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| Representation of Viscosity as a constant relating an applied shear stress to the resulting shear velocity.
Source publication
Dysphagia is a swallowing disorder characterized by the difficulty in transferring solid foods and/or liquids from the oral cavity to the stomach, imparing autonomous, and safe oral feeding. The main problems deriving from dysphagia are tracheo-bronchial aspiration, aspiration pneumonia, malnutrition and dehydration. In order to overcome dysphagia-...
Context in source publication
Context 1
... can be defined as the resistance of a fluid to flow and is due to the intramolecular cohesion forces that attract molecules together and to the exchange of moments between molecules. More specifically, we can consider a fluid between two large parallel plates, one of which is boundary and the other is moving with a velocity v in the x direction. The fluid can be regarded as made of infinitesimal layers (Figure 1). The layer closer to the moving plate will move in the x direction at a velocity almost equal to v, conversely the layer next to the stationary plate will move very slowly. Considering a fluid with a very large number of layers, the sliding among layers generates a velocity gradient that it is called shear. The relationship between the frictional force f applied to a surface of area A and velocity gradient dv/dx was stated by Newton and is summarized ...
Citations
... Test methods introduced by IDDSI framework (spoon and fork pressure test) are defined based on a scientific basis targeted for individuals and nursing uses and maybe the simplest methods but inappropriate for industrial applications, because there are no measuring units defined by IDDSI. Texture Profile Analysis (TPA) which is based on simulation of two first bites on food could provide more detailed textural parameters including hardness, cohesiveness, adhesiveness, springiness, gumminess, and chewiness (Sukkar et al., 2018). With these parameters, the safety criteria of the textural properties of foods could be defined (Dufresne and Germain, 2004). ...
... The mixing of saliva with the puree and the mechanical manipulation of the puree in the mouth resulted in the formation of a food bolus. The presence of saliva has been suggested to increase cohesion and viscoelastic properties of the bolus due to the human mucin components secreted in food-stimulated saliva [21]. Nevertheless, a higher cohesiveness value obtained from instrumental measurements means that an increase in the applied force is required for the puree processing in the mouth to facilitate the mixing of the puree with the saliva to form a bolus prior to swallowing. ...
The creation of 3D printed food with programmed texture has the ambition of getting personalized properties through novel texture perceptions with many different ingredients and is helping the swallowing or mastication problems of vulnerable people. This study is done to determine the correlation between the instrumental and sensory evaluation of 3D-printed protein-fortified puree potatoes. At the moment there are not many studies about this correlation, and this information can be very helpful for food texture development. For people with swallowing difficulties, it is critical to have access to safe food with the desired texture. Therefore, understanding the correlation between texture-modified food will aid in the formulation of safe foods with desired sensory properties. Instrumental measurements of fortified puree were performed by a texture analyzer and the attributes obtained were firmness, consistency, cohesiveness, and index of viscosity. Quantitative descriptive analysis with eight trained panelists was employed to characterize the texture of the the3D-printed protein-fortified puree based on six sensory attributes: firmness, thickness, smoothness, rate of breakdown, adhesive, and difficulty swallowing. Three proteins (soy, cricket, and egg albumin with two different concentrations of 3 and 5%) were evaluated against puree potato without any protein as a control. The correlation results obtained from texture analysis and sensory evaluation were statistically significant (P < 0.05) which can be used to understand the impact of ingredients on textured modified puree to predict the sensory attributes which need a lot of time for training panelists.
... Amylase catalyzes the hydrolysis of α-1,4 glycosidic linkages between glucose units in starch, resulting in amylose and amylopectin breakdown. (Sukkar et al., 2018;Souza, 2010). Hence, the stability of thickener to carbohydrate-hydrolyzing enzymes should be taken into consideration in food preparation for dysphagia patients (Sukkar et al., 2018). ...
... (Sukkar et al., 2018;Souza, 2010). Hence, the stability of thickener to carbohydrate-hydrolyzing enzymes should be taken into consideration in food preparation for dysphagia patients (Sukkar et al., 2018). ...
The aim of this paper was to investigate effects of inulin and ultrasonic homogenization on particle size distribution and microstructure of oil-in-water emulsion gels stabilized by psyllium husk were investigated. The emulsion gel was assessed their utility in meat puree prepared for people with dysphagia. The results showed that increasing inulin percentage resulted in reduced particle size and improved emulsion stability with the optimum at 20% w/w inclusion. Ultrasonic homogenization further enhanced the emulsion stability by reducing the size of emulsion droplet and improving encapsulation of emulsion droplet. Increasing inulin concentrations in the emulsion gels added into purees also corresponded with decreasing total expressible fluid (TEF). The stability of puree against the action of carbohydrate-hydrolyzing enzymes (α-amylase and α-glucosidase) was improved with the addition of emulsion gels. Therefore, these developed emulsion gels could be beneficial in formulating modified-texture food prepare for people with dysphagia.
