Food polysaccharides and roles of rheology and tribology in rational design of thickened liquids for oropharyngeal dysphagia: A review

Effects of dispersing media on the rheological and tribological properties of basil seed mucilage-based thickened liquids

The development of thickening powders for the management of dysphagia is imperative due to the rapid growth of aging population and prevalence of the dysphagia. One promising thickening agent that can be used to formulate dysphagia diets is basil seed mucilage (BSM). This work investigates the effects of dispersing media, including water, milk, skim milk, and apple juice, on the rheological and tribological properties of the BSM-thickened liquids. Shear rheology results revealed that the thickening ability of BSM in these media in ascending order is milk < skim milk ≈ apple juice < water. On the other hand, extensional rheology demonstrated that the longest filament breakup time was observed when BSM was dissolved in milk, followed by skim milk, water, and apple juice. Furthermore, tribological measurements showed varying lubrication behavior, depending on the BSM concentration and dispersing media. Dissolution of BSM in apple juice resulted in the most superior lubrication property compared with that in other dispersing media. Overall, this study provides insights on BSM's application as a novel gum-based thickening powder in a range of beverages and emphasizes how important it is for consumers to have clear guidance for the use of BSM in dysphagia management.

Rheological characterization of chia seed gum as a thickening agent used for dysphagia management

Dysphagia has emerged as a serious health issue facing contemporary society. Consuming thickened liquids is an effective approach for improving the swallowing safety for dysphagia patients. The thickening effect of chia seed gum (CSG), a novel thickener, in different dispersing media (water, orange juice, and skim milk) was investigated. Moreover, the potential application of CSG for dysphagia management was evaluated by comparison with xanthan gum (XG) and guar gum (GG). The thickened liquids prepared with 0.4 %-1.2 % (w/v) CSG, XG, and GG could be classified into levels 1-4, 2-4, and 1-3, respectively, according to the International Dysphagia Diet Standardization Initiative (IDDSI) framework. All the thickened liquids displayed shear-thinning characteristics that facilitated safe swallowing. The viscosities (η50) of CSG dissolved in water (0.202-1.027 Pa·s) were significantly greater than those of CSG dissolved in orange juice (0.070-0.690 Pa·s) and skim milk (0.081-0.739 Pa·s), indicating that CSG had a greater thickening effect in water than in orange juice and skim milk. Compared with those prepared with GG, the thickened liquids prepared with CSG and XG exhibited greater viscoelasticity, better water-holding capacity, and more compact networks. The findings suggested that CSG can be used as a potential thickener for thickening liquid foods to manage dysphagia.

Development of soy protein isolate gels added with Tremella polysaccharides and psyllium husk powder as 3D printing inks for people with dysphagia

The aim of this study was to investigate the feasibility of soy protein isolate (SPI) gels added with Tremella polysaccharides (TPs) and psyllium husk powder (PHP) as 3D printing inks for developing dysphagia-friendly food and elucidate the potential mechanism of TPs and PHP in enhancing the printing and swallowing performance of SPI gels. The results indicated that the SPI gels with a TP : PHP ratio of 3 : 7 could be effectively used as printing inks to manufacture dysphagia-friendly food. The addition of TPs increased the free water content, resulting in a decrease in the viscosity of the SPI gels, which, in turn, reduced the line width of the 3D-printed product and structural strength of the gel system. The addition of PHP increased disulfide bond interactions and excluded volume interactions, which determined the mechanical strength of SPI gels and increased the line width of the printed product. The synergistic effects between TPs and PHP improved the printing precision and structural stability. This study presents meaningful insights for the utilization of 3D printing in the creation of dysphagia-friendly food using protein-polysaccharide complexes.

Pathways in formulating foods for the elderly

The growth of the elderly population worldwide is posing significant challenges to human society. The progressive physical and physiological changes occur with aging, including decreased appetite, incomplete digestion, and reduced absorption of nutrients. A common feature of many elderly people's diets is a deficiency in proteins (especially easily digestible ones) and micronutrients (e.g., vitamins, zinc, iron, and calcium). One of the solutions to this problem is the incorporation of these components into suitably texture-modified foods. There is a dearth of products that meet the needs of the elderly with special medical/health conditions such as dysphagia, osteoporosis, diabetes, and cardiovascular disease, as well as those who are in hospital and palliative care. Future research and development of foods for the elderly must address specific dietary needs of different subgroups of elderly people with underlying health conditions. The existence of different physical and physiological stages of the elderly means that their specific dietary requirements must be considered. This review summarizes current knowledge on nutritional requirements including those with underlying health problems and outlines the research and innovation pathways for developing new foods considering nutrition, texture, flavor, and other sensory aspects.

