Relationship rheology-functionality in thickeners formulations to dysphagia pacients

Abstract

The swallowing in dysphagic patients happens in a disorderly manner, which may result in the aspiration of liquid foods and can lead to dehydration, malnutrition, asphyxia and even death. This condition can be improved by the use of thickeners that modify the rheological properties of liquids to assist their food intake. Although the viscosity modification of the diet is commonly used as a palliative strategy to circumvent the consequences of dysphagia, its efficacy has not been fully understood, since the influence of the different rheological properties of the food on the swallowing process is very difficult to quantify. This difficulty is due to the mechanical complexity of the process that involves shearing and extensional forces, besides the strong influence of the process shear rate (velocity consumption). The key to a safe swallowing is the coordination between the rheological attributes of the bolus, the mechanical forces applied by the oro-pharyngeal muscles and biomechanical activities used to protect the airway. The relationship between these factors has not been established, imposing several limitations to the development of appropriate thickening formulations. In addition, currently commercial thickening formulations have a high cost, generic information of preparation regardless of the physicochemical properties of the food to be thickened. Moreover, they are often rejected by the patient caused by texture modification besides the increase of the glycemic index in starch-based formulations. The commercial alternative to reduce the sensory rejection by the dysphagia patients is the incorporation of xanthan gum in these formulations. Moreover, no conventional thickeners such as flaxeed mucilage, have interesting functional properties. It can be used in the treatment of gastrointestinal disorders that is quite common in patients with dysphagia. Thus, the general objective of this proposal is to evaluate the systems with thickeners based on flaxseed gum, xanthan and starch to be incorporated in different liquid food matrices under different conditions of preparation and consumption. These systems will be evaluated in relation to their rheological and tribological behavior, in vitro digestibility and glycemic index of the thickeners. The results may not only contribute to the development of thickeners with improved acceptance and functionality, but also help to the understanding of the correlation between rheological/tribological to the better perceptions of dysphagia patients. (AU)