The effect of aging on mastication and swallowing parameters according to the hardness change of solid food

Chewing Well Modulates Pharyngeal Bolus Transit During Swallowing in Healthy Participants

Mastication is controlled by central pattern generator in the brainstem and can be modulated by volition. The aim of this study was to investigate the effect of chewing well on swallowing. Twenty-six healthy participants were instructed to eat 8, 12, and/or 16 g of steamed rice with barium sulphate under the following two conditions: chewing freely task (CF; chewing naturally in their usual manner) and chewing well task (CW; chewing the food with a request to "chew well"). We evaluated bolus transport and swallowing movement using videofluoroscopy and electromyography of the masseter, suprahyoid and thyrohyoid muscles. The chewing time and pharyngeal transit time (PTT) at the first swallow showed high reproducibility in both CF and CW. PTT for CW was significantly shorter and longer than CF in 12 and 16 g, respectively. In 12 g, CW increased the pharyngeal bolus velocity and decreased thyrohyoid EMG activity during swallowing compared with CF. In 16 g, the difference between CW and CF in the estimated swallowed bolus volume was positively correlated with that in upper esophageal sphincter transit duration. We speculate that CW modulates PTT during swallowing depending on the mouthful volume.

Sensory properties of thickened tomato soup enhanced with different sources of protein (whey, soy, hemp, and pea)

Thickened soup formulations were created with different proteins (hemp, soy, pea, and whey) to improve protein and fluid intake. The formulations consisted of a control soup, and soups with 6% whey protein, 6% hemp protein, 6% pea protein, and 6% soy protein by volume. The suitability of the samples for those living with dysphagia was evaluated using the international dysphagia diet standardization initiative (IDDSI) spoon tilt test and a sensory trial (51 older adults and 51 younger adults). The sensory trial used nine-point hedonic scales and check-all-that-apply to evaluate the different formulations. The sample with the whey addition was not significantly different than the control in terms of liking of flavor and texture, but it decreased the participants' overall liking. The hemp, pea, and soy decreased overall liking as well as liking of flavor and texture. They were associated with off-flavors, aftertaste, and astringency. The responses from the older and younger adults were compared and significant differences were found in their liking of the texture, with the older adults finding the formulations' texture significantly more acceptable. Overall, the study identified that hemp, pea, and soy did not create acceptable thickened soup formulations and the hemp and pea formulations did not achieve a consistency level that is acceptable for those living with dysphagia.

Mineral bioaccessibility in 3D printed gels based on milk/starch/ĸ-carrageenan for dysphagic people

Dysphagia is a condition that affects the ability to chew and swallow food and beverages, having a major impact on people's health and wellbeing. This work developed gel systems with a customized texture suitable for intake by dysphagic people using 3D printing and milk. Gels were developed using skim powdered milk, cassava starch (native and modified by the Dry Heating Treatment (DHT)), and different concentrations of kappa-carrageenan (ĸC). The gels were evaluated in relation to the starch modification process and concentration of gelling agents, 3D printing performance, and suitability for dysphagic people (following both the standard fork test described by the International Dysphagia Diet Standardization Initiative (IDDSI), and also using a new device coupled to a texture analyzer). Moreover, the best formulations were evaluated for mineral bioaccessibility through simulated gastrointestinal digestion based on INFOGEST 2.0 standardized method. The results showed that ĸC had a dominant effect compared to the DHT-modified starch on gel texture, 3D printing performance, and fork tests. The gels obtained by molding or 3D printing resulted in different behaviors during the fork test, which was associated with the gel extrusion process that breaks down their initial structure. The strategies applied to tailor the texture of the milk did not affect the mineral bioaccessibility, which was kept high (>80%).

Mechanical Properties, Microstructure, and In Vitro Digestion of Transglutaminase-Crosslinked Whey Protein and Potato Protein Hydrolysate Composite Gels