Exploration of green preparation strategy for Lycium barbarum polysaccharide targeting Bacteroides proliferative and immune-enhancing activities and its potential use in geriatric foods

Lycium barbarum polysaccharide (LBP) is beneficial for elderly people, but its use is limited in geriatric foods due to the lack of comprehensive information on its preparation strategy and physical property. In this study, the low-ester rhamnogalacturonan-I (RG-I) type pectic polysaccharide-protein complexes with varying physicochemical properties, structural characteristics, proliferative activities on Bacteroides, and immune-enhancing activities on RAW 264.7 cells, were obtained by moderate-temperature acid extraction within adjustment of enzymatic and physical pretreatments. LBP prepared by moderate-temperature acid extraction, namely S1-A, showed the strongest immune-enhancing activity via increasing the phagocytosis capacity and NO release of RAW 264.7 cells by 23 % and 76 %, respectively. S1-A exhibited relatively high viscosity and calcium ion response characteristic with the application potential for thickened liquid foods for the elderly with dysphagia. LBP prepared by composite cellulase and pectinase pretreatment combined with moderate-temperature acid extraction, namely S1-M1, showed the strongest Bacteroides proliferative activity that was equivalent to 0.60-0.97 times of that of inulin. S1-M1 exhibited extremely low viscosity and strong tolerance to food nutrients with high processing applicability for fluid foods. This study provided crucial data for the preparation and application of LBP targeting gut microbiota disorders and immunosenescence for the development of geriatric foods.

Polysaccharide-dextrin thickened fluids for individuals with dysphagia: recent advances in flow behaviors and swallowing assessment methods

The global aging population has brought about a pressing health concern: dysphagia. To effectively address this issue, we must develop specialized diets, such as thickened fluids made with polysaccharide-dextrin (e.g., water, milk, juices, and soups), which are crucial for managing swallowing-related problems like aspiration and choking for people with dysphagia. Understanding the flow behaviors of these thickened fluids is paramount, and it enables us to establish methods for evaluating their suitability for individuals with dysphagia. This review focuses on the shear and extensional flow properties (e.g., viscosity, yield stress, and viscoelasticity) and tribology (e.g., coefficient of friction) of polysaccharide-dextrin-based thickened fluids and highlights how dextrin inclusion influences fluid flow behaviors considering molecular interactions and chain dynamics. The flow behaviors can be integrated into the development of diverse evaluation methods that assess aspects such as flow velocity, risk of aspiration, and remaining fluid volume. In this context, the key in-vivo (e.g., clinical examination and animal model), in-vitro (e.g., the Cambridge Throat), and in-silico (e.g., Hamiltonian moving particles semi-implicit) evaluation methods are summarized. In addition, we explore the potential for establishing realistic assessment methods to evaluate the swallowing performance of thickened fluids, offering promising prospects for the future.

Food Processing and Nutrition Strategies for Improving the Health of Elderly People with Dysphagia: A Review of Recent Developments

Dysphagia, or swallowing difficulty, is a common morbidity affecting 10% to 33% of the elderly population. Individuals with dysphagia can experience appetite, reduction, weight loss, and malnutrition as well as even aspiration, dehydration, and long-term healthcare issues. However, current therapies to treat dysphagia can routinely cause discomfort and pain to patients. To prevent these risks, a non-traumatic and effective treatment of diet modification for safe chewing and swallowing is urgently needed for the elderly. This review mainly summarizes the chewing and swallowing changes in the elderly, as well as important risk factors and potential consequences of dysphagia. In addition, three texture-modified food processing strategies to prepare special foods for the aged, as well as the current statuses and future trends of such foods, are discussed. Nonthermal food technologies, gelation, and 3D printing techniques have been developed to prepare soft, moist, and palatable texture-modified foods for chewing and swallowing safety in elderly individuals. In addition, flavor enhancement and nutrition enrichment are also considered to compensate for the loss of sensory experience and nutrients. Given the trend of population aging, multidisciplinary cooperation for dysphagia management should be a top priority.

Effects of Calcium and pH on Rheological Thermal Resistance of Composite Xanthan Gum and High-Methoxyl Apple Pectin Matrices Featuring Dysphagia-Friendly Consistency

High-methoxyl apple pectin (AP) derived from apple was employed as the main ingredient facilitating rheological modification features in developing dysphagia-friendly fluidized alimentary matrices. Xanthan gum (XG) was also included as a composite counterpart to modify the viscoelastic properties of the thickened system under different thermal processes. The results indicate that AP is extremely sensitive to thermal processing, and the viscosity is greatly depleted under a neutral pH level. Moreover, the inclusion of calcium ions echoed the modification effect on the rheological properties of AP, and both the elastic property and viscosity value were promoted after thermal processing. The modification effect of viscoelastic properties (G' and G″) was observed whne XG was incorporated into the composite formula. Increasing the XG ratio from 7:3 to 6:4 (AP:XG) triggers the rheological transformation from a liquid-like form to a solid-like state, and the viscosity value shows that the AP-XG composite system exhibits better thermal stability after thermal processing. The ambient modifiers of pH (pH < 4) and calcium chloride concentration (7.5%) with an optimal AP-XG ratio of 7:3 led to weak-gel-like behavior (G″ < G'), helping to maintain the texture properties of dysphagia-friendly features similar to those prior to the thermal processing.

Effects of barium sulfate on rheological properties and IDDSI flow consistency of liquid stimuli prepared using commercial thickening powders

During videofluoroscopic swallowing study (VFSS), barium sulfate (BaSO4 ) is commonly added into food samples as a radiopaque contrast media for bolus visualization and examination. Accordingly, the consistency and flow behavior of barium stimuli can differ significantly from their non-barium counterparts. Such differences may have a subsequent impact on the validity of VFSS. Therefore, in this study, effects of barium sulfate on the shear and extensional rheological properties and IDDSI (International Dysphagia Diet Standardization Initiative) flow consistency of liquids prepared using various commercial thickening powders were investigated. Results showed that all barium stimuli exhibited shear thinning behavior but with significantly higher shear viscosity compared to the non-barium counterparts. A shift factor of viscosity at shear rate 50 s-1 with values in range of 1.21-1.73 could be used to describe the increase in the viscosity for samples thickened with gum-based thickeners. However, the change in the viscosity was not invariant for the stimuli prepared starch-based thickener. The addition of BaSO4 had a negative impact on extensional properties of samples by demonstrating a faster filament rupture. The extent of impact on the decrease in filament breakup time was more pronounced in xanthan > guar gum ≈ tara gum-based thickeners. Based on the IDDSI flow test, no significant effect of BaSO4 was found on the gum-based thickeners, whereas there was a marked effect in the starch-based sample. These results can be used beneficially to assist clinicians in the dysphagia diagnosis for matching rheological properties of the barium stimuli to enhance effectiveness dysphagia interventions.

The Provision of Texture-Modified Foods in Long-term Care Facilities by Health Professionals: Protocol for a Scoping Review

BACKGROUND

Malnutrition among older adults with dysphagia is common. Texture-modified foods (TMFs) are an essential part of dysphagia management. In long-term care (LTC) facilities, health professionals have implemented TMFs, but their application has not been fully elucidated, making them heterogeneous.

OBJECTIVE

We aim to explore the implementation of TMFs in LTC facilities, particularly focusing on the role of health professionals in nutritional care involving TMFs (eg, deciding the type of food, preparing and giving the food, and evaluating the outcomes).

METHODS

A scoping review using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodological approach will be performed. A comprehensive search for published literature will be systematically performed in PubMed, CINAHL, MEDLINE, ProQuest, PsycINFO, and Science Citation Index (Web of Science). Data screening and extraction will be performed by 2 reviewers independently. The studies included will be synthesized, summarized, and reported, following the preferred reporting items of the Mixed Methods Appraisal Tool. Our review will consider the following study designs: mixed methods, quantitative, and qualitative. Studies with patients who are not older adults will be excluded.

RESULTS

Data extraction will be completed by February 2023. Data presentation and analyses will be completed by April 2023, and the final outcomes will be completed by June 2023. The study findings will be published in a peer-reviewed journal.

CONCLUSIONS

Our scoping review will consider studies related to TMF interventions for older adults in LTC residential facilities, with no exclusion restrictions based on country, gender, or comorbidities. Studies on interventions that address TMF-related issues, such as deciding the type of food, preparing and giving the food, and evaluating the outcomes, are qualified for inclusion.

TRIAL REGISTRATION

OSF Registries 79AFZ; https://osf.io/79afz.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/44201.

