The eating capability: Constituents and assessments

Association between Number of Teeth and Eating out of Home: A 2019 Statistical Survey of the Japanese Representative Population

Eating out of home (EOH), with its diverse food options, can benefit those with difficulty preparing their meals, especially older adults. Oral health status may be a determinant of EOH, as food accessibility is influenced by oral health, but this association remains unclear. This cross-sectional study used merged data from two national statistical surveys conducted in 2019. Participants were individuals aged ≥ 65 years who responded to both surveys. The frequency of EOH ( Collapse

Key Words

• eating out
• older population
• oral health

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MESH Headings

• Aged
• Aged, 80 and over
• Female
• Humans
• Male
• Cross-Sectional Studies
• East Asian People
• Feeding Behavior
• Japan/epidemiology
• Meals
• Oral Health/statistics & numerical data
• Prevalence
• Surveys and Questionnaires
• Tooth Loss/epidemiology

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Grants

• 202209053A Ministry of Health, Labour and Welfare
• JPMJSP2114 Japan Science and Technology Agency

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Affiliation(s)

Anna Kinugawa Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan; (A.K.); (T.K.); (K.T.); (K.O.)
Takafumi Yamamoto Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan; (A.K.); (T.K.); (K.T.); (K.O.) Preventive Dentistry, Hokkaido University Hospital, Kita 13 jo Nishi 7 Chome, Kita-ku, Sapporo 060-8586, Hokkaido, Japan Department of Health Promotion, National Institute of Public Health, 2-Chome-3-6 Minami, Wako 351-0104, Saitama, Japan
Taro Kusama Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan; (A.K.); (T.K.); (K.T.); (K.O.) Division of Statistics and Data Science, Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan
Kenji Takeuchi Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan; (A.K.); (T.K.); (K.T.); (K.O.) Division of Statistics and Data Science, Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan
Ken Osaka Department of International and Community Oral Health, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan; (A.K.); (T.K.); (K.T.); (K.O.)

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What is the food like that people choke on? A study on food bolus physical properties under different in vitro oral capacities

People with oral impairments, such as poor denture status, poor muscle strength, and poor salivary secretion, have more difficulties performing oral processes, which results in the risk of choking. In this study, we aimed to understand, in vitro, how different oral impairments can affect the oral processing of food reported as a choking hazard. Six foods that frequently cause choking were selected and studied, varying three in vitro factors at two levels-saliva incorporation amount, cutting activity, and compression action. The median particle size (a50) and the particle size heterogeneity (a75/25) of the food fragmentation, the hardness, and adhesiveness of the bolus formation, and the final cohesiveness of the bolus were studied. The results showed that all the parameters studied varied depending on the food product. High compression reduced a50 (except in mochi that increased) and a75/25 (except in eggs and fish) but increased bolus adhesion and particle aggregation (except for mochi). Regarding cutting activity, when performing a greater number of strokes, the particle size for sausage and egg, and the hardness of the bolus for mochi and sausage were lower. In contrast, for some food products, the bolus adhesiveness (bread) and particle aggregation (pineapple) were higher at a high number of strokes. The amount of saliva also played an important role in the creation of the bolus. When high amounts of saliva were added, the a50 values (mochi) and hardness (mochi, egg, and fish) decreased; and increased the adhesiveness (mochi) and particle aggregation (bread, pineapple, and sausage). When all oral factors are compromised (lack of muscle strength, denture status, and saliva secretion), some food products create a choking hazard as individuals cannot achieve the right particle size, bolus cohesiveness, and mechanical properties of the bolus to be safe to swallow, there is still a need to elaborate a guide, considering all the safety parameters.

In situ quantitative assessment of food oral processing parameters: A review of feasible techniques and devices

Oral processing is a combination of various actions, the detailed description of which has always been the subject of relevant research. By means of imaging technology and sensory evaluation, more knowledge of oral processing have been accumulated. Presently, the advances in sensory technology have added quantitative parameters to the qualitative description of oral processing, which also enriched the specifics of each action. Previous studies have shown that oral processing includes lip closure, dental occlusion, masticatory muscles activity, tongue movement, and swallowing, whose processing contains rich information such as the movement of organ and the intensity of organ contacts. "Quantification" was taken in this review as the basic feature of in situ detection information, the relevant parameters and feasible methods for the quantitative description of each activity was recorded in detail. In addition, basic problems and feasible optimization schemes of the existing in situ detection device are also proposed in the hope of promoting the development of in situ detection device thus providing available information for the description of oral processing.

Comprehensive Dental Treatment under General Anesthesia Improves Mastication Capability in Children with Early Childhood Caries-A One-Year Follow-Up Study

BACKGROUND

Using the granulometry of ready-to-swallow food boluses, this study investigated the evolution of masticatory capability of children with Early Childhood Caries (ECC) after comprehensive dental treatment under general anesthesia (GA).

METHODS

Sixteen children with ECC were assessed before and over one year after dental treatment under GA, in comparison with 12 children with a Healthy Oral State (HOS). Oral health criteria, quality of life, body mass index, and frequency of orofacial dysfunctions were recorded. Masticatory kinematic parameters and median food bolus particle size (D50) at swallowing were assessed while masticating raw carrot (CAR), cheese (CHS), and breakfast cereals (CER). The impact of posterior teeth extractions was analyzed.

RESULTS

Quality of life and orofacial functions improved after dental treatment. Chewing frequency for all three foods increased without reaching the values of children with HOS, while D50 values for CAR and CHS decreased. After one year, children with posterior teeth extractions exhibited higher D50 values for CAR and CHS than children with only conservative treatment. One third of children with ECC were overweight or obese.

CONCLUSIONS

Comprehensive dental treatment improved children's mastication, and their BMI subsequently increased. Links between mastication and nutrition should be investigated further in children.

Designing food for the elderly: the critical impact of food structure

Ageing is an unavoidable progressive process causing many changes of the individual life. However, if faced in an efficient way, living longer in a healthy status could be an opportunity for all. In this context, food consumption and dietary patterns are pivotal factors in promoting active and healthy ageing. The development of food products tailored for the specific needs of the elderly might favour the fulfilment of nutritionally balanced diets, while reducing the consequences of malnutrition. To this aim, the application of a food structure design approach could be particularly profitable, being food structure responsible to the final functionalities of food products. In this narrative review, the physiological changes associated to food consumption occurring during ageing were firstly discussed. Then, the focus shifted to the possible role of food structure in delivering target functionalities, considering food acceptability, digestion of the nutrients, bioactive molecules and probiotic bacteria.

Effects of textured food masticatory performance in older people with different dental conditions

BACKGROUND

Physiological deterioration (aging, poor dental status, and reduced tongue pressure) makes chewing difficult. This study aimed to investigate the chewing patterns of older people with or without dentures, evaluate the textural and masticatory properties of texture-modified radish Kimchi, and investigate the correlation between dental status and tongue pressure. Additionally, differences in the subjective-objective concordance of texture-modified Kimchi were investigated using the preference test.

METHODS

This study included 32 Korean women aged between 65 and 85 years. Masticatory behavior was recorded by electromyography, and tongue pressure was measured using the Iowa Oral Performance Instrument. A preference test, with hardness as the relevant textural property, determined the participants' preferences among the test samples (food with a homogeneous structure-radish Kimchi). To assess preference differences, a questionnaire suitable for older people was designed. The preference for cooked radish Kimchi with various blanching times based on overall acceptability and self-reporting of preference was investigated to develop elderly-friendly food. The subjective scores indicated whether the sample (radish Kimchi) was hard or soft based on the chewing ability of the participants. Dental status, muscle activities, and tongue pressure were considered for the food design with optimized texture. The relationship between subject score and mastication properties were examined using multiple regression analysis.

RESULTS

The number of chews and chewing time increased with hardness, significantly activating the masseter and temporalis muscles. The evaluation of masseter muscle activity, particularly for level-6 radish Kimchi, showed that older people with complete dentures chewed less actively than those with natural teeth (p < 0.05). The older people with natural teeth (18.94 ± 10.27 kPa) exhibited higher tongue pressure than those with complete dentures (10.81 ± 62.93 kPa), and the difference was statistically significant (p < 0.01). Older people preferred food with familiar tastes and textures. An association was found between the subjective hardness score and the objective hardness level. The perceived hardness intensity was linked to the chewing ability of the participant. Denture wearers exhibited a lower chewing ability, and at level 6, they perceived greater hardness of food than those with natural teeth.

CONCLUSIONS

Developing food with a modified texture can bridge the gap between physiological and psychological aspects of food texture; texture-modified radish Kimchi, with limited blanching time, may be favorable for older people.

Effects of a Multifaceted Intervention Program on the Eating Ability of Nursing Home Residents

Oropharyngeal dysphagia is a common problem for nursing home residents that leads to aspiration pneumonia and malnutrition. Musculature surrounding head and neck and tongue strength are crucial for safe and efficient oropharyngeal swallowing. Oral hygiene facilitates the smooth swallowing. The aim of this study was thus to investigate the effects of a multifaceted intervention program which combines the interactive oral activities, tongue strength training and oral cleaning procedure on the eating ability of nursing home residents. A sequential, multiple time series, single-group quasi-experimental research design was used, and 41 residents were recruited to participate in this study. The study was divided into three phases, each lasting two months. In phase 1, the participants were conducting their usual activities, except that the outcome variables were measured on five occasions to obtain baseline data. Phase 2 was a two-month washout period, and phase 3 was the intervention period. Thirty-six residents completed phase 1, and 34 residents completed the phase 3 intervention period. The eight-week phase 3 intervention program comprised three sessions per day, conducted seven days a week, with each session lasting 15–20 min. Outcome variables were measured at weeks 0, 2, 4, 6, and 8 in phases 1 and 3 to evaluate the feasibility of the program. Following the intervention program, controlling for baseline differences, the patients’ tongue strength, food consumption, mealtime duration, oral health, and dysphagia severity were significantly improved in phase 3 relative to phase 1. These improvements lasted through to at least 2 months posttest. The study illustrates that this multifaceted intervention program may be an effective approach for improving the eating ability of nursing home residents.

Relationship among oral health status, bolus formation and food comfortability during consumption of model cheeses in elderly

The aim of this study was to investigate the impact of oral impairment on chewing behaviour, food bolus properties and food comfortability during elderly consumption of model cheeses. Seventy-two elderly persons (aged 66 to 88) was recruited and classified into two groups according to dental status (poor vs. satisfactory). They showed a wide range of salivary flow rates whatever their dental status (stimulated: 0.2-3.8 mL min^-1, resting: 0.1-0.8 mL min^-1). Standardized bites of four model cheeses with an identical composition but different textures (soft, hard, processed and whipped) were tested. The time and number of chewing cycles required to form a bolus were measured. The rheological properties of the bolus were studied, as was saliva moistening. Food comfortability was assessed by means of a questionnaire composed of 5 sections (1-oral comfort, 2-bolus formation, 3-pain, 4-texture and 5-flavour perception). The chewing parameters measured were not modified by the oral health. However, elderly with poor dentition formed harder boluses than elderly with satisfactory dentition. Moreover, for elderly with poor dentition, the quantity of saliva incorporated into the bolus was correlated with the stimulated salivary flow rate, which was not the case for elderly with satisfactory dentition. General oral comfort and its different attributes were poorly associated with the oral health of the elderly. A multifactorial analysis performed on an average cheese showed that food comfortability is independent of changes in the hardness and moistening of the bolus, regardless of dental status. In particular, poor dental status increases the hardness of the bolus without modifying its comfortability.

Texture and texture assessment of thickened fluids and texture-modified food for dysphagia management

Thickened fluids and texture-modified foods are commonly used in the medical management of individuals who suffer from swallowing difficulty (known as dysphagia). However, how to reliably assess texture properties of such food systems is still a big challenge both to industry and to academic researchers. This article aims to identify key physical parameters that are important for objective assessment of such properties by reviewing the significance of rheological or textural properties of thickened fluids and texture-modified foods for swallowing. Literature reviews have identified that dominating textural properties in relation to swallowing could be very different for thickened fluids and for texture-modified foods. Important parameters of thickened fluids are generally related with the flow of the bolus in the pharyngeal stage, while important parameters of texture-modified foods are generally related with the bolus preparation in the oral stage as well as the bolus flow in the pharyngeal stage. This review helps to identify key textural parameters of thickened fluids and texture-modified foods in relation to eating and swallowing and to develop objective measuring techniques for quality control of thickened fluids and texture-modified foods for dysphagia management.

