitive) were selected from 29 healthy male volunteers based on their detection thresholds for caffeine, and their salivary proteome composition was compared. Abundance of 26 of the 255 spots detected on saliva electrophoretic patterns was significantly different between hypo- and hypersensitive subjects. Saliva of hypersensitive subjects contained higher levels of amylase fragments, immunoglobulins, and serum albumin and/or serum albumin fragments. It also contained lower levels of cystatin SN, an inhibitor of protease. The results suggest that proteolysis occurring within the oral cavity is an important perireceptor factor associated to the sensitivity to the bitter taste of caffeine.

Reducing Sodium Content in Cheeses While Increasing Salty Taste and Fat Perception Using Aroma.

Excess salt (NaCl) and fat intake are major causes of chronic diseases, but reducing such components without affecting acceptability is a major challenge. Here, we set out to examine whether added aroma in lower salt cheese can enhance saltiness and fat perception. Low-salt cheese samples were grated through a homogenizer, and then aroma solution, sardine aroma (salt-associated), butter aroma (fat-associated) and a mix of sardine and butter aromas were added. The results confirmed that grating changes cheese texture, leading to induced taste perception. In addition, a significant saltiness enhancement was induced by sardine aroma and to a lesser extent by butter aroma, while significant fat perception enhancement was only induced by blended aroma. These findings show that aroma addition can be a strategy to compensate for sodium reduction in commercial cheese. Concerning fat perception, the addition of aroma can be a good strategy to compensate for low-fat in commercial cheeses. However, the mechanisms involved seem complex and need to be elucidated.

Perspectives on Astringency Sensation: An Alternative Hypothesis on the Molecular Origin of Astringency.

Flavor is one of the main drivers of food consumption and acceptability. It is associated with pleasure feels during eating. Flavor is a multimodal perception corresponding to the functional integration of information from the chemical senses: olfaction, gustation, and nasal and oral somatosensory inputs. As a result, astringency, as a sensation mediated by the trigeminal nerves, influences food flavor. Despite the importance of astringency in food consumer acceptance, the exact chemosensory mechanism of its detection and the nature of the receptors activated remain unknown. Herein, after reviewing the current hypotheses on the molecular origin of astringency, we proposed a ground-breaking hypothesis on the molecular mechanisms underpinning this sensation as a perspective for future research.

The Associations between Biochemical and Microbiological Variables and Taste Differ in Whole Saliva and in the Film Lining the Tongue.

The objective of this work was to investigate whether the biological film lining the tongue may play a role in taste perception. For that purpose, the tongue film and saliva of 21 healthy subjects were characterized, focusing on microorganisms and their main metabolic substrates and products. In parallel, taste sensitivity was evaluated using a test recently developed by our group, and the links between biological and sensory data were explored by a correlative approach. Saliva and tongue film differed significantly in biochemical composition (proportions of glucose, fructose, sucrose, and lactic, butyric, and acetic acids) and in microbiological profiles: compared to saliva, tongue film was characterized by significantly lower proportions of Bacteroidetes (p<0.001) and its main genus Prevotella (p<0.01) and significantly higher proportions of Firmicutes (p<0.01), Actinobacteria (p<0.001), and the genus Streptococcus (p<0.05). Generic taste sensitivity was linked to biological variables in the two compartments, but variables that appeared influent in saliva (flow, organic acids, proportion of Actinobacteria and Firmicutes) and in tongue film (sugars and proportions of Bacteroidetes) were not the same. This study points to two interesting areas in taste research: the oral microbiome and the specific characterization of the film lining the tongue.

Impact of blade tenderization, marinade and cooking temperature on oral comfort when eating meat in an elderly population.

Several studies demonstrated that oral health impairment, such as tooth loss or a decrease in salivary flow might lead elderly people to reduce their meat intake. The present study assessed the impact of culinary processes liable to improve meat texture and smooth down meat oral processing, in order to fulfil the oral capacities of elderly people. Four culinary processes were selected: cooking bag, blade tenderizer, marinade and low-temperature cooking. A panel of 40 elderly participants with good and poor dental status were asked to assess 5 chicken breast samples, 5 roast beef samples and 4 beefsteak samples prepared according to different process conditions by using an "oral comfort" questionnaire. Results highlighted the fact that oral impairment may alter food bolus formation as well as texture perception while eating meat in elderly people. Furthermore, they revealed that easy-to-do culinary processes may improve meat tenderness and juiciness as well as smooth down food bolus formation, in particular for the roast beef.