Effect of Hogweed Pectin on Rheological, Mechanical, and Sensory Properties of Apple Pectin Hydrogel

This study aims to develop hydrogels from apple pectin (AP) and hogweed pectin (HP) in multiple ratios (4:0; 3:1; 2:2; 1:3; and 0:4) using ionotropic gelling with calcium gluconate. Rheological and textural analyses, electromyography, a sensory analysis, and the digestibility of the hydrogels were determined. Increasing the HP content in the mixed hydrogel increased its strength. The Young’s modulus and tangent after flow point values were higher for mixed hydrogels than for pure AP and HP hydrogels, suggesting a synergistic effect. The HP hydrogel increased the chewing duration, number of chews, and masticatory muscle activity. Pectin hydrogels received the same likeness scores and differed only in regard to perceived hardness and brittleness. The galacturonic acid was found predominantly in the incubation medium after the digestion of the pure AP hydrogel in simulated intestinal (SIF) and colonic (SCF) fluids. Galacturonic acid was slightly released from HP-containing hydrogels during chewing and treatment with simulated gastric fluid (SGF) and SIF, as well as in significant amounts during SCF treatment. Thus, new food hydrogels with new rheological, textural, and sensory properties can be obtained from a mixture of two low-methyl-esterified pectins (LMPs) with different structures.

Yoghurt as a deglutition aid for oral medication: effects on famotidine powder dissolution rate and pharmacokinetics

Deglutition aid foods are used to help patients with dysphagia take oral medications. Yoghurt is occasionally used to help swallow medications; however, its influence on pharmacokinetics is poorly understood. Yoghurt made with Lactococcus cremoris subsp. cremoris FC has a characteristic viscous texture that facilitates bolus formation and deglutition due to its metabolite exopolysaccharide. We assessed yoghurt prepared with L. cremoris FC as a food deglutition aid. We performed a dissolution test using famotidine powder mixed with yoghurt and a food thickener. Famotidine dissolution rates without deglutition-assisting foods and with yoghurt or food thickener were 102.3 ± 1.7, 85.7 ± 4.6, and 46.4 ± 1.1% after 15 min, respectively. Next, we orally administered famotidine powder with water, yoghurt, and food thickener to rats and measured plasma famotidine levels. We observed no significant differences between all test groups. The T_max of famotidine mixed with a food thickener was significantly lower than that with yoghurt. These results suggest that yoghurt with L. cremoris FC did not remarkably affect the dissolution and pharmacokinetic profiles of famotidine powder. Thus, the administration of famotidine with yoghurt might be a suitable alternative to powder administration as a deglutition aid for patients.

Review of the effect of amylase-resistant dysphagia products on swallowing safety

PURPOSE OF REVIEW

Thickened fluids are a widely utilised compensatory management strategy for people with impaired swallowing (dysphagia). Over recent years there has been a shift in practice to offer gum-based instead of starch-based products. A key marketing message has been that gum-based thickeners with amylase-resistant properties are superior in promoting 'safer swallowing'. This review sought evidence to evaluate the effect of amylase-resistant products on swallowing safety.

RECENT FINDINGS

No studies directly compared the effect of amylase-resistant products with usual care or products without amylase resistance. Five studies cited amylase-resistant properties and compared gum-based to starch-based dysphagia products or thin fluids. Swallowing safety was frequently judged subjectively with rating scales. Swallowing biomechanics were not included and clinically meaningful outcomes, such as incidence of aspiration pneumonia, were not reported. A scoping review of the grey literature found little evidence that amylase-resistant properties of dysphagia products were of significant concern to clinicians or patients.

SUMMARY

Despite references to the 'importance' of amylase-resistant properties of dysphagia products there is no evidence that this property improves swallowing safety. Further research is needed using objective and clinically meaningful outcome measures to allow clinicians and patients to make informed decisions for dysphagia management.

Food for the elderly based on sensory perception: A review

Background

The impairments of physiological functions caused by aging are common problems in the elderly, especially the impairments of sensory perception. Besides, close relationship between food sensory perception and nutritional status also suggests the importance of dietary management for the elderly population. The foods taking sensory perception into account are urgently needed by the elderly.

Scope and approach

This review analyzed sensory perception changes and their effects on food behaviors and nutritional status. Besides, sensory properties essential for aged-foods and acquisition methods, as well as current status of such foods were summarized.

Key findings and conclusions

Soft, smooth and moisty foods were more suitable for the elderly with chewing and swallowing dysfunction, which can be prepared by gelation, enzyme treatment, blade tenderization and other non-thermal technologies. Flavor enhancement/enrichment, irritant addition and packet sauces were recommended to compensate the impairment of chemical sensory. Molds, piping bag and 3D printing were suggested for refining appearance of pureed foods, and improving appetite of the elderly.

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Sensory perception changes of the elderly affect food behaviors and health.

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Soft, smooth, and moisty foods are more suitable for the elderly.

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Gelation and enzyme treatment are applied to modify the texture of aged food.

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Packet sauces may meet the heterogenetic flavor requirements of the elderly.

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Visually attractive food made by 3D printing can increase the appetite of elderly.