Natural food mastication capability in preschool children according to their oral condition: A preliminary study

This study investigated, for the first time, the masticatory capability of preschool children using natural foods, and the impact of an early oral health alteration (early childhood caries: ECC) on the granulometry of ready-to-swallow food boluses. Thirteen children with ECC were compared to 13 preschool children with a healthy oral condition. Oral health criteria and NOT-S scores (Nordic Orofacial dysfunction Test-Screening) were recorded. For each child, number of masticatory cycles (Nc), chewing time (Ti), and frequency (Fq = Nc/Ti) were recorded during mastication of raw carrot (CAR), cheese (CHS) and breakfast cereals (CER) samples. Food boluses were collected by stopping children at their food-dependent individual swallowing threshold (Nc), and the median food bolus particle size value (D50) was calculated. Correlations were sought between oral health and masticatory criteria. In the ECC group, mean Fq values were significantly decreased for all three foods (p ≤ .001) and mean D50 values were significantly increased (p ≤ .001) compared to the control group (i.e., D50 CAR = 4,384 μm ± 929 vs. 2,960 μm ± 627). These alterations were related to the extent of ECC. The NOT-S mean global score was significantly increased in children with ECC (2.62 ± 1.37 vs. 1 ± 0.91 in the control group, p ≤ .01), due to "Mastication and swallowing" domain impairment. This study gives granulometric normative values for three foods in preschool children and shows the impact of ECC on D50 values. The progression of children's masticatory capability after dental treatment, and the impact of such modifications of sensory input on future eating habits should be explored.

How addition of peach gel particles to yogurt affects oral behavior, sensory perception and liking of consumers differing in age

Addition of particles to foods, such as fruit pieces to dairy products or vegetable pieces to soup, is a convenient approach to alter nutritional composition, appearance, perception and acceptance. The aim of this study was to investigate the effect of addition of peach gel particles to yogurt on oral behavior, sensory perception and liking of consumers differing in age. One homogeneous yogurt and seven yogurts with peach gel particles were prepared. The added peach gel particles varied in size, fracture stress, or concentration. Oral behavior of n = 62 healthy Dutch, young adults (21 ± 2 years) and n = 62 healthy Dutch elderly (70 ± 5 years) participants was characterized by video recordings. Yogurts' sensory properties and liking were scored on nine-point scales. Elderly consumed yogurts with higher number of chews and longer consumption time leading to lower eating rate than young adults. Addition of particles, regardless of characteristics, increased number of chews, consumption time, and decreased eating rate up to 60% for both consumer groups, with an average decrement of 110 g/min for young and of 63 g/min for elderly consumers. With increasing peach gel hardness and concentration, the number of chews and consumption time increased while eating rate decreased. Peach gel particle size did not affect oral behavior. Sensory perception of yogurts with added peach gel particles was similar for healthy young adult and healthy elderly. Only small differences in sensory perception were observed between the young adults and elderly for flavor attributes, crumbliness, juiciness, and perceived particle size. Similarly, minor differences in liking of a few yogurts with peach pieces were observed between both consumer groups. Thus, healthy ageing seems to affect sensory perception of semi-solid foods to a limited extent only. We conclude that changes in food texture by addition of particles can be used as a strategy to steer eating rate and potentially impact food intake of young adult and elderly consumers while maintaining or enhancing food palatability. Additionally, particle characteristics can be modified to target specific consumer groups that might differ in eating capabilities.

Effects of an Eating Ability Promotion Program for Community-Dwelling Older Adults

OBJECTIVE

Taiwan is projected to become a super-aged society in 2026. Taiwan's government introduced an innovative preventive care policy to improve aging-related conditions in 2017. In this study, we examine the effectiveness of an eating ability promotion program (EAPP) on the physical and mental performance of community-dwelling older adults.

DESIGN

Single-masked, cluster randomized trial.