Using food comfortability to compare food's sensory characteristics expectations of elderly people with or without oral health problems.

Food consumption is by far the most important point where food's organoleptic properties can be perceived and can elicit sensory pleasure. Ageing is often accompanied by oral impairments. Those impairments may impact food perception by changing texture perception and the release of flavor components, which have a significant impact on food acceptability. The present study aimed at evaluating the impact of oral health on the perception of food comfortability in an elderly population. This was achieved by asking elderly people with a good oral health and elderly people with poor oral health to rate six cereal products and six meat products using a food comfortability questionnaire. Thirty-seven and 35 elderly people (65-87 years old) underwent either a cereal or meat session, respectively. The present study showed very few effects of dental and saliva status on food perception. For the cereal products, a significant effect of dental status was observed for one texture descriptor and one flavor descriptor, and a significant effect of salivary status was observed for two texture descriptors and one flavor descriptor. For the meat products, a significant effect of dental status and a significant effect of salivary status were observed on one flavor descriptor. For both products, no significant impact of dental or salivary status was observed on the general perception of food oral comfort nor on food bolus formation. Future studies exploring the impact of a broader set of oral parameters and potential adapting factors are needed to further explore the results of the present study. PRACTICAL APPLICATIONS: During oral food consumption, mastication, salivation, and swallowing play a key role in the acceptance of food and beverages by modulating the perception of texture, taste, and aroma, as well as providing eating comfort by assisting the food breakdown process into a bolus that can be safely swallowed. The age-related oral impairments such as loss of teeth, decrease in salivary flow or dysphagia are known to have an impact on food consumption. However, very few products are developed to skirt those impairments. Therefore, in the context of an ageing population, there is a need to develop functional foods that meet the specific nutritional needs of the elderly population, as well as a well-balanced flavor and texture framework. Considering the large interindividual variability observed on the elderly people, developing adapted functional foods is a major challenge for the food industry and society.

Chewing bread: impact on alpha-amylase secretion and oral digestion.

During chewing, saliva helps in preparing the food bolus by agglomerating the formed particles, and it initiates enzymatic food breakdown. However, limited information is actually available on the adaptation of saliva composition during the oral processing of complex foods, especially for foods that are sensitive to salivary enzymes. We addressed this question in the context of starch-based products and salivary alpha-amylase. The objectives were two-fold: (1) to determine if salivary alpha-amylase secretion can be modulated by the bread type and (2) to evaluate the contribution of the oral phase in bread enzymatic breakdown. Mouthfuls of three different wheat breads (industrial, artisan and whole-meal breads) were chewed by twelve subjects. Saliva samples were collected at rest and at different times corresponding to 33, 66 and 100% of the individual's chewing sequence. Alpha-amylase activity and total protein content were determined for all saliva samples that were collected. Additionally, the salivary maltose concentration was measured as a marker of bread enzymatic digestion. Boluses were collected at the swallowing time to evaluate the saliva uptake. Chewing industrial bread induced higher saliva uptake than the other breads despite a similar chewing duration. The evolution of salivary amylase activity tended to depend on the type of bread and was highly influenced by a large degree of inter- and intra-subject variability. The protein and maltose concentration steadily increased during chewing as a result of bread breakdown. The salivary protein concentration was mainly affected by the release of the water-soluble proteins of the bread. The salivary maltose concentration was found to be significantly lower for the whole-meal bread. When considering the weight of the mouthful, enzymatic breakdown was found to be most efficient for the breads ranking from industrial > artisan > whole-meal.

Combined heterogeneous distribution of salt and aroma in food enhances salt perception.