The production of animal protein usually leads to higher carbon emissions than that of plant protein. To reduce carbon emissions, the partial replacement of animal protein with plant protein has attracted extensive attention; however, little is known about using plant protein hydrolysates as a substitute. The potential application of 2 h-alcalase hydrolyzed potato protein hydrolysate (PPH) to displace whey protein isolate (WPI) during gel formation was demonstrated in this study. The effect of the ratios (8/5, 9/4, 10/3, 11/2, 12/1, and 13/0) of WPI to PPH on the mechanical properties, microstructure, and digestibility of composite WPI/PPH gels was investigated. Increasing the WPI ratio could improve the storage modulus (G') and loss modulus (G″) of composite gels. The springiness of gels with the WPH/PPH ratio of 10/3 and 8/5 was 0.82 and 0.36 times higher than that of the control (WPH/PPH ratio of 13/0) (p < 0.05). In contrast, the hardness of the control samples was 1.82 and 2.38 times higher than that of gels with the WPH/PPH ratio of 10/3 and 8/5 (p < 0.05). According to the International Organization for Standardization of Dysphagia Diet (IDDSI) testing, the composite gels belonged to food level 4 in the IDDSI framework. This suggested that composite gels could be acceptable to people with swallowing difficulties. Confocal laser scanning microscopy and scanning electron microscopy images illustrated that composite gels with a higher ratio of PPH displayed thicker gel skeletons and porous networks in the matrix. The water-holding capacity and swelling ratio of gels with the WPH/PPH ratio of 8/5 decreased by 12.4% and 40.8% when compared with the control (p < 0.05). Analysis of the swelling rate with the power law model indicated that water diffusion in composite gels belonged to non-Fickian transport. The results of amino acid release suggested that PPH improved the digestion of composite gels during the intestinal stage. The free amino group content of gels with the WPH/PPH ratio of 8/5 increased by 29.5% compared with the control (p < 0.05). Our results suggested that replacing WPI with PPH at the ratio of 8/5 could be the optimal selection for composite gels. The findings indicated that PPH could be used as a substitute for whey protein to develop new products for different consumers. Composite gels could deliver nutrients such as vitamins and minerals to develop snack foods for elders and children.

Nutritional Status and Sarcopenia in Nursing Home Residents: A Cross-Sectional Study

OBJECTIVE

This study aimed to assess the nutritional status and sarcopenia in older people living in nursing homes.

METHODS

This cross-sectional study enrolled 386 older adults in nursing homes in Hunan Province, China. Assessments included the Mini Nutritional Assessment Short Form for nutrition risk, Dietary Diversity Score for dietary diversity and Mini Mental State Examination for cognitive status. Sociodemographic (e.g., age, sex and educational level), health-related characteristics (e.g., food intake, self-care status and medication), body composition (e.g., body mass index [BMI], protein, body fat mass [BFM], percent body fat [PBF], skeletal muscle index [SMI] and total body water [TBW]) and anthropometric parameters data (e.g., calf circumference [CC], upper arm circumference [UAC], handgrip and gait speed) were also collected. Malnutrition and their associated risk were analyzed by multivariable Poisson regression analysis.

RESULTS

In total, 32.4% of participants (n = 125) were at risk of malnutrition and 49.7% (n = 192) suffered from sarcopenia. Nutritional status was positively associated with age (risk ratio [RR] = 1.03), sarcopenia (RR = 1.88), tooth loss affecting food intake (RR = 1.45), low self-care status (RR = 1.82) and moderate/inadequate dietary diversity (RR = 2.04) and negatively associated with one child (RR = 0.27), BMI (RR = 0.82), protein (RR = 0.76), BFM (RR = 0.91), PBF (RR = 0.94), SMI (RR = 0.65), TBW (RR = 0.94), CC (RR = 0.89) and UAC (RR = 0.86).

CONCLUSIONS

Age, number of children, sarcopenia, food intake, self-care status, dietary diversity and body composition were associated with malnutrition among nursing home residents. For vulnerable groups, researchers should focus on raising the body composition indicators, such as BMI, protein, BFM, SMI and TBW and measuring CC and UAC for initial screening.

Effects of Food and Liquid Properties on Swallowing Physiology and Function in Adults

Foods and liquids have properties that are often modified as part of clinical dysphagia management to promote safe and efficient swallowing. However, recent studies have questioned whether this practice is supported by the evidence. To address this, a scoping review was conducted to answer the question: "Can properties of food and liquids modify swallowing physiology and function in adults?" Online search in six databases yielded a set of 4235 non-duplicate articles. Using COVIDENCE software, two independent reviewers screened the articles by title and abstract, and 229 full-text articles were selected for full-text review. One-hundred eleven studies met the inclusion criteria for qualitative synthesis and assessment of risk of bias. Three randomized controlled trials and 108 non-randomized studies were analyzed. Large amounts of variability in instrumental assessment, properties of food and liquids, and swallowing measures were found across studies. Sour, sweet, and salty taste, odor, carbonation, capsaicin, viscosity, hardness, adhesiveness, and cohesiveness were reported to modify the oral and pharyngeal phase of swallowing in both healthy participants and patients with dysphagia. Main swallow measures modified by properties of food and liquids were penetration/aspiration, oral transit time, lingual pressures, submental muscle contraction, oral and pharyngeal residue, hyoid and laryngeal movement, pharyngeal and upper esophageal sphincter pressures, and total swallow duration. The evidence pooled in this review supports the clinical practice of food texture and liquid consistency modification in the management of dysphagia with the caveat that all clinical endeavors must be undertaken with a clear rationale and patient-specific evidence that modifying food or liquid benefits swallow safety and efficiency while maintaining quality of life.