SETTING

Two community care stations in Taichung, Taiwan.

PARTICIPANTS

Volunteers were recruited from these 2 community care stations. The 70 participants were aged ≥60 years, able to walk independently and take care of themselves, and understood Mandarin or Taiwanese.

INTERVENTION

The volunteers were randomly assigned to an intervention; 40 participated in EAPP training courses (experimental group) and 30 participated in originally scheduled activities only (control group). EAPP training courses were conducted in the care stations 4 hours per week for 12 weeks (for a total of 48 hours).

MEASURES

The physical performance outcomes were oral health, nutritional status, and fragility, assessed using the Oral Health Assessment Tool, the Mini Nutritional Assessment, and the Study of Osteoporotic Fractures fragility index, respectively. Cognitive function was evaluated with the Mini-Cog test. Measurements were performed at baseline, at the end of the 12-week intervention, and 1 month later.

RESULTS

Following the EAPP intervention, controlling for baseline differences, the oral health (F = 33.29, P < .001), nutritional status (F = 7.30, P = .009), and scale of fragility (F = 19.05, P < .001) of the participants in the experimental group were significantly better than those reported in the control group.

CONCLUSIONS AND IMPLICATIONS

Results of this preliminary study suggest that the EAPP intervention may be an effective approach for improving oral health, nutritional status, and fragility in community-dwelling older adults. This training course, which provides clear and concise information regarding eating ability strategies, should undergo further evaluation and, if demonstrated to be effective and cost-effective in broader trials, may be useful in promoting healthy living.

Acceptability of tropical fruit pulps enriched with vegetal/microbial protein sources: viscosity, importance of nutritional information and changes on sensory analysis for different age groups

The combination of products traditionally consumed with other components with the alleged classification of functional food has become a continuous reality, if not a necessity. This article investigated the supplementation of tropical fruit pulps (acerola-Malpighia emarginata, guava-Psidium guajava, passion fruit-Passiflora edulis and mandarin-Citrus reticulata), with 5-10% (m/V) on vegetal/microbial protein sources (soy protein, beer yeast and bee pollen). Viscosity and colour analysis were carried out and differences between fruit pulp with no addition and those supplemented were verified, with a specific importance to soy protein, which increased 5-10 times pulps viscosity, while the remaining supplemented formulations, 1.5-3 times. Between the sensory factors (colour, flavour, aroma and appearance), flavour significantly influenced the acceptance of the product (p < 0.05). The nutritional information provided to tasters, as well as to specific age groups (children, elderly and youngsters/adults), significantly increased the product's acceptance; with values ranging between 70 and 80% in some cases, demonstrating the importance of cognitive response on those factors.

Dynamic Oral Texture Properties of Selected Indigenous Complementary Porridges Used in African Communities

Child malnutrition remains a major public health problem in low-income African communities, caused by factors including the low nutritional value of indigenous/local complementary porridges (CP) fed to infants and young children. Most African children subsist on locally available starchy foods, whose oral texture is not well-characterized in relation to their sensorimotor readiness. The sensory quality of CP affects oral processing (OP) abilities in infants and young children. Unsuitable oral texture limits nutrient intake, leading to protein-energy malnutrition. The perception of the oral texture of selected African CPs (n = 13, Maize, Sorghum, Cassava, Orange-fleshed sweet potato (OFSP), Cowpea, and Bambara) was investigated by a trained temporal-check-all-that-apply (TCATA) panel (n = 10), alongside selected commercial porridges (n = 19). A simulated OP method (Up-Down mouth movements- munching) and a control method (lateral mouth movements- normal adult-like chewing) were used. TCATA results showed that Maize, Cassava, and Sorghum porridges were initially too thick, sticky, slimy, and pasty, and also at the end not easy to swallow even at low solids content—especially by the Up-Down method. These attributes make CPs difficult to ingest for infants given their limited OP abilities, thus, leading to limited nutrient intake, and this can contribute to malnutrition. Methods to improve the texture properties of indigenous CPs are needed to optimize infant nutrient intake.