... Dysphagia is classified according to location and evidence of drug delivery failure due to mechanical or inflammatory processes (103). Once dysphagia occurs, the incidence of malnutrition in patients is often greatly increased. ...
Objective
Dysphagia has become one of the important factors that cause malnutrition in the whole age group. At present, tube feeding is still the mainstream means to solve the problem of dysphagia. However, tube feeding has physical and mental harm to people, and the ways of non-tube feeding are relatively diversified. The significance of the thickening mechanism described in some articles to solve the problem of dysphagia is not clear.
Setting and participants
All patients with dysphagia worldwide, including oropharyngeal dysphagia (OD) and non-oropharyngeal dysphagia.
Methods
We searched the literature in Pubmed, Web of Science and Cochrane Library and initially browsed the titles and abstracts. We reviewed the full text of the articles that met our topic, and the language of the article was limited to English.
Results
We found that food thickening to a certain degree (350–1,750 cP) can reduce the complications of choking, aspiration, reflux, and other complications in patients with dysphagia, and reduce the social disorder, anxiety, and other psychological problems caused by catheterization and surgery. Significantly, food science engineers should invite clinicians to intervene in the development of specialty foods from different perspectives such as clinical pathophysiology and fluid mechanics.
Conclusion and implications
It is necessary to develop special foods for patients with dysphagia, which requires scientists from different disciplines to work together.
... Texture modification of dysphagia diets with thickening powders has been regarded as the most common practice for dysphagia management. In particular, water and other liquid foods that are normally consumed on a daily basis, such as fruit juices, milk, tea or coffee etc., are necessarily modified to control their bolus to flow at moderate velocity through the pharyngeal stage as one cohesive and uniform bolus in order to mitigate the risk of aspiration (Clavé et al., 2004;Sukkar et al., 2018). ...
Thickening powders are regularly used in various drinks for the effective management of dysphagia and for the improved quality of life of these patients. Rheology of these thickened liquids can change significantly depending on the dispersing media that may lead to some adverse effects. Therefore, the effects of dispersing media, i.e., water, apple juice and low-fat milk, on shear and extensional rheology of thickened liquids prepared with xanthan gum or guar gum-based thickening powders were investigated in this study. Shear rheological results revealed a power law concentration dependence of the relative zero shear viscosity (ηr,0∝cn) for both thickening powders in all dispersing media, i.e., n = 3.41–4.26 for xanthan gum-based and n = 4.55–5.42 for guar gum-based. For a given thickening powder concentration, the zero shear viscosity was mainly affected by the dispersing media, whereas there was no marked effect on high shear viscosity, especially at shear rate 50 s⁻¹ that is a characteristic value traditionally assumed for oral processing. The flow behaviour of all samples could be described effectively by the modified Carreau-Yasuda model, thus, making it more convenient to compare the material parameters among different samples. Additionally, these dispersing media showed drastic effect on extensional rheological characteristics of the thickened samples, particularly on the filament life span and extensional viscosity. For xanthan gum-based powder, the values of both parameters were decreased at least 2-fold when dissolved in apple juice or milk, signifying weakening extensional property of these thickened beverages compared to thickened water. However, for guar gum-based thickener, enhanced extensional properties were obtained when dissolved in milk, whereas partial hydrolysis may occur in apple juice, leading to inferior extensional property compared to that of water. These differences are largely ascribed to molecular characteristics of the active polysaccharides in these thickening powders. Overall, these results provide new insights into the shear and extensional rheology of food thickeners in various dispersing media that can be used to assist in treating individual patients with dysphagia.
... Interestingly, the EAT-10, Kuchi-Kara and ODS-PP tools mention subjective measures about dysphagia, namely the desire to eat or going out for meals, which seems to be an important component of clinical evaluation, as dysphagia significantly influences the patient's quality of life [41]. In fact, recent studies have highlighted how dysphagia greatly impacts quality of life [42,43], namely highlighting that rehabilitation and treatment should focus on the pharyngeal phase of dysphagia. ...
Oropharyngeal Dysphagia (OD) significantly decreases a patient’s quality of life and poses a high economic burden to institutions. In this sense, evaluation and assessment are important interventions for health professionals, although current tools and instruments are multiple and are dispersed in the literature. The aim of this review was to map existing screening tools to assess and evaluate OD in adult patients, identify their relevant clinical parameters and respective contexts of use and provide a systematic approach and summary to better inform practice. A scoping review was developed guided by the JBI methodology and using PRISMA-ScR to report results published between 2014 and 2021, in English, Spanish and Portuguese. Databases included Medline, Academic Search Complete, CINAHL Complete, Scielo, Google Scholar, ScienceDirect, OpenGrey and B-On. Mendeley was used to store and screen data. A total of 33 studies were included in the study, of which 19 tools were identified, some being intervention-based tools and others an algorithm for decision. The most common context used was in the general population and older adults. Regarding clinical parameters, the most common were food consistency, presence of the cough reflex, swallowing effort, voice changes and weight. As oropharyngeal dysphagia concerns important risks for the patient, a rigorous assessment must be performed. In this sense, the review identified specific disease-related tools and more general instruments, and it is an important contribution to more efficient dysphagia screening and prevention.
