The Swallowing Characteristics of Thickeners, Jellies and Yoghurt Observed Using an In Vitro Model

Abstract

Drinks and foods may be thickened to improve swallowing safety for dysphagia patients, but the resultant consistencies are not always palatable. Characterising alternative appetising foods is an important task. The study aims to characterise the in vitro swallowing behaviour of specifically formulated thickened dysphagia fluids containing xanthan gum and/or starch with standard jellies and yoghurt using a validated mechanical model, the "Cambridge Throat". Observing from the side, the model throat can follow an experimental oral transit time (in vitro-OTT) and a bolus length (BL) at the juncture of the pharynx and larynx, to assess the velocity and cohesion of bolus flow. Our results showed that higher thickener concentration produced longer in vitro-OTT and shorter BL. At high concentration (spoon-thick), fluids thickened with starch-based thickener showed significantly longer in vitro-OTT than when xanthan gum-based thickener was used (84.5 s ± 34.5 s and 5.5 s ± 1.6 s, respectively, p < 0.05). In contrast, at low concentration (nectar-like), fluids containing xanthan gum-based thickener demonstrated shorter BL than those of starch-based thickener (6.4 mm ± 0.5 mm and 8.2 mm ± 0.8 mm, respectively, p < 0.05). The jellies and yoghurt had comparable in vitro-OTT and BL to thickeners at high concentrations (honey-like and spoon-thick), indicating similar swallowing characteristics. The in vitro results showed correlation with published in vivo data though the limitations of applying the in vitro swallowing test for dysphagia studies were noted. These findings contribute useful information for designing new thickening agents and selecting alternative and palatable safe-to-swallow foods.

Beverage Type and Hydration Parameters in Older Persons Following a Texture-Modified Diet and Living in Long-term Care Residences

“…On the other side, avoured gelatine is not a liquid state per se; and it breaks down when chewing, as well as melting when it is in contact with the mouth or at temperatures above 25 ºC. These characteristics can bring functional problems since some authors suggest that avoured gelatines might increase oropharyngeal residue; although, in vitro swallowing behaviour of jellies and yogurt showed comparable characteristics to thickened uids [26].…”

Easy to Swallow “Instant” Jelly Formulations for Sustained Release Gliclazide Delivery

“…25e28 Detailed descriptions of the use of the in vitro model for testing jellies were reported by Patel et al 2019. 16 In brief, the test sample (5 mL) was held within a 25 mm wide dialysis tube attached to the curved top of the model. Jelly 1 (free-standing jelly) was manually fragmented into 4 mm pieces before putting into the sample tube.…”

“…The in vitro-oral transit time (OTT) and bolus length (BL) of the test sample at area of the model representing the pharynx and larynx juncture were calculated from the images. 16 In vitro-OTT was calculated as the time taken by the roller to reach an angle of 120 as reported by Mowlavi et al, 2016. 27 ImageJ (Fiji) image processing software was used to calculate BL by capturing the first image in which the bolus front reached the pharynx and larynx juncture.…”

“…BL was measured as the length of the bolus from front to tail. 16 Evaluation of "Instant" Jellies as Delivery Vehicle for Sustained Release Gliclazide Microparticles…”

“…14,15 Both hard and granular jellies have demonstrated flow properties that can contribute to safe swallowing by patients with dysphagia, indicating their suitability as medication aids for these patients. 16 Recent formulation developments also included commercial technologies which convert solid dosage forms such as tablets and pellets into semi-solid, gellike dosage forms by adding water to aid swallowing. 17,18 Gliclazide is a sulfonylurea for the treatment of Type 2 diabetes.…”