Oral processing in elderly: understanding eating capability to drive future food texture modifications

Ageing population suffer from increased risk of malnutrition which is a major determinant of accelerated loss of autonomy, adverse health outcomes and substantial health-care costs. Malnutrition is largely attributed to reduced nutrient intake which may be associated with several endogenous factors, such as decline of muscle mass, oral functions and coordination that can make the eating process difficult. From an exogenous viewpoint, nutritionally dense foods with limited innovations in food texture have been traditionally offered to elderly population that negatively affected pleasure of eating and ultimately, nutrient intake. Recent research has recognised that older adults within the same age group are not homogenous in terms of their preferences, nutritional needs, capabilities and impediments in skill-sets. Hence, a new term eating capability (EC) has been coined to describe various quantifiable endogenous factors in the well-coordinated eating process that may permit characterisation of the capabilities of elderly individuals in food handling and oral processing. This review covers current knowledge on EC focusing on parameters, such as hand and oro-facial muscle forces. Although limited in literature, EC score measured using a comprehensive toolkit has shown promise to predict eating difficulty perception and oral processing behaviour. Further systematic studies are required to explore relationships between individual/multiple constituents of EC and oral comfort. Such knowledge base is needed to underpin the creation of next generation personalised texture-modified foods for elderly population using sophisticated technologies, such as 3D printing to enhance eating pleasure, increase nutrient intake that will ultimately contribute to tackling malnutrition.

The Association of Poor Oral Health Parameters with Malnutrition in Older Adults: A Review Considering the Potential Implications for Cognitive Impairment

Poor dental status and chewing deficiencies have been associated with cognitive decline. Altered dietary habits and malnutrition have been suggested as linking mechanisms. The aim of the present review was thus to investigate if poor oral health, and in particular tooth loss and impaired masticatory function, may affect dietary selection and nutritional intake in older adults, and moreover, to assess if prosthodontic dental care may improve nutritional status. Extensive tooth loss may impair masticatory function. Several studies in older populations have shown that severe tooth loss and masticatory impairment are associated with limited consumption of various food types (especially fruits and vegetables), increased consumption of sugary and easy-to-chew foods, and lower dietary intake of fibre and vitamins. However, these findings are not consistently reported, due to methodological variation among studies, potential adverse causalities, and the multifactorial nature of food choices. On the other hand, a few interventional studies revealed that prosthetic rehabilitation of missing teeth, when accompanied by dietary counselling, may improve dietary habits and nutritional intake. Further research is required to improve current knowledge of these associations. Under the limitations of the current study, a functional dental arch of natural or artificial teeth is important for maintaining adequate chewing efficiency and ability, but this only partly contributes to food choices and nutritional status. The multifactorial nature of food choices necessitates the interprofessional collaboration of dental professionals, dietetics practitioners, and primary care providers to improve dietary habits and nutritional intake.

Oral declines and mastication deficiencies cause alteration of food bolus properties

In the elderly, masticatory function often presents failure in certain oral tasks due to impairment such as decline in muscular force, jaw or tongue motility, neuro-muscular coordination, tooth damage, malocclusion and saliva production. Great disparity is observed in the various and potentially cumulative oral declines that occur with ageing. Such difficulties may have an impact on food consumption and nutritional status. To obtain better understanding of the consequences of several oral deficiencies, a series of swallowable boluses were prepared in vitro with the AM² masticator apparatus with normal and deficient programming. Physiological normal mastication (NM) was simulated using in vivo data from healthy subjects. Chewing deficiencies were reproduced by alteration of NM programming to perform different levels and combinations of force loss, lack of saliva and decrease in the motility of oral elements. Poultry meatballs were used as test-food. Particle size distribution in the food bolus was measured by sieving and rheological features (hardness, cohesiveness and elasticity) were assessed with a TPA test. Compared to the NM outcome, significant and gradual deterioration of the food bolus was observed and associated with alteration in force, saliva and motility. Combinations of several failures led to greater or cumulative deficiencies in swallowable bolus properties. For the elderly presenting a high prevalence of various oral injuries, tailoring textured food cannot be ignored as a solution for remedying deficiencies and favoring the formation of a safe-swallowable bolus, which is an essential vector of nutrients. Knowing the impacts of oral injuries on the food bolus is obviously a requisite for developing diet strategies, including nutritional items for specific populations.