... Por outro lado, considerar somente a modificação na viscosidade dos alimentos no tratamento dietético da disfagia pode ocasionar a redução da ingestão alimentar devido à menor aceitação sensorial desses alimentos pelos pacientes (SUKKAR et al., 2018). ...
... Although several authors describe texture modified foods and drinks as an important management strategy for patients with OD [22][23][24][25][26], several others have stressed lack of strong evidence to support the importance of texture modified foods and liquids for the management of OD [27][28][29][30][31][32][33][34][35][36].Thus, fluids that are too thick are usually unpalatable and are often rejected by patients [11,32,37,38]. In this regard, several potential hazards and disadvantages of texture modified diets for OD management have been reported, such as poor hydration [39][40][41][42][43], poor nutrition [44][45][46][47], delayed medication absorption [40,48], impact on quality of life [49][50][51][52][53], care giver perceptions [54], and increased costs associated with treatment [55][56][57][58][59][60]. ...
... However, it is affected by the degree of saliva stimulation (i.e. mechanical; chemical) [24], as well as by the age, sex and medical condition of the person. ...
There is an increasing proof of the relevance of rheology on the design of fluids for the diagnosis and management of dysphagia. In this sense, different authors have reported clinical evidence that support the conclusion that an increase in bolus viscosity reduces the risks of airway penetration during swallowing. However, this clinical evidence has not been associated yet to the definition of objective viscosity levels that may help to predict a safe swallowing process. In addition, more recent reports highlight the potential contribution of bolus extensional viscosity, as elongational flows also develops during the swallowing process. Based on this background, the aim of this review paper is to introduce the lecturer (experts in Dysphagia) into the relevance of Rheology for the diagnosis and management of oropharyngeal dysphagia (OD). In this sense, this paper starts with the definition of some basic concepts on Rheology, complemented by a more extended vision on the concepts of shear viscosity and elongational viscosity. This is followed by a short overview of shear and elongational rheometrical techniques relevant for the characterization of dysphagia-oriented fluids, and, finally, an in-depth analysis of the current knowledge concerning the role of shear and elongational viscosities in the diagnosis and management of OD (shear and elongational behaviors of different categories of dysphagia-oriented products and contrast fluids for dysphagia assessment, as well as the relevance of saliva influence on bolus rheological behavior during the swallowing process).
... In the last few years, various studies have demonstrated that for optimal modification of the food texture it is necessary to know not only the viscosity, but also other important parameters such as bolus viscoelasticity, yield stress, propulsion pressure, extensional viscosity, mechanical properties and the degree of lubrication of dysphagia foods [10,13,15,17,[27][28][29][30]. Therefore, various fundamental testing methods can be performed to obtain all these parameters. ...
Dysphagia is a medical condition that affects normal swallowing. To prevent the risk of aspiration or choking, thickened fluids and texture-modified foods have been used for dysphagia management with the goal of slowing down the flow of liquids and protecting the airway. This article summarizes the available information about the rheological and textural parameters, the characterization of the most-used thickeners and the application of alternative texture modification technologies that are crucial to developing safe dishes for people who suffer from swallowing difficulties. Regarding rheological and textural measurements, fundamental and empirical methods are described.
... A deglutição é um processo complexo que envolve estruturas relacionadas com a cavidade oral, faringe, laringe e do esôfago, submetidos a um controle neuromuscular que permite o transporte do bolo alimentar da boca até o estômago, sem permitir a entrada de qualquer substância para a via aérea (Ertekin & Aydogdu, 2003). A dificuldade ou incapacidade de mastigar ou engolir alimentos ou líquidos devido ao enfraquecimento dos músculos usados para engolir é chamada de disfagia (Sukkar et al., 2018). ...
Dysphagia is characterized by a dysfunction in the swallowing process, which impairs safe and autonomous oral feeding. To minimize the negative effects, modified texture foods and thickened drinks are used. This study aimed to compare the viscosities of commercial food thickeners when dissolved in liquid preparations. Three starch-based thickeners were used to thicken five preparations (water, orange juice, milk, thickened milk, and coffee). Nutritional information, microscopy, pH, swelling power, and solubility of the granules and the viscosity of the preparations as a function of time and temperature were evaluated. All thickeners had a high percentage of carbohydrates, sodium, and the presence of modified starch. The thickeners promoted changes in the pH of the preparations and the presence of modified corn starch showed an increase in solubility and swelling power. About temperature variations, lower values increased viscosity, and viscosity increased with rest, probably due to the continuous hydration of the thickening agent. The greater the consistency you want to achieve, the greater quantities of product need to be added. The thickened food preparations showed different viscosities, depending on the food matrix, temperature, time and the amount of product added.