Meat texture modification for dysphagia management and application of hydrocolloids: A review

Dysphagia is a medical condition that describes the difficulty of swallowing food, and texture modified food (TMF) is the best intervention for dysphagia. The relevant guidelines to identify dysphagia food are provided by the International Dysphagia Diet Standardization Initiative (IDDSI). Developing texture modified meat is a challenging task due to its fibrous microstructure and harder texture. Various meat tenderization attempts are therefore evaluated in the literature. Meat texture modification for dysphagia is not just limited to tenderization but should be focused on safe swallowing attributes as well. The application of hydrocolloids for designing TMF has a major research focus as it is a cost-effective method and offers an opportunity for careful control. The present review focuses on the meat texture modification attempts that have been used in the past and present, with special attention to the use of hydrocolloids. Several studies have shown improvements in texture upon the addition of various hydrocolloids; however, few studies have attempted to develop texture modified meat for people with dysphagia. This area has to be further developed along with the sensory evaluations conducted with the dysphagia population, to validate the industrial application of hydrocolloids to TMF.

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.

Instrumental texture assessment of IDDSI texture levels for dysphagia management. Part 2: Texture modified foods

Texture-modified foods and thickened fluids play a major role in clinical treatment for individuals who suffer from swallowing difficulties (known as dysphagia). International Dysphagia Diet Standardization Initiative (IDDSI) developed a standardized terminology and description for texture-modified foods and thickened fluids to allow dysphagia patients to receive the correct consistency of food/drink. While the IDDSI framework provides a consistent texture description (Levels 0-7) and is widely accepted as an international standard, testing and assessment of IDDSI texture level are qualitative in nature and subjective in manner. These methods were proposed primarily for use by frontline carers, but are not most ideal for industrial purposes of quality control of such products. Therefore, the main aim of this work was to develop a quantitative instrumental method that best describes IDDSI levels as an objective framework. A set of test samples, including commercially available instant mashed potato, baby rice cereal, and cooked potato cubes of varying texture, were prepared. Two IDDSI measuring techniques, fork pressure test and spoon tilt test, were used to evaluate texture grades of these samples. Puncture and compression tests based on texture analyzer were used to assess cohesiveness, adhesiveness, firmness, and hardness for each food category (Levels 4-7). Thresholds of cohesiveness and adhesiveness, as well as bands of acceptable firmness and hardness for each food category were clearly identified and are proposed as objective complements to the IDDSI framework.

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.

Instrumental and sensory techniques to characterize the texture of foods suitable for dysphagic people: A systematic review

The interest to characterize texture-modified foods (TMFs) intended for people with oropharyngeal dysphagia (OD) has grown significantly since 2011. Several instrumental and sensory techniques have been applied in the analysis of these foods. The objective of the present systematic review was to identify the most appropriate techniques, especially for the food industry and clinical setting. The search was carried out in three online databases according to the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA). Across the multiple trials reviewed, Texture Profile Analysis and the Uniaxial Compression Test were most used as the instrumental technique for solid foods, and the Back Extrusion Test for fluid and semisolid foods. All trials used descriptive analysis as the sensory technique. However, the experimental conditions of the trials lacked standardization. Consequently, the results of the trials were not comparable. To properly characterize the texture of TMFs intended for OD by each technique, an international consensus is needed to establish standardized experimental conditions. Methods based on these techniques should also be validated by collaborative studies to verify repeatability, replicability, and reproducibility.

Relationship between Food Crushing and Oral Function in Older Adults Requiring Nursing Home Care: A Pilot Study

We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.

Improvement of chewing and swallowing risks in community-dwelling older adults using texture-modified food

BACKGROUND/OBJECTIVES

SUBJECTS/METHODS

RESULTS

CONCLUSIONS

Duração da mastigação e da fase oral da deglutição em idosos com diferentes condições dentárias: análise clínica

RESUMO Objetivo: mensurar o tempo total da mastigação e da fase oral da deglutição em idosos saudáveis, considerando diferentes consistências alimentares, a presença de dentes naturais e o tipo de reabilitação oral protética, bem como realizar comparação entre as condições dentárias e as consistências. Métodos: estudo transversal com 57 idosos saudáveis, entre 60 e 82 anos, distribuídos em grupo dentado (D) (n=15) e grupos reabilitados: próteses parciais fixas ou removíveis em uma ou ambas as arcadas (PP) (n=15); prótese total removível maxilar e mandibular (PTR) (n=15); prótese total - prótese removível superior e prótese implanto-suportada inferior (PTIS) (n=12). O tempo de duração (segundos) da mastigação e da fase oral da deglutição foi medido nas consistências: sólida (pão francês), pudim (10 ml) e líquida (10 ml). Resultados: idosos dentados saudáveis apresentaram os intervalos: líquido=1,07±0,35 s; pudim=3,48±1,76 s; e sólido=27,88±7,11 s. Foram observadas diferenças estatisticamente significativas entre os grupos D e PTIS (p=0,0056) e entre D e PTR (p=0,0056) para líquido. Para todos os grupos, houve aumento estatisticamente significante entre as consistências líquida e sólida e entre pastosa e sólida (p<0,001). Conclusões: idosos dentados apresentaram menor tempo de fase oral da deglutição para líquidos do que idosos edêntulos totais reabilitados, mas não diferente dos idosos com prótese parcial. O tempo de mastigação e deglutição do alimento sólido foi maior que o das demais consistências, independente da condição dentária.

Duration of mastication and oral phase of swallowing in the elderly with different dental conditions: a clinical analysis

ABSTRACT Purpose: to measure the total time of mastication and oral phase of swallowing in healthy elderly people, considering different food consistency, the presence of natural teeth, and the type of prosthetic oral rehabilitation, as well to compare dental conditions and consistencies. Methods: a cross-sectional study with 57 healthy elderly people, aged between 60 and 82 years, divided into: dentate group (D) (n=15); and rehabilitated groups; PD: fixed or removable partial dentures in one or both arches (n=15); CRD: maxillary and mandibular complete removable dentures (n=15); ISCD: complete dentures - maxillary removable denture and mandibular implant-supported dentures (n=12). The duration time (seconds) of chewing and of the oral phase of swallowing was measured in the consistencies: solid (a roll slice), pudding (10 ml) and liquid (10 ml). Results: healthy dentate elderly subjects had the following intervals: liquid=1.07±0.35 s; pudding=3.48±1.76 s; and solid=27.88±7.11 s. Statistically significant differences were observed between the D and ISCD groups (p=0.0056) and between D and CRD (p=0.0056) for liquid. For all groups, there was a statistically significant increase between liquid and solid consistencies and between pasty and solid ones (p<0.001). Conclusions: the dentate elderly had shorter oral phase time of swallowing for liquids than the rehabilitated edentulous elderly, but not different from the elderly with partial dentures. Chewing and swallowing time for solid food was longer than that for the other consistencies, regardless of dental condition.

Correlation between Instrumental and Sensory Properties of Texture Modified Carrot Puree

This study was undertaken to determine the correlation between instrumental and sensory evaluation on texture modified carrot puree. Texture modified foods (TMF) are prescribed to dysphagia individuals to aid in the oral manipulation and facilitate swallowing of food. There is a lack of correlation between instrumental measurements and sensory attributes on TMF. Understanding this correlation will aid in the formulation of safe foods with desired sensory properties for dysphagia patients. Instrumental measurements of carrot purees were performed by back extrusion method using a texture analyser and the attributes obtained were firmness, consistency, cohesiveness and adhesiveness. Quantitative Descriptive Analysis (QDA) with eight trained panellists was employed to characterize the texture of the carrot puree based on seven sensory attributes: Firmness, viscous, adhesive (mouth), smoothness, adhesive (throat), rate of breakdown, difficulty to swallow. Five thickeners, namely gellan gum, xanthan gum, Suberakaze, UNI-PURE® Dys-sperse instant thickener, ULTRA-SPERSE® M Starch were evaluated against carrot puree without any thickener as control. The correlation results obtained from texture analysis and sensory evaluation were statistically significant (p < 0.05). The firmness attributes from instrumental and sensory results were positively correlated. The consistency parameter was positively correlated to sensory attribute viscous and negatively correlated to smoothness. The sensory attribute rate of breakdown was negatively correlated to instrumental parameter of cohesiveness. Lastly, instrumental adhesiveness was positively correlated to sensory attributes adhesive to mouth and throat, and difficulty to swallow. The correlation results showed a well-designed instrumental technique can be used to understand the impact of thickeners on TMF for dysphagia subjects. This article is protected by copyright. All rights reserved.

Assessment of masticatory function in older individuals with bimaxillary implant-supported fixed prostheses or with a natural dentition: A case-control study

STATEMENT OF PROBLEM

A clinical assessment of the masticatory performance of edentulous people treated with bimaxillary implant-supported fixed prostheses is lacking.

PURPOSE

The purpose of this case-control study was to compare the masticatory performance of edentulous people treated with bimaxillary implant-supported fixed prostheses to that of those with a natural dentition by using a simplified comminution test with hard viscoelastic test food and a mixing ability test.

MATERIAL AND METHODS

Thirty-six participants were recruited and divided into 2 equal groups (n=18) based on their dental status. The experimental group (7 women, mean ±standard deviation age=69.8 ±7.5 years) had bimaxillary implant-supported fixed prostheses, and the control group (9 women, mean ±standard deviation age=68.3 ±5.6 years) had a natural dentition. A hard viscoelastic food comminution test and a mixing ability test with 2-colored chewing gum were performed in both groups. The number and total area of the particles during the comminution test and the variance of hue during the mixing ability test were measured. The data were analyzed with the parametric (paired t test) and nonparametric (Mann-Whitney U) tests to assess differences between the groups (α=.05).

RESULTS

The experimental group exhibited significantly fewer pieces in the food comminution test than the control group (P=.001). The experimental group also showed significantly higher variance of hue values than the control group (P<.001).

CONCLUSIONS

Patients treated with bimaxillary implant-supported prostheses had reduced masticatory performance in comparison to those with a natural dentition, despite having been provided with satisfactory and well-functioning prostheses.

Understanding the oral processing of solid foods: Insights from food structure

Understanding the relationship between the structure of solid foods and their oral processing is paramount for enhancing features such as texture and taste and for improving health-related factors such as management of body weight or dysphagia. This paper discusses the main aspects of the oral processing of solid foods across different categories: (1) oral physiology related to chewing, (2) in-mouth food transformation, (3) texture perception, and (4) taste perception, and emphasis is placed on unveiling the underlying mechanisms of how food structure influences the oral processing of solid foods; this is exemplified by comparing the chewing behaviors for a number of representative solid foods. It highlights that modification of the texture/taste of food based on food structure design opens up the possibility for the development of food products that can be applied in the management of health.

Influence of thickening agents on rheological properties and sensory attributes of dysphagic diet

Dysphagia is the difficulty during the progression of the bolus from the mouth to the stomach. Modifying the texture of the food is a fundamental factor for safe swallowing in patients with dysphagia since inadequate consistency can result in complications. To personalize and develop diets for dysphagia, understanding, and controlling the rheological and sensory properties of thickeners is useful. This review examines the different types of thickeners used to modify the texture of foods, as well as their influence on rheological properties and sensory attributes to efficiently manage the diet in dysphagia. The study discusses characteristics such as: hardness, viscosity, viscoelasticity, as well as sensory attributes related to rheology. The thickeners xanthan gum, methylcellulose, carboxymethylcellulose, guar gum, linseed, and chia, carboxymethylated curdlan, and konjac glucomannan were reviewed in this work. Sensory evaluations of different foods have already been carried out on some products such as: meats, carrots, soups, pates, and timbales with their modified textures. The sensory attributes measured among hydrocolloids are strongly correlated with rheological parameters. Dysphagic diets should have less hardness and adherence, but with adequate cohesiveness to facilitate chewing, swallowing to protect from aspiration and reduction of residues in the oropharynx. The use of a single type of thickener may not be ideal, their mixtures and synergistic effect can improve the viscous and elastic characteristics of foods, to obtain safe food to swallow and to improve the sensory interest of dysphagic patients. Personalized recommendations with follow-up on swallowing approaches, respecting patient's individuality, explaining thickening agents' differences would be pertinent.

Physical properties of a model set of solid, texture-modified foods

Those suffering from swallowing disorders, or dysphagia, require texture-modified foods for safe swallowing. The texture is modified according to the severity of the disorder, as maintained by the guidelines outlining classes of texture-modified foods, ranging from viscous soups to soft, solid foods. As a basis for studies of bolus rheology and oral response of solid texture-modified foods, a set of well-defined, solid foods has been identified and characterized regarding texture and physical properties. Gelled food is compared to both the firmer timbale class and to the corresponding regular food. Foods eaten at room temperature were chosen to avoid temperature effects: bread, cheese, tomato, and the combination into a sandwich. All foods were tested as gel, timbale, and regular food. The texture was determined by compression and penetration tests, thereby showing a decrease in strength (compression stress), stiffness (modulus), and penetration force for increased degree of modification. The moisture content increased with increased degree of modification. The structural change from room to oral temperature was monitored by the complex shear modulus that showed a decrease with increasing temperature. Cheese and the gelatine-based tomato gel showed a distinct melting when the temperature was increased to 37°C. The texture-modified foods were softer and moister in all aspects as compared to the regular foods, which follows the intended modification. The classes for the texture-modified foods were qualitatively comparable to other national classification systems with regard to solid foods, but there is a lack of objective, physics-based classification of texture, especially for solid, texture-modified foods.

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.

Aging and Sex Effects on Mastication Performance in Healthy, Nondysphagic, Community-Dwelling Adults

Purpose This study investigated the impact of age and sex on mastication performance in healthy, nondysphagic, community-dwelling adults as observed during videofluoroscopy. Method Videofluoroscopic swallowing study imaging and mastication performance metrics (cycles, duration) were used to evaluate 185 healthy individuals (102 women, 83 men) aged 21-89 years. Results A significant effect of age on mastication cycles was not observed; however, a significant but weak effect of age on mastication duration was found. Female participants were observed to have significantly more mastication cycles and longer mastication durations compared to male participants. Three behavioral patterns of mastication performance emerged. Conclusions The results of this study contribute to normative data of mastication performance. An individual's sex was found to have a significant effect on mastication performance, although, in contrast to previous studies, age was not observed to significantly alter mastication performance. Differences in study methodologies likely explain the latter finding.

Sensory Profile of Adults with Reduced Food Intake and the Potential Roles of Nutrition and Physical Activity Interventions

The sensory profile, referring to sight, smell, taste, hearing, and touch, plays an essential role in optimizing the habitual intake of energy and macronutrients. However, specific populations, such as older adults, are known to have impaired energy intake. In this paper, the relevance of sensory impairments in this older population is described, and the extent to which nutritional and physical activity interventions can modulate these sensory responses when food intake is insufficient is explored. With aging, all senses deteriorate, and in most cases, such deteriorations diminish the nutritional response. The only exception is sight, for which both positive and negative impacts on nutritional response have been reported. From a prevention perspective, nutritional interventions have been understudied, and to date, only hearing is known to be positively affected by a good nutritional profile. In comparison, physical activity has been more frequently studied in this context, and is linked to an improved preservation of 4 senses. Regarding treatment, very few studies have directly targeted sensory training, and the focus of research has tended to be on nutrition and physical activity intervention. Sensory training, and nutritional and physical activity treatments all have beneficial effects on the senses. In the future, researchers should focus on exploring gaps in the literature specifically concerning prevention, treatment, and sensory response to understand how to improve the efficacy of current approaches. In order to maintain sensory acuity and recover from sensory impairment, the current state of knowledge supports the importance of improving nutritional habits as well as physical activity early on in life. A combined approach, linking a detailed lifestyle profile with the assessment of numerous senses and one or more interventional approaches (nutrition, physical activity, sensory training, etc.), would be required to identify effective strategies to improve the nutritional state of older individuals.

Texture Modification Technologies and Their Opportunities for the Production of Dysphagia Foods: A Review

Dysphagia or swallowing difficulty is a common morbidity experienced by those who have suffered a stroke or those undergone such treatments as head and neck surgeries. Dysphagic patients require special foods that are easier to swallow. Various technologies, including high-pressure processing, high-hydrodynamic pressure processing, pulsed electric field treatment, plasma processing, ultrasound-assisted processing, and irradiation have been applied to modify food texture to make it more suitable for such patients. This review surveys the applications of these technologies for food texture modification of products made of meat, rice, starch, and carbohydrates, as well as fruits and vegetables. The review also attempts to categorize, via the use of such key characteristics as hardness and viscosity, texture-modified foods into various dysphagia diet levels. Current and future trends of dysphagia food production, including the use of three-dimensional food printing to reduce the design and fabrication time, to enhance the sensory characteristics, as well as to create visually attractive foods, are also mentioned.