Aroma-taste interactions and heterogeneous spatial distribution of tastants were used as strategies for taste enhancement. This study investigated the combination of these two strategies through the effect of heterogeneous salt and aroma distribution on saltiness enhancement and consumer liking for hot snacks. Four-layered cream-based products were designed with the same total amount of sodium and ham aroma but varied in their spatial distribution. Unflavoured products containing the same amount of salt and 35% more salt were used as references. A consumer panel (n = 82) rated the intensity of salty, sweet, sour, bitter and umami tastes as well as ham and cheese aroma intensity for each product. The consumers also rated their liking for the products in a dedicated sensory session. The results showed that adding salt-associated aroma (ham) led to enhancement of salty taste perception regardless of the spatial distribution of salt and aroma. Moreover, products with a higher heterogeneity of salt distribution were perceived as saltier (p < 0.01), whereas heterogeneity of ham aroma distribution had only a marginal effect on both aroma and salty taste perception. Furthermore, heterogeneous products were well liked by consumers compared to the homogeneous products.

The impact of mastication, salivation and food bolus formation on salt release during bread consumption.

Health authorities recommend higher fibre and lower salt content in bread products. However, these basic ingredients of bread composition are multifunctional, and important changes in their content influence the texture, flavour and acceptability of the product. This study was designed to investigate the link between oral processing, bolus formation and sodium release during the consumption of four different breads that varied in composition and structure. Chewing behaviour was determined by surface electromyography, and salivation was quantified from the water content of the boluses collected. The kinetics of bread degradation during food bolus formation was characterised by measuring the bolus heterogeneity by texture image analysis, and sodium release into the saliva was quantified. Mastication and salivation varied between products and between subjects, thus highlighting different bolus formation strategies. In vivo salt release was mainly explained by mastication parameters. The initial slope of sodium release increased when the chewing muscles' activity increased, and the maximum sodium concentration was reached later when more masticatory cycles were required to reach the swallowing point.

The salt and lipid composition of model cheeses modifies in-mouth flavour release and perception related to the free sodium ion content.

Reducing salt and lipid levels in foodstuffs without any effect on acceptability is a major challenge, particularly because of their interactions with other ingredients. This study used a multimodal approach to understand the effects of changes to the composition of model cheeses (20/28, 24/24, 28/20 lipid/protein ratios, 0% and 1% added NaCl) on sodium ion mobility ((23)Na NMR), in-mouth sodium release and flavour perception. An increase in the salt content decreased cheese firmness and perceived hardness, and increased sodium ion mobility, in vivo sodium release and both saltiness and aroma perception. With the same amount of salt, a lower lipid/protein ratio increased the firmness of the cheeses, perceived hardness, and decreased sodium ion mobility, in vivo sodium release, saltiness and aroma perception. These findings suggest on one hand that it could be possible to increase saltiness perception by varying cheese composition, thus inducing differences in sodium ion mobility and in free sodium ion concentration, leading to differences in in-mouth sodium release and saltiness perception, and on the other hand that the reformulation of foods in line with health guidelines needs to take account of both salt content and the lipid/protein ratio.

In vivo sodium release and saltiness perception in solid lipoprotein matrices. 2. Impact of oral parameters.

This study aimed to investigate the relationships between sodium release, saltiness, and oral parameters during the eating of lipoprotein matrices (LPM). Sodium release and saltiness relative to 10 LPM were recorded during normal mastication by five subjects with differing oral parameters (chewing efficiency and salivary flow rate). The LPM samples varied in composition (dry matter, fat, salt, and pH levels) and represented a broad range of hardness. Mastication was recorded using electromyography simultaneously with sensory assessment. Differences in chewing behavior could explain most of the variability in sodium release and saltiness among subjects. Subjects with a higher chewing force and lower salivary flow rate experienced higher levels of sodium release and saltiness. In terms of the LPM, sodium release and saltiness were affected by either chewing behavior or food composition.

In vivo sodium release and saltiness perception in solid lipoprotein matrices. 1. Effect of composition and texture.

Reducing the sodium content in foods is complex because of their multidimensional sensory characteristics and the multifunctionality of sodium chloride. The aim of this study was to elucidate how food composition may influence in-mouth sodium release and saltiness perception. Lipoprotein matrices (LPM) were produced using milk constituents and characterized by means of rheological measurements, texture, and taste sensory profiles. Texture and taste perceptions were affected differently by variations in the salt level, dry matter, and fat contents. Composition and textural changes also modified temporal sodium release and saltiness perception recorded in five subjects, but the effects varied as a function of the salt content. The water content mainly appeared to influence the amount of sodium released, whereas saltiness perception was mainly related to fat content. Elasticity, coating, and granularity were found to be correlated with temporal sodium release and/or saltiness parameters.