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.