Formulating protein-based beverages for the dysphagia diets of the elderly: viscosity, protein quality, in vitro digestion, and consumers acceptability.

Abstract

Dysphagia is defined as a disorder of the swallowing mechanism. The most common management of dysphagia is diet modification by thickening food and beverages. This study aimed to obtain protein-based beverages for the dysphagia diets of the elderly, corresponding to the 'honey' (III) level of dysphagia fluids according to the National Dysphagia Diet classifications, and containing 100 g kg-1 of good-quality proteins with a high rate of hydrolysis during digestion. Four protein formulations made from pea proteins, milk proteins, a mixture of milk and pea proteins, and milk proteins with added konjac glucomannan, were evaluated on the basis of rheological characterization and proteolysis kinetics during in vitro digestion. The mixture of milk proteins and pea proteins, and the mixture of milk proteins with added konjac glucomannan, showed typical yielding pseudoplastic fluid behavior with similar apparent viscosity but different structural characteristics. These differences were the reason for the differences in proteolysis kinetics during digestion. The mixture of milk and pea proteins showed viscous liquid behavior and was more rapidly hydrolyzed under gastrointestinal conditions than mixtures containing milk proteins and konjac glucomannan acting as a weak gel system. We presume that geriatric consumers with swallowing difficulties may benefit from 'honey'-level viscosity, protein-based beverages containing pea and milk proteins through faster proteolysis and better bioaccessibility of amino acids during digestion. © 2020 Society of Chemical Industry.