MODULE 1: METHODOLOGY AND TOOLS DEVELOPMENT FOR ADULT EDUCATORS

The supply of foods with modified texture and thickened fluids is the basis for the nutritional treatment of dysphagia.

Thin liquids are the type of product that most easily causes choking and should be thickened to improve bolus control and to help prevent aspiration. A range of starches and gums has historically been used to thicken liquids.

On the other hand when solid food is pureed, it may also require the use of thickening agents to adjust the rheological and textural characteristics, if they are not achieved by the culinary preparation and/or the reduction of size particle..

In the past, thickening foods and fluids with starches such as wheat flour, corn flour or tapioca starch, was commonplace: Gravies and custards are homemade fluids that have used these starches for many years. When the grains of starch come into contact with boiling water they absorb the water and expand, thickening the fluid. Unfortunately, when left to cool, the starch may break down and the product ‘weeps’ water. Domestic thickening using ingredients containing starch naturally in its composition (potato, bread….) is also possible, but it is still rarely used in the diets guided by caregivers and health professionals.

Nowadays, modified starches and vegetable gums are preferred. They act as thickening agents, gelling agents, emulsifiers and stabilizers.

Modified starches, proteins, individually or in combination with exudates and seed gums, seaweed extracts and, most recently, microbial polysaccharides, are found to have the ability to improve product mouthfeel, handling properties, and stability characteristics.

Commercial thickeners are also available and include different thickening agents (from those cited above) in their composition. However, they may be considered expensive by some patients. In addition, in some places, they are not easily found in common commercial establishments and those factors limit the acquisition.

Tips for proper thickening of liquids and foods

• The type and amount of thickener and the characteristics of the food or beverage (dispersing media) are relevant factors.

• Time after preparation is a key factor, as consistency changes with time.

• Temperature is also a critical factor.

• The right consistency is very important, since thickened liquids which are nevertheless still thin, are swallowed quickly by the patients and may flow prematurely into the pharynx.

• Sticky and adherent textures, along with fine liquids should be avoided, because these textures may cause food residues to accumulate in the oropharynx and lead to aspiration after swallowing.

• Excessive thickening can also cause negative effects, as it can leave residues inside the pharynx, which may incur risk of aspiration, reduce palatability, and increase viscosity, in addition to generating changes in consistency and cohesiveness.

• When preparing the liquid beverage, the liquid may become lumpy if it is stