Time‐Dependent Rheological Behavior of Starch‐Based Thickeners and Herb Infusion Dispersions for Dysphagia Management

Abstract

The causes of dysphagia include neurological conditions and cancer. Swallowing impairment of liquids represents a risk of aspiration, pneumonia, dehydration, and nutritional deficiencies. Commercial thickeners often based on modified cornstarch address this issue. The herb Matico (Buddleja globosa Hope) is used as a wound‐healing adjuvant treatment for oral mucositis caused by cancer therapies. This study analyzes the flow behavior of Matico infusion with two thickeners, Thick & EasyTM, and Enterex® Food Thickener at three concentrations. A rheological assessment is performed (20 ± 1 °C subsequent intervals: 1–100 s−1, constant shear step at 100 s−1, and 100–1 s−1, each one with a 120 s span) at five time points (0–60 min). Rheological behavior is adjusted to the Herschel–Bulkley model. Significant differences (p < 0.05) are obtained for yield stress (σ0), consistency coefficient (K), and flow behavior index (n) between time‐points, supporting the increase in apparent viscosity (ηa) during rest. Shear thinning, Bingham plastic, and shear thickening behaviors are obtained for the three concentrations 4.5, 6.75, and 9.0 g 100 mL−1. Besides, a non‐reported rheopectic effect is found at the highest concentration, showing a consistent increase in ηa. These findings reveal the critical effect of time on thickener dispersions that might reduce safety and efficiency during the eating process.

Experimental and Computational Investigation of the IDDSI Flow Test of Liquids Used in Dysphagia Management

“…Rheological models: A Herschel–Bulkley model was applied to the liquids 21,30 using linear regression using Matlab software (Mathworks, Natick, MA).…”

“…Thus two liquids with equal apparent viscosity at one shear rate can have very different viscosity at higher and lower shear rates. 21,26,30,40 Clinically this is important since two types of thickened liquid with the same reported viscosity at one measurement rate may exhibit different clinical outcomes, e.g. being incompletely swallowed.…”

“…11,19,40 Dynamic mechanical analysis (DMA) has also been applied to measure viscous and elastic moduli 4 —texture modified materials have been shown to have a significant elastic component which may relate to their cohesiveness when swallowed. Finally, yield stress has been measured 14,21 and although its absolute magnitude is small, it can be sufficient to support surface texture to a height of a few mm which enables semi-fluid foods to be consumed with a fork or spoon. DMA and yield stress measurements involve stresses and strains many orders of magnitude smaller than those involved in swallowing, 13,33 yet the outcomes have been shown to relate to perception.…”

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

“…Different commercial thickeners can give different drink viscosities, which can cause confusion and lead to incorrect/inconsistent thickened drinks for dysphagia patients if brands are changed. Furthermore, changes in viscosity have been observed when using the same thickener for different drinks, which contributes to the difficulty of controlling the thickened drinks' viscosity (Garin et al, 2014; Martínez, Troncoso, Robert, Quezada, & Zúñiga, 2019; Moret‐Tatay, Rodríguez‐García, Martí‐Bonmatí, Hernando, & Hernández, 2015; Waqas, Wiklund, Altskär, Ekberg, & Stading, 2017).…”