Perception and measurement of food texture: Solid foods

There is still a gap between instrumental measurement and sensory evaluation because of the complexity of food texture in spite of many efforts. In sensory evaluation, the terms describing the texture should be well understood by panelists, which poses a problem of establishing lexicons and training panelists. In the instrumental measurement, more efforts are required to understand the large deformation and fracture behavior of foods. The texture profile analysis (TPA) proposed by Alina Szczesniak, Malcolm Bourne, and Sherman has been applied to many foods, and was useful to develop the understanding of textures. But sometimes confusion of the interpretation of TPA parameters appeared. Many new techniques have been introduced to quantify TPA parameters. Recent efforts to fill the gap between sensory evaluation and instrumental measurements, human measurements, or physiological measurements have been introduced. This endeavor is an effort of synthesizing the dentistry and biomedical approach, sensory and psychological approach, and material science approach, and therefore, the collaboration among these disciplines is necessary. This manuscript mainly discusses texture studies for solid foods.

PRACTICAL APPLICATIONS

To fill the gap between the sensory evaluation and the instrumental measurement of texture, it is necessary to examine the physical change of foods during the oral processing. This will give us the designing principle of palatable and safe foods.

Relationships of oral comfort perception and bolus properties in the elderly with salivary flow rate and oral health status for two soft cereal foods

The aim of this study was to investigate food oral processing and bolus formation in the elderly population, and their relationship with the perception of oral comfort, for two soft cereal products of different composition: sponge-cake and brioche. Twenty subjects aged 65 and over participated in the study. They were classified in two groups according to dental status (poor vs. satisfactory) and presented various stimulated salivary flow rate (SSF) in each group. Food bolus properties (hydration ratio and apparent viscosity) were characterized after three chewing stages for both groups. Results showed that chewing duration did not depend on food product but rather on physiology: subjects with a poor dental status had a shorter chewing duration. For each chewing stage, sponge-cake boli showed a higher hydration ratio than brioche boli, which showed higher apparent viscosity. For sponge-cake, perception of oral comfort was primarily driven by SSF rate, irrespective of the dental status. In the case of brioche, oral comfort was also partially explained by SSF in the case of subjects with poor dental status. This result suggests that perception of oral comfort in brioche could be driven by product related attributes rather than oral health. For both foods, a phenomenological model of bolus viscosity as a function of stimulated salivary flow and chewing duration was proposed.

Clinical applications of IDDSI framework for texture recommendation for dysphagia patients

Dysphagia is a highly prevalent eating and swallowing disorder among elderly people, impacting negatively on the health and well-being of those afflicted. With increasing populations of elderly people, food industries are under growing pressure to produce appropriately texture-modified food for safe consumption by these vulnerable populations. Recently published International Dysphagia Diet Standardisation Initiative (IDDSI) framework provides a new global guideline on texture modification and standardization for dysphagia patients. This work was designed to test the feasibility of IDDSI framework for clinical applications by assessing the correlation between swallowing capability of dysphagia patients and the IDDSI texture levels. Altogether 26 elderly subjects were recruited and assessed for their dysphagia grades using the Water Drinking Test. Subjects were provided with fluid samples constituted at different consistencies from a commercial product and swallowing performance (time of swallowing, number of swallows, and number of coughs) was monitored and recorded. Correlations among swallowing capability parameters were observed. Most importantly, results from this work clearly demonstrated that the severity of dysphagia by water-based swallow tests correlates positively with the IDDSI fluid thickness aimed at reducing dysphagia symptoms in those patients, confirming the reliability and feasibility of IDDSI framework for clinical applications.

PRACTICAL APPLICATIONS

Swallowing disorder or dysphagia occurs commonly among many elderly people and imposes negative impacts on their health and well-being. Medical professionals can diagnose eating and swallowing capability in a qualitative manner, but have difficulty in making diet recommendation because of the lack of texture guidance. This work confirmed the feasibility of IDDSI framework for clinical and bedside applications. The correlation between the capability grades of swallowing and IDDSI texture levels established in this work provides a useful measure for such applications.