Viscosity measurements of nectar- and honey-thick liquids: product, liquid, and time comparisons

Getting the consistency right in thickened liquids using Viscgo Sticks: A validation study

BACKGROUND

Dysphagia is a condition whereby a person's ability to swallow, eat and drink is impacted. One strategy to manage dysphagia and aid safe swallowing is the modification of food and drink, including using thickening agents to thicken drinks. Drinks are thickened to levels appropriate to a person's swallowing abilities and the underutilised 'syringe flow test' is currently the recommended method for checking thickness levels. Viscgo Sticks were developed as a practical alternative to the flow test.

METHODS

This is a real-world validation study designed to determine validity and reliability of Viscgo Sticks. Independent researchers and healthcare professionals tested Viscgo Sticks (Viscgo Limited) against the flow test in three levels of thickened drinks. Researchers also conducted tests with different thickening agents and different drink types: water, milk, orange juice and hot tea.

RESULTS

The intra- and inter-rater reliability of Viscgo Sticks was moderate to almost perfect (κ = 0.45-0.98) within and between researchers and substantial (κ = 0.66-0.67) within and between healthcare professionals. When tested by researchers and healthcare professionals against the flow test, Viscgo Sticks correctly classified 83.33%-100% of thickened drinks with high accuracy (area under curve = 0.70-1.00).

CONCLUSIONS

A simple and reliable tool like Viscgo Sticks, which can verify a prescribed thickness level of liquid, is invaluable in healthcare settings where day-to-day drink preparation occurs. Overall, Viscgo Sticks provide a reliable and valid means to test thickened drinks in clinical practice with a few exceptions identified.

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.

A Thickening Agent Using Dioscorea japonica Powder Exhibits Suitable Properties for People with Dysphagia

In an aging society, the novel concept of added food functionality in a dysphagia diet is necessary for preventing diseases and maintain nutrition intake. The present study evaluated the utilization of Dioscorea japonica as a thickened liquid for people with dysphagia due to its unique physical properties and beneficial effects on chronic inflammation. The viscosity of the prepared thickened liquid using freeze-dried Dioscorea japonica powder was compared with those of xanthan gum and commercially available thickened liquids in selected conditions resembling to cooking. Dioscorea japonica powder showed high versatility, because the viscosity of its thickened liquid could be easily adjusted by modifying its blending amount and temperature. The thickened liquid of Dioscorea japonica had the most stable viscosity among the thickened liquids when NaCl was added and exhibited excellent resistance to α-amylase, similar to that of the other thickened liquids. The viscosity of the thickened liquid of Dioscorea japonica was relatively stable on changing the pH, but it was slightly unstable when the temperature changed. Overall, the thickened liquid of Dioscorea japonica powder has excellent viscosity stability, comparable to or better than commercially available thickened liquids, and is expected to be used as a new thickened liquid with added food functionality.

Quantitative Textural and Rheological Data on Different Levels of Texture-Modified Food and Thickened Liquids Classified Using the International Dysphagia Diet Standardisation Initiative (IDDSI) Guideline

Diet modification is a common compensation strategy to promote swallowing safety in patients with swallowing difficulties. The International Dysphagia Diet Standardisation Initiative (IDDSI) guideline provides qualitative descriptions on texture-modified food and thickened liquid. This study aimed to establish quantitative textural and rheological data on different IDDSI levels based on common Chinese ingredients and dishes. Textural and rheological properties of 226 samples of various food textures and 93 samples of various liquid consistencies were obtained using a texture profile analysis (TPA) and viscometer, respectively. The establishment of such quantitative data can be used for future texture-modified food product development and research purposes.

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.

Effects of Extraction and Evaporation Methods on Physico-Chemical, Functional, and Nutritional Properties of Syrups from Barhi Dates (Phoenix dactylifera L.)

Date fruits (Phoenix dactylifera L.) are rich in sugar and also contain a substantial amount of phenolic compounds. Therefore, date fruits can be used to produce an alternative sweetener, having lower glycemic index than sucrose. This study investigated the effects of extraction and evaporation methods on various properties of the syrups prepared from Barhi dates. Extraction of date juice with the aid of pectinase or cellulase significantly enhanced the production yield, total phenolic content, and antioxidant activities determined by Ferric Reducing Antioxidant Power and Oxygen Radical Absorbance Capacity assays. Syrups prepared without enzyme application had about 6–7 times higher apparent viscosity than those prepared from the enzyme-assisted extracted juices. Vacuum evaporation produced syrups with significantly lighter color and inferior antioxidant properties than open heating. Properties of date syrups prepared with or without enzyme-assisted extraction followed by open heat evaporation were not different. They had a glucose-to-fructose ratio close to 1:1, received good sensory acceptability scores of above 6 on a 9-point hedonic scale, contained a safe level (<40 mg/kg) of 5-hydroxymethyl-2-furfuraldehyde, and exhibited similar glass transition and melting temperatures; while a greater inhibition on α-amylase activity was observed in syrups obtained from enzyme-assisted extraction. The in vivo glycemic measurement revealed that the syrup prepared with the aid of Pectinex and open heating was classified as low glycemic index (GI = 55) and medium glycemic load (GL = 11). Thus, enzyme-assisted extraction of date juice using Pectinex could be used to produce a healthy natural sweetener from low quality date fruits.

The Pathway from Anatomy and Physiology to Diagnosis: A Developmental Perspective on Swallowing and Dysphagia

Dysphagia results from diverse and distinct etiologies. The pathway from anatomy and physiology to clinical diagnosis is complex and hierarchical. Our approach in this paper is to show the linkages from the underlying anatomy and physiology to the clinical presentation. In particular, the terms performance, function, behavior, and physiology are often used interchangeably, which we argue is an obstacle to clear discussion of mechanism of pathophysiology. We use examples from pediatric populations to highlight the importance of understanding anatomy and physiology to inform clinical practice. We first discuss the importance of understanding anatomy in the context of physiology and performance. We then use preterm infants and swallow-breathe coordination as examples to explicate the hierarchical nature of physiology and its impact on performance. We also highlight where the holes in our knowledge lie, with the ultimate endpoint of providing a framework that could enhance our ability to design interventions to help patients. Clarifying these terms, and the roles they play in the biology of dysphagia will help both the researchers studying the problems as well as the clinicians applying the results of those studies.

Effects of thickened carbonated cola in older patients with dysphagia

Carbonated beverages initiate the swallowing reflex earlier than water and have a shorter pharyngeal transit time. However, the effects of carbonation in thickened beverages of the same flavor on swallowing dynamics have not been reported. Therefore, we investigated the effects of thickened carbonated beverages on swallowing in patients with dysphagia by comparing the swallowing dynamics between thickened carbonated and thickened non-carbonated beverages. We enrolled 38 patients with dysphagia and divided them into two groups. Thickened carbonated and thickened non-carbonated beverages were used. Videoendoscopic swallowing evaluations were performed. Aspiration, penetration, pharyngeal residue, and initiation position of the swallowing reflex were evaluated. The reduction in the amount of residue in both the vallecula (p = 0.007) and pyriform sinus (p = 0.004) was greater after ingestion of thickened carbonated cola than thickened non-carbonated cola. The onset of the swallowing reflex was significantly earlier after ingestion of thickened carbonated cola than thickened non-carbonated cola (p = 0.007). There were no significant differences in the extent of penetration. Thickened carbonated beverages positively affected swallowing compared with thickened non-carbonated beverages. Thus, the use of thickened carbonated beverages may be helpful for patients with dysphagia.

Antibacterial Properties of Honey Nanocomposite Fibrous Meshes

Natural substances are increasingly being developed for use in health-related applications. Honey has attracted significant interest, not only for its physical and chemical properties, but also for its antibacterial activity. For the first time, suspensions of Black Forest honeydew honey and manuka honey UMF 20+ were examined for their antibacterial properties against Escherichia coli and Staphylococcus epidermidis using flow cytometry. The inhibitory effect of honey on bacterial growth was evident at concentrations of 10, 20 and 30 v/v%. The minimum inhibitory effects of both honey types against each bacterium were also investigated and reported. Electrospray ionisation (ESI) mass spectrometry was performed on both Black Forest honeydew honey and manuka honey UMF 20+. Manuka honey had a gluconic concentration of 2519 mg/kg, whilst Black Forest honeydew honey had a concentration of 2195 mg/kg. Manuka honey demonstrated the strongest potency when compared to Black Forest honeydew honey; therefore, it was incorporated into nanofiber scaffolds using pressurised gyration and 10, 20 and 30 v/v% manuka honey-polycaprolactone solutions. Composite fibres were analysed for their morphology and topography using scanning electron microscopy. The average fibre diameter of the manuka honey-polycaprolactone scaffolds was found to range from 437 to 815 nm. The antibacterial activity of the 30 v/v% scaffolds was studied using S. epidermidis. Strong antibacterial activity was observed with a bacterial reduction rate of over 90%. The results show that honey composite fibres formed using pressurised gyration can be considered a natural therapeutic agent for various medicinal purposes, including wound-healing applications.

Evolutionary functional morphology of the proboscis and feeding apparatus of hawk moths (Sphingidae: Lepidoptera)

The morphology of the proboscis and associated feeding organs was studied in several nectar-feeding hawk moths, as well as a specialized honey-feeder and two supposedly nonfeeding species. The proboscis lengths ranged from a few millimeters to more than 200 mm. Despite the variation in proboscis length and feeding strategy, the principle external and internal composition of the galeae, the stipes pump, and the suction pump were similar across all species. The morphology of the smooth and slender proboscis is highly conserved among all lineages of nectar-feeding Sphingidae. Remarkably, they share a typical arrangement of the sensilla at the tip. The number and length of sensilla styloconica are independent from proboscis length. A unique proboscis morphology was found in the honey-feeding species Acherontia atropos. Here, the distinctly pointed apex displays a large subterminal opening of the food canal, and thus characterizes a novel type of piercing proboscis in Lepidoptera. In the probably nonfeeding species, the rudimentary galeae are not interlocked and the apex lacks sensilla styloconica; galeal muscles, however, are present. All studied species demonstrate an identical anatomy of the stipes, and suction pump, regardless of proboscis length and diet. Even supposedly nonfeeding Sphingidae possess all organs of the feeding apparatus, suggesting that their proboscis rudiments might still be functional. The morphometric analyses indicate significant positive correlations between galea lumen volume and stipes muscle volume as well as the volume of the food canal and the muscular volume of the suction pump. Size correlations of these functionally connected organs reflect morphological fine-tuning in the evolution of proboscis length and function.

Flow test by the International Dysphagia Diet Standardization Initiative reveals distinct viscosity parameters of three thickening agents

The International Dysphagia Diet Standardization Initiative (IDDSI) flow test is useful for the global standardization of food consistencies of dysphagia patients. In clinical practice, different compositions of food thickeners are commonly used, directly influencing viscosity parameters and swallowing physiology. We aimed to compare the IDDSI thickness levels, remaining volume in the syringe (RVS), and viscosity parameters of three different food thickeners. As a secondary objective, we compared the cost of preparing 100 mL of thickened drinks using the studied thickeners. Thickeners A (xanthan gum), B (corn starch, tara gum, xanthan gum, and guar gum), and C (corn starch) were prepared in increasing concentrations from 1 to 7 g/100 mL and were assayed in quintuplicate using the IDDSI flow test. Thickeners A, B, and C presented statistically different results for the IDDSI levels, RVS, and viscosity parameters at all concentrations. Thickener A reached higher levels in the IDDSI framework, RVS, and viscosity parameters compared with thickeners B and C. A large range of RVS was observed at different concentrations for thickener B compared with C. Regarding viscosity, thickeners B and C, with corn starch in their composition, showed exponential behavior as concentrations increased, while thickener A presented a linear trend. The thickener composition was significantly influenced by IDDSI classification, RVS, and viscosity parameters. The study shows that xanthan gum thickeners present less variability in IDDSI, RVS, and viscosity compared with starch-based thickeners.

Rheological Properties and Stability of Thickeners for Clinical Use

The adaptation of liquids for patients with dysphagia requires precision and individualization in the viscosities used. We describe the variations of viscosity in water at different concentrations and evolution over time of the three compositions of commercial thickeners that are on the market (starch, starch with gums, and gum). By increasing the concentration in water, the viscosity of gum-based thickeners increases linearly, but it did not reach pudding texture, whereas the viscosity of the starch-based thickeners (alone or mixed with gums) rapidly reaches very thick textures. We modeled the viscosity at different concentrations of the four thickeners using regression analysis (R2 > 0.9). We analyzed viscosity changes after 6 h of preparation. The viscosity of gum-based thickeners increased by a maximum of 6.5% after 6 h of preparation, while starch-based thickeners increased by up to 43%. These findings are important for correct handling and prescription. Gum-based thickeners have a predictable linear behavior with the formula we present, reaching nectar and honey-like textures with less quantity of thickener, and are stable over time. In contrast, starch thickeners have an exponential behavior which is difficult to handle, they reach pudding-like viscosity, and are not stable over time.

[Tasteless thickening agents? A competitive comparison]

Hintergrund

Das Andicken von Flüssigkeiten gehört zu den Standardverfahren der Dysphagietherapie. Diese adaptive Methode soll u. a. einem posterioren Leaking entgegenwirken und die Anforderung an verlangsamte Schutzreflexe durch eine reduzierte Fließgeschwindigkeit des Bolus senken. Bisherige Erhebungen zeigen jedoch aufgrund der Geschmacksperzeption eine ablehnende Haltung von Patienten gegenüber angedickten Flüssigkeiten. Diese Studie untersucht, ob zwischen verschiedenen Andickungsmitteln Geschmacksunterschiede bestehen.

Methoden

An der Studie haben 37 gesunde Probanden Teil genommen und 8 auf dem deutschen Markt erhältliche Andickungsmittel untereinander verglichen. Zur Testung wurden jeweils 2 mit Wasser angerührte Andickungsmittel einander gegenübergestellt. Die Probanden sollten dann entscheiden, welches sie geschmacklich präferierten. Bis zu 7 dieser Paarvergleiche wurden von jedem Probanden vorgenommen. Insgesamt wurden 224 Paarvergleiche durchgeführt. Aus diesen wurde mittels eines probabilistischen Modells eine relative Geschmacksgüte bestimmt und eine Signifikanztestung der Unterschiede durchgeführt.

Ergebnisse und Schlussfolgerung

Zwischen den verschiedenen Andickungsmitteln zeigten sich signifikante Geschmacksunterschiede. Es kann vermutet werden, dass sich die Geschmacksunterschiede auf die Inhaltsstoffe der jeweiligen Andickungsmittel zurückführen lassen. Im therapeutischen Setting sollte für eine höhere Akzeptanz von Kostanpassungen nach Möglichkeit die Ausprobe unterschiedlicher Andickungsmittel erfolgen. Unklar bleibt, ob die hier gezeigten Geschmacksunterschiede sich auch zeigen, wenn anstelle von Wasser andere Flüssigkeiten wie Kaffee, Tee oder Säfte angedickt werden.

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.

Dysphagia thickeners in context of use. Changes in thickened drinks’ viscosity and thixotropy with temperature and time of consumption

Dysphagia patients might need to thicken drinks. The viscosity of these thickened drinks varies among commercial thickeners and drinks compromising the ingesta safety. The aim of this study was to investigate how temperature and resting time affect the rheological properties of thickened drinks. Four commercial thickeners were used to thicken water, coffee, orange juice, and milk at two concentration levels used in dysphagia drinks (nectar and pudding). To study the effect of temperature, flow curves of thickened drinks at 10°C and 50°C were obtained and to study the effect of resting time, flow curves of thickened drinks at 25°C were obtained at different times (0, 30, and 60 min). All samples displayed shear‐thinning and time‐dependent behavior (thixotropy or antithixotropy). The effect of temperature on viscosity values and relative thixotropic area (RTA) depended on the thickener and the drink. Overall, apparent viscosity showed higher values at 50°C than 10°C, especially in thickeners containing starch and in drinks with higher soluble solids (milk and orange juice). This was attributed to the water absorption of pregelatinized starch granules favored by temperature. Antithixotropy was mainly observed at pudding concentration for the starch‐containing thickeners, and decreased with temperature. The effect of resting time on apparent viscosity and RTA depended also on the drink and thickener. Mostly, apparent viscosity values increased with resting time and antithixotropic behavior decreased. Both effects, increase in viscosity and decrease of antithixotropy with time, indicated that thickening action was being developed over the resting time.

Sensory Profiling and External Preference Mapping of Pre-Thickened Water Products for Dysphagia

Dysphagia is a dysfunction of the swallowing system and thickened beverages are widely prescribed as a treatment. The objective of this study was to determine the sensory characteristics of pre-thickened water products and determine sensory drivers of liking for those types of products. Pre-thickened water products (two starch-based and two gum-based) were tested in both nectar and honey thick versions. Based on product availability, one product was neutral water, and the others were water with lemon flavoring added. The sensory characteristics of the products were evaluated with a highly trained descriptive panel, and the viscosity of the products was evaluated with both the Bostwick consistometer and the line spread test. Previously published consumer data was used to determine preference maps with the descriptive data. All lemon-flavored products had similar flavor characteristics, except the Thick & Easy Clear that had a less lemon-related flavor than the others. After excluding the lemon-related flavor characteristics, all pre-thickened products had similar “base flavor” notes, no matter whether the products were starch-based or gum-based. This contrasts with literature, which reports differences in flavor of thickened beverages prepared using thickening agents. The thickness of the products varied between nectar and honey thickness, but also varied among products that were stated to be at the same level of thickness. External preference mapping showed that both lemon-related flavor and a thinner beverage texture are potential drivers of consumers acceptance of the product, which was expected based on other studies. In conclusion, pre-thickened beverages are good alternatives for self-mixed thickening agents but a standard for thickness should be agreed on and used by manufacturers.

Psyllium (Plantago ovata Forsk) in frozen banana pulp: Influence on rheological, nutritional and sensory characteristics

A frozen banana pulp with functional properties was developed and characterized in this work. For this, 0 g, 3 g, 5 g and 7 g of psyllium in 100 g of banana pulp were added. The use of this fiber in industrialized products can contribute to the nutritional enrichment of the products and provide functional benefits already acknowledged, such as lowering LDL cholesterol, lowering blood glucose, increasing satiety and relieving constipation. According to the World Health Organization, vegetable consumption should be increased, as it reduces the risk of chronic diseases. The main purpose of this work was to incorporate psyllium in frozen banana pulp to develop a healthy product. The samples were evaluated through chemical analyses, rheological properties and sensory testing with Check-All-That-Apply questions (CATA). The addition of psyllium had a significant effect not only on the viscosity but also on the sensory and nutritional properties of the frozen banana pulp. This study indicated that the production of frozen banana pulp with psyllium is viable, as it has desirable nutritional and sensory characteristics which can contribute to the maintenance of health.

Effects of the internal syringe shape on the International Dysphagia Diet Standardization Initiative flow test

The International Dysphagia Diet Standardization Initiative (IDDSI) proposed the flow test (FT) as a simple method for measuring the viscosity of thickened liquids. However, the FT specifies the use of a particular syringe type (BD-Slip), which is unfortunately not easily available in Japan. Therefore, the current study primarily aimed to investigate the effects of the internal syringe shape on IDDSI FT and identify the most suitable syringe available in Japan for xanthan gum-based thickened liquids. Accordingly, four syringes, namely, Luer slip tip, Luer-Lok tip, TERUMO, and NIPRO syringes, were used to examine FT value with water and nine different water viscosity levels. The correlation and systematic errors on residual FT values between the BD-Slip syringe and the other three syringes were analyzed. The two-dimensional internal shapes of the four syringes were measured using industrial computed tomography (CT) scanning. Based on the results of our FT, TERUMO had the smallest error range among the three syringes, without systematic errors. On a CT scan, three of five tip-shape parameters showed the smallest difference between BD-Slip and TERUMO syringe. Therefore, TERUMO had the smallest FT error range compared with that in BD-Slip tip syringe, indicating that TERUMO could be used as a substitute for BD-Slip when performing IDDSI FT with xanthan gum-based thickened water in Japan.

Thickened Formulas Used for Infants with Dysphagia: Influence of Time and Temperature

Infant dysphagia is commonly managed using thickened formulas. Substantial research investigates thickening of a variety of beverages for adults and children, yet few studies address the unique considerations of thickened formula for infants. Understanding the consistency and behaviour of thickened formula will guide clinicians and parents to make informed decisions to minimise risk of aspiration. To investigate the effect of time and storage temperature on the flow properties of thickened formula, four formulas and two thickeners currently utilised at a major metropolitan children's hospital in Australia were tested in combinations, at refrigerated and room temperatures. Their flow properties were measured at three time-points (baseline, 1 h, 24 h) using the International Dysphagia Diet Standardisation Initiative (IDDSI) Flow Test, the current clinical standard for classifying drinks based on flow properties. A combination of paired t tests, Wilcoxon Signed-Rank tests, repeated measures analysis of variance (ANOVA) and Cohen's d was used to statistically compare flow properties and determine the significance of the observed data. At baseline, 98% (n = 48) of the thickened formula bottles were measured as thinner than the "mildly thick" IDDSI category to which they were prepared. Conversely, at 24 h, 17% were measured thicker than "mildly thick" whilst 10% measured too thin for the category "mildly thick". Refrigerated samples increased in thickness more significantly over time compared to those stored at room temperature. Two of the formulas, when thickened, resulted in a foamy mixture non-compatible with IDDSI Flow Test measurement. As a result, these two formulas were not subjected to further testing. All the tested commercial products behaved differently to each other and were unstable over varying times and temperatures. This finding indicates the need for improved guidelines regarding preparation and storage of thickened fluids. Further investigation is recommended into the chemical processes underlying the observed deviations.

Combining Liquid Oral Drugs with Thickener: Compatibility and Changes in Viscosity

Older adults with oropharyngeal dysphagia (OD) are unable to swallow pills safely, so some of them use liquid-formulated drugs mixed with thickeners to ensure safety. The aim of this study was to analyze the physical compatibility of a group of drugs with a thickener formulated with modified starch (Thick & Easy®). A secondary goal was to evaluate the amount of thickener needed to obtain the thickness levels 2, 3, and 4 defined by IDDSI framework for each drug. For this purpose, the rheological properties of the mixtures obtained were determined. Samples of each drug were prepared and 7, 10, and 12 g of thickener were added. Physical compatibility of the mixtures was observed; the apparent viscosity of the samples was measured using a rotational viscometer, and the results obtained were compared with the reference drug-free sample. We analyzed 45 medicinal products (38 active substances). Three drugs (almagate, ibuprofen, and macrogol) were found to be physically incompatible with the thickener and should not be mixed. Viscosity measurements indicated that clarithromycin and plantago ovata increased the viscosity of the mixture and required lower amount to achieve the target textures (110 cP, 590 cP, and 2620 cP for 7 g, 10 g, and 12 g in drug-free samples, respectively), whereas another subset reduced viscosity and required more thickener. This proved very relevant for acetylcysteine, amoxicillin, calcifediol, ferrous gluconate, fosfomycin, lactitol, lactulose, mepifiline, paracetamol, rivastigmine, sertraline, and tramadol. Measurements were below 1750 cP. Awareness of how each drug behaves when combined with thickeners is essential to avoid potential complications in OD.

How Accurate Are the Consistency Labels Used in Hong Kong? An Objective Study of the Consistency of Thickened Liquids Using International Dysphagia Diet Standardisation Initiative and Consistometric Measurements

OBJECTIVES

The present study objectively examined the consistency (thickness) of labels that are used in Hong Kong for the population with dysphagia using an International Dysphagia Diet Standardisation Initiative (IDDSI) flow test and Bostwick consistometric measurements.

METHODS

Liquids were prepared by thickening water to achieve 4 consistency labels (slightly thick, mildly thick, medium thick, and extra thick) according to manufacturer's instructions, employing 2 types of thickening products that are used in Hong Kong, i.e., starch based and gum based. For each consistency label prepared using each thickening product, the IDDSI flow test and consistometric measurements were obtained and compared.

RESULTS

The results showed that the actual thickness of liquids was highly dependent on the type of thickener (starch based vs. gum based) used. Thickened liquids prepared using the starch-based thickener were generally thinner than the actual value at a lower concentration.

CONCLUSION

Though prepared strictly following the manufacturer's instructions, the thickened liquids fail to faithfully correlate with the standardized norms established according to the IDDSI framework and the objective consistometric measurement using a Bostwick consistometer. Therefore, caution must be exercised when administering a thickened diet following the manufacturer's instructions for patients with dysphagia.

Assessment of tomato-based thick fluid diet for patients with dysphagia using a simple and cheap test

Swallowing difficulty, also known as dysphagia, is a health condition that can be managed by different approaches, such as changing the viscosity of fluid foods with thickener agents. Tomato-based beverages such as "gazpacho" and "salmorejo" are common foods much appreciated by the populations that adopt a Mediterranean diet, mainly in Spain. These beverages usually present a low viscosity, challenging to include in diets for dysphagia patients. Thus, this work aimed at evaluating the flow properties of tomato-based beverages with or without the addition of thickener agents (based on maltodextrin or gum) using a simple and cheap method proposed by the International Dysphagia Diet Standardization Initiative (IDDSI) to verify the suitability of using those products in a diet of patients with dysphagia. The study also evaluated the differences in using BD-type syringes on the test. Results indicated that the type of thickener significantly (p < .05) affects the samples' flow properties, enhancing their rheological behavior. The type of syringe can also affect the results, as they present different Luer slip tips. The results revealed that tomato-based beverages may have their properties improved simply by using low amounts of thickener agents (1.2-3.0 g 200 ml^-1 ) and that the IDDSI test can be an alternative, cheap and straightforward method for evaluating these types of foods in hospital environments. Including tomato-based beverages in the diet of patients with dysphagia may present many benefits as these products have a rich nutritional composition (fiber) in addition to biocompounds such as lycopene and phenolic compounds.

Thickened Liquids Using Pureed Foods for Children with Dysphagia: IDDSI and Rheology Measurements

Children with dysphagia, or swallowing disorder, are at an increased risk for developing respiratory compromise, failure to thrive, and aversion. Thickened liquids can be recommended for children with dysphagia, if shown to be effective on instrumental examination and if strategies/interventions with thin liquids are not successful. Thickened liquids have many benefits, including creating a more cohesive bolus, slowing oropharyngeal transit time, and reducing aspiration. However, preparing thickened liquids with commercially available thickeners can result in poor compliance due to concerns regarding taste, texture, accessibility, cost, thickness variability, and potential negative impact of these substances on a child's immature digestive tract. The purpose of this study was to determine if liquids could be successfully thickened with widely available, commercial pureed foods, and to assess how these mixtures compare to starch and gum based thickening agents. The International Dysphagia Diet Standardisation Initiative (IDDSI) flow test was performed for each sample of puree thickened liquids, gum based thickened water, and cornstarch based thickened water. In addition, rheology testing was performed on each category of the samples to measure viscosity at various shear rates and temperatures, and to assess the presence of yield stress. Results revealed that liquids thickened with smooth textured purees were comparable to commercial starch and gum based thickeners, and may be offered as a viable alternative.

Effect of commercially available thickening agents on ready-to-feed infant formulas

Because of the importance of providing the appropriate fluid consistency for effective management of swallowing problems (dysphagia) in infants, this project sought to determine the effect of three commercially available thickening agents on the resulting thickened consistencies of commonly prescribed, ready-to-feed infant formulas. Nine ready-to-feed infant formulas were thickened with three different thickening agents to nectar and honey consistencies following manufacturer's instructions and their resulting thickness was measured via line spread test (LST). The nine formulas with nothing added to them (thin liquids) and the 27 target-nectar and 27 target-honey samples together created 63 unique samples for comparison. A series of one-way analysis of variance analyses were conducted to determine if the resulting thickness (as measured by LST values) for target categories of nectar and honey consistencies was significantly influenced by the type of thickening agent used. The achieved thickness of the formula samples as measured by LST values was statistically significantly different for the three different types of thickening agents used to achieve a target nectar consistency, F (2, 24) = 15.55, p < .001, η p 2 = .709. Additionally, the achieved thickness of the formula samples was statistically significantly different for the three different types of thickening agents used to achieve a target honey consistency, F (2, 24) = 16.18, p < .001, η p 2 = .709. The results of this study reveal that the choice of thickening agent impacts the resulting thickness of ready-to-feed infant formula.

Creating psychometric scales for perceptual assessment of fruit juices' refreshing and thickness attributes

Persons look for beverages to satisfy thirst (refresh) and feel fulfilled (thick). However, refreshing and thickness are concepts that lack a measurement instrument that captures an accurate judgment of consumers' perceptions. This research aims to propose a tool to assess consumers' refreshing and thickness expectations of fruit juices. Items were developed through a two-stage qualitative-exploratory study, followed by a quantitative study describing the scale's composition using an Item Response Theory approach. Hence, we suggest a set of items to consider when measuring both concepts from a perception task. Moreover, results show that thickness and refreshing are distinct and independent ideas. We provide a theoretical contribution defining each construct and recognizing the attributes that best describe refreshing and thickness for five different fruit juices. Our methodological contribution is creating a scale for each of the concepts. Practically, developing a thickness and refreshing scale is useful for product developers and marketers who expect to satisfy consumers' needs for soft drinks.

Effect of mixing method on resulting thickness of infant formula

Previous research shows that factors such as time, temperature, nutritional make-up of a liquid, and type of thickening agent can significantly alter the resulting thickness of liquids. This study sought to determine the effect of three distinct mixing methods on the resulting thickness of ready to feed infant formulas mixed to Mildly and Moderately Thick (International Dysphagia Diet Standardization Initiative [IDDSI] Levels 2 and 3) with three different thickening agents. Eight commercially available infant formulas were mixed with three different thickening agents by three different mixing methods. The IDDSI Syringe Flow Test was used to categorize the thickened formulas. Chi square analyses were completed to determine the impact of mixing method on the thickened formulas. The majority (94%) of thickened formula combinations prepared to a target Mildly Thick consistency produced thickened formula that was thinner or thicker than the target. In contrast, the majority (76%) of thickened formula combinations prepared to a target Moderately Thick (IDDSI Level 3) consistency produced thickened formula that was equivalent to the target consistency. A statistically significant relationship was found between mixing methods and resulting IDDSI category for samples mixed to a target of Moderately Thick. The thickening agent and method of mixing must be considered carefully when preparing infant formulas to Mildly and Moderately Thick target IDDSI categories. Based on results of this study, it is recommended that providers utilize a clinical testing method, such as the IDDSI Syringe Flow Test, when attempting to create a Mildly Thick formula consistency.

Application of a Manufacturer's Guideline and an IDDSI-Driven Guideline to Thickening of Some Non-water Beverages: A Rheological Study

This study aimed to evaluate an existing liquid-thickening guideline provided by a major manufacturer of thickener in Hong Kong and to provide directions for the implementation of the IDDSI framework. Fifteen participants who are naïve to liquid thickening were required to prepare thickened liquids samples from three drink bases (i.e., Milk-tea, Chinese tea, and Herbal tea) at two target consistency levels (i.e., mildly and medium/moderately thick) based on two guidelines (i.e., the manufacturer's guideline and an IDDSI-driven guideline). Viscosities of the samples were measured rheologically to reflect liquid consistency. The manufacturer's guideline resulted in distinguishable viscosities at the two consistency levels (F(1, 35.464) = 113.764, p < 0.001, η_p² = 0.802), as well as different viscosities in different drink bases (F(1.267, 35.464 = 92.951, p < 0.001, η_p² = 0.769). Comparison between the manufacturer's and the IDDSI-driven guideline showed that the later resulted in more viscous liquid samples in all drink bases and at both consistency levels. The difference between the two guidelines was statistically significant (F(1,28) = 35.137, p < 0.001, η_p² = 0.557). Following only the manufacturer's guideline when thickening non-water beverages may lead to discrepancy between the resultant and prescribed consistencies. Thus, it should be considered inadequate to ensure swallowing safety. The effect of drink base should be emphasized to patients and caregivers, and pre-serving tests should be introduced. Despite similar classifications and terminologies used between the current local framework and the IDDSI framework, measures should be taken to avoid potential confusions and associated threats to swallowing safety.

Energetic supplementation for maintenance or development of Apis mellifera L. colonies

Background

The nutritional requirements of honeybees (Apis mellifera) for their complete development need to be supplied through food sources available in the environment, since honeybees are insects that depend directly on blossoming food sources. However, at certain times a food-supply reduction can promote nutritional stress, thus necessitating food supplementation for maintenance or production stimulus of the colonies. Thus, the determination of optimal energy supplementation can assist in the maintenance and production of colonies.

Methods

Twenty Apis mellifera beehives were used (with five beehives per treatment): CTL, control (without feeding); SJ, sugarcane juice; SS, sugar syrup; and IS, inverted sucrose. We evaluated the food consumption, population development, and physiological state (expression of vitellogenin and hexamerin 70a genes) of each colony.

Results

The results showed that the supplementation of colonies with sugar syrup resulted in an intermediate consumption level (894.6 ± 291 mL) and better development (384.9 ± 237.3 and 158.3 ± 171.6 cm², sealed and open brood, respectively). Furthermore, this diet ensured that the colonies were in a good physiological state, as bees fed this diet presented the highest relative expression levels of vitellogenin and hexamerin 70a among all the diets tested.

Conclusions

Therefore, sugar syrup is concluded to be the best artificial energetic food for use in the supplementation of honeybee colonies.

Consistencies and terminologies - the use of the International Dysphagia Diet Standardization Initiative

Introduction

Introduction: this study aimed to verify the ability of speech therapists to identify, sort and name the different consistencies used in neurogenic oropharyngeal dysphagia (NOD) management, and to compare the results with the terms proposed by the International Dysphagia Diet Standardization Initiative (IDDSI). Methods: this research was approved by the ethics committee. Sixty speech therapists who work with NOD patients sorted 5 commercial foods from thinnest to thickest to match IDDSI levels 0 to 4, and then used a term to designate each consistency. Results: most subjects (76.66%) sorted the foods properly. Terminologies were divergent at all levels. For level 0, practitioners assigned 3 different terms. For level 1, 24 different terms were reported; for level 2 there were 25 terms, 23 terms for level 3, and 18 terms for level 4. Level 0 (IDDSI - thin) was designated by most participants as liquid; level 1 (IDDSI - slightly thick) was referred to as semi-thickened liquid; level 2 (IDDSI - mildly thick) as thickened liquid; level 3 (IDDSI - moderately thick) as honey; and level 4 (IDDSI - extremely thick) as pasty by most subjects. A reduced number of participants used terms in accordance with IDDSI. Level 0 was appropriately named by 5 subjects (8.33%); levels 1, 2 and 4 by 2 practitioners each (3.33%); and level 3 by 1 professional (1.66%). None of the subjects named all 5 IDDSI levels correctly. Conclusion: most practitioners progressed consistencies properly. There was a diversity of terminologies used for the same consistency at all levels, with no standardization.

Nutrition Care Management Practices for In-Patients with Dysphagia in Korean Clinical Settings

This study aimed to examine nutrition care management for in-patients with dysphagia and to evaluate knowledge on nutrition care related to dysphagia among dietitians in clinical settings. A total of 554 questionnaires were distributed to dietitians at hospitals located in Seoul and Gyeonggi Province in Korea, and 147 responses were used for data analysis after excluding responses with significant missing data. Study participants worked at general hospitals (37.2%), long-term care hospitals (24.3%), hospitals (19.2%), and tertiary hospitals (11.5%). Prior education and training related to dysphagia was received by 69.9% of the respondents. The percentage of hospitals that had diet guidelines for dysphagia was 68.0%. Dysphagia diets of 2 levels and 3 levels were provided in 55.1% and 34.7% of the hospitals, respectively. Overall 74.7% of the dietitians responded that they provided information on dysphagia diets to in-patients and caregivers, but only 45.7% of dietitians did so in the long-term care hospitals. Among the respondents who used commercial thickening agents, 77.2% used only one type of commercial thickening agent. Patients or caregivers (75.7%) or nurses (34.5%) were reported to modify viscosity of liquid. Dietitians showed low levels of knowledge on nutrition care related to dysphagia (a mean of 5.14 based on possible scores from 0 to 10 points). To promote nutritional consumption and prevent malnutrition and aspiration, hospitals need the standardized diet guidelines, and dietitians should improve their expertise in nutritional care for patients with dysphagia.

The Importance of Extensional Rheology in Bolus Control during Swallowing

Thickened fluids are commonly used in the medical management of individuals who suffer swallowing difficulty (known as dysphagia). Previous studies have shown that the rheological properties of a liquid affect the flow behavior of the bolus in swallowing, such as pharyngeal transit time. While there is no doubt that shear rheology is a highly important factor for bolus flow, it is suspected that extensional properties of a liquid bolus also plays an important role in swallowing, due to elongation of the bolus as it flows through the oropharynx. Our aim in this work was to observe the effect of extensional viscosity on pharyngeal transit time and elongation of the bolus during swallowing. Eight samples of thickened liquid barium that were shear-controlled, but varied in extensional viscosity and two samples that were extensional-controlled, but varied in shear viscosity were swallowed by eight healthy individuals. Data were collected under lateral view of videofluoroscopy swallow study (VFSS); measures of pharyngeal transit time and the ratio of the length to the width of the bolus on the frame of Upper Esophageal Sphincter (UES) opening were taken from the VFSS recordings. It was observed that the pharyngeal transit time generally increases when the fluids are thickened to higher IDDSI consistency. Additionally, higher extensional viscosity fluids reduced the elongation of the bolus during swallowing, thus potentially reducing the risk of post-swallow residue due to bolus breakage. This study confirmed the relevance of the extensional viscosity of the bolus in swallowing.

The impact of modification techniques on the rheological properties of dysphagia foods and liquids

Modifying food and the textures of food has been done for decades within the food science and technology field. More recently, modifying the texture of foods has been used to manage swallowing disabilities (dysphagia). Swallowing disabilities are often associated with dehydration and malnutrition, thus nutritional intervention has formed part of serving texture-modified diets. The question remains whether these modification techniques are viable for individuals with swallowing disabilities living in majority world countries. This study used two modification methods on a widely used specialized nutritious food (SNF) to determine whether it may be modified and used in dysphagia management. The techniques had to be ergonomic and economically appropriate for individuals with swallowing disabilities living in majority world countries. The International Dysphagia Diet Standardization Initiative's (IDDSI) standards were used to determine whether the texturally modified SNF is safe for swallowing. Rheological measurements were performed to determine apparent viscosity and structure recovery of each sample. The effects of two modification techniques, aeration and particle separation, on the rheological properties of the SNF were also measured and analyzed. It was determined that both milk and water could be used with this SNF to create a dysphagia diet, but only under certain conditions. The overall results indicated that heating the samples increased the apparent viscosity and exacerbated lumping. Room temperature samples had less lumps and could be classified to the desired levels of the IDDSI (Level 2 and Level 4). Using a whisk to aerate the samples reduced lumps significantly and using a sieve to separate particles of liquid samples eliminated lumps. This study provides new data on how texture modification techniques and the IDDSI framework could be adapted to individuals living in majority world countries. By using modification techniques that are ergonomic and economically viable and an SNF with longevity, this study could be useful in guiding future training of nursing staff and caregivers of individuals living in poverty or resource-constrained communities. This study also adds to the data on the rheological properties of dysphagia foods, although this study did not make use of commercial thickeners generally used in the modification of diets.

The Relationship between Texture-Modified Diets, Mealtime Duration, and Dysphagia Risk in Long-Term Care

Many long-term care (LTC) residents have an increased risk for dysphagia and receive texture-modified diets. Dysphagia has been shown to be associated with longer mealtime duration, and the use of texture-modified diets has been associated with reduced nutritional intake. The current study aimed to determine if the degree of diet modification affected mealtime duration and to examine the correlation between texture-modified diets and dysphagia risk. Data were collected from 639 LTC residents, aged 62-102 years. Nine meal observations per resident provided measures of meal duration, consistencies consumed, coughing and choking, and assistance provided. Dysphagia risk was determined by identifying residents who coughed/choked at meals, were prescribed thickened fluids, and/or failed a formal screening protocol. Degree of texture modification was derived using the International Dysphagia Diet Standardization Initiative Functional Diet Scale. There was a significant association between degree of diet modification and dysphagia risk (P < 0.001). However, there was no association between diet modifications and mealtime duration, even when the provision of physical assistance was considered. Some residents who presented with signs of swallowing difficulties were not prescribed a texture-modified diet. Swallowing screening should be performed routinely in LTC to monitor swallowing status and appropriateness of diet prescription. Physical assistance during meals should be increased.

Evaluation of Thickened Fluids Used in Dysphagia Management Using Extensional Rheology

Recent studies show that understanding the rheological properties of thickened fluids, such as viscosity and yield stress, is advantageous in designing optimal thickened fluids for the treatment of dysphagia. To date, these studies have focused on the rheological behavior of thickened fluids in shear deformation, while limited information is available on the surface tension of thickened fluids or their rheological behavior in extensional deformation. Knowledge of the extensional properties of thickened fluids (extensional viscosity and cohesiveness) is important to fully understand the behavior of such fluids while swallowing. Our aim in this work, therefore, was to characterize water and skim milk thickened with a commercial thickener (xanthan gum based) to determine extensional deformation and surface tension properties. It was observed that the surface tension decreases as the thickener concentration increases due to the accumulation of the biopolymer at the surface of the fluid when it dissolves in water. In addition, the extensional viscosity of the fluid increased over time as the filament thinned (i.e., as the Hencky strain increased) until it reached a plateau. It was observed that the maximum extensional viscosity, which is related to the cohesiveness of the fluid, increases with the higher concentrations of thickener. However, the cohesiveness of thickened skim milk was lower than that of the thickened water at a given thickener concentration due to lower surface tension. This study confirms that by increasing the concentration of thickener, it will not only increase the shear viscosity (i.e., bolus thickness) of the fluid, but also the extensional viscosity (i.e., bolus cohesiveness).

Incremental Adjustments to Amount of Thickening Agent in Beverages: Implications for Clinical Practitioners Who Oversee Nutrition Care Involving Thickened Liquids

This study examined the changes in viscosity in response to small alterations in the amount of a thickening agent mixed with three commonly thickened beverages. A total of 11 incremental adjustments in the amount of a starch-based thickening agent (5.0 g to 7.0 g) were made. The results showed that the incremental increases resulted in systematic changes to the liquid thickness, reflecting modifications that ranged from a nectar (mildly thick) to a honey-like (moderately thick) level of consistency. The findings emphasize the importance of the proper preparation of thickened beverages, highlighting the need for standards in training practices and the use of simple measurement tools for assuring the prescribed levels of consistency.

Abdominal pumping involvement in the liquid feeding of honeybee

Honeybee drinking is facilitated by a "mop-like" tongue, which helps honeybees suck in the sucrose solution from the environment. However, the liquid-transport mechanism from the pharynx to the crop, especially the natural link between abdominal pumping and dipping behavior on the sucrose solution intake, remains obscure. A significant increase in abdominal pumping frequency is observed when honeybees drink the sucrose solution. Abdominal pumping exhibits a function other than respiration. This second function assists in driving the sucrose solution from the pharynx to the crop. We combine the experimental measurements using high-speed video and X-ray phase contrast imaging with theoretical modeling to investigate the effect of abdominal pumping in liquid feeding of honeybee. Experimental results show that a honeybee performs abdominal pumping in the abdomen at a faster rhythm during sucrose solution feeding than during other physiological activities. In addition, the period of abdominal pumping is in concordance with that of dipping cycles. Theoretical analysis demonstrates that the abdomen, which is comparable with a micro pump, changes its volume rhythmically. Such expansion reduces pressure in the abdomen, which also reduces pressure in the crop and helps propel the sucrose solution from the pharynx to the crop. Abdominal pumping can help honeybees improve their feeding efficiency and save foraging time. This research work reveals a specific feeding mechanism of insects fed on sucrose solution and opens a new way for the design of microfluidic pump.

Modifying the consistency of food and fluids for swallowing difficulties in dementia

BACKGROUND

People with dementia can have feeding and swallowing difficulties (dysphagia). Modification of the consistency of food or fluids, or both, is a common management strategy. However, diet modification can affect quality of life and may lead to dehydration and malnutrition. Evidence on the benefits and risks of modifying food and fluids is mandatory to improve the care of people with dementia and dysphagia.

OBJECTIVES

To determine the effectiveness and adverse effects associated with modifying the consistency of food and fluids in improving oral intake and eliminating aspiration in adults with dysphagia and dementia.

SEARCH METHODS

We searched ALOIS (the Specialised Register of the Cochrane Dementia and Cognitive Improvement Group), the Cochrane Library, MEDLINE via Ovid SP, Embase via Ovid SP, PsycINFO via Ovid SP, CINAHL via EBSCOhost, LILACS via BIREME, ClinicalTrials.gov and the World Health Organization (WHO) Portal on 9 May 2018. We also checked the reference lists of relevant articles to identify any additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs and cluster-RCTs published in any language that measured any of the outcomes of interest. We included trials with adults with a clinical diagnosis of dementia with symptoms and signs of dysphagia confirmed on instrumental assessment. We included participants with all types, stages and severities of dementia. Control groups received either no intervention or interventions not involving diet modification or modification to sensory properties of food.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed for inclusion all potential studies identified. Data were extracted independently along with assessment of methodological quality using standard Cochrane methods. We contacted study authors for additional unpublished information.

MAIN RESULTS

No trials on modification of food met the inclusion criteria. We included two studies that examined modification to fluids. Both were part of the same large multicentre trial and included people with dementia and people with or without dementia and Parkinson's disease. Participation in the second trial was determined by results from the first trial. With unpublished data supplied by study authors, we examined data from participants with dementia only. The first study, a cross-over trial, investigated the immediate effects on aspiration of two viscosities of liquids (nectar thick and honey thick) compared to regular liquids in 351 participants with dementia using videofluoroscopy. Regular liquids with a chin down head posture, as well as regular liquids without any intervention were also compared. The sequence of interventions during videofluoroscopy may have influenced response to intervention. The second study, a parallel designed RCT, compared the effect of nectar and honey thick liquids with a chin down head posture over a three-month period in a subgroup of 260 participants with dementia. Outcomes were pneumonia and adverse intervention effects. Honey thick liquids, which are more consistent with descriptors for 'spoon thick' or 'extremely thick' liquids, showed a more positive impact on immediate elimination of aspiration during videofluoroscopy, but this consistency showed more adverse effects in the second follow-up study. During the second three-month follow-up trial, there were a greater number of incidents of pneumonia in participants receiving honey thick liquids than those receiving nectar thick liquids or taking regular liquids with a chin down posture. There were no deaths classified as 'definitely related' to the type of fluids prescribed. Neither trial addressed quality of life. Risk of bias for both studies is high. The overall quality of evidence for outcomes in this review is low.

AUTHORS' CONCLUSIONS

We are uncertain about the immediate and long-term effects of modifying the consistency of fluid for swallowing difficulties in dementia as too few studies have been completed. There may be differences in outcomes depending on the grade of thickness of fluids and the sequence of interventions trialled in videofluoroscopy for people with dementia. Clinicians should be aware that while thickening fluids may have an immediate positive effect on swallowing, the long-term impact of thickened fluids on the health of the person with dementia should be considered. Further high-quality clinical trials are required.

The effect of administration media on palatability and ease of swallowing of multiparticulate formulations

Multiparticulate formulations based on pellets, granules or beads, could be advantageous for paediatrics, geriatrics and patients with swallowing difficulties. However, these formulations may require suitable administration media to facilitate administration. The aim of this work was to investigate the effect of administration media properties on palatability and ease of swallowing of multiparticulates. A range of vehicles were developed using xanthan gum (XG) and carboxymethyl cellulose (CMC) as model hydrocolloids. Such vehicles were prepared at three consistency levels (Level 1 - 'syrup', Level 2 - 'custard' and Level 3 - 'pudding') to investigate the effect of viscosity on their performance as administration media. A randomised, single-blind sensory evaluation study was carried out in thirty healthy adult volunteers using microcrystalline cellulose pellets as model multiparticulates, dispersed in the hydrogels (and water as control) at a concentration of 250 mg in 5 ml. Samples were evaluated using 5-point scales. The use of hydrogels as administration media improved a range of sample attributes compared to water formulations, including appearance, taste, mouthfeel, ease of swallowing and residue in the mouth (all improved by ca. 0,5 points) and oral grittiness perception (improved by ca. 1 point). Polymeric hydrogels thickened to medium consistency (Level 2, XG 0.5% and CMC 1.0% w/v) demonstrated the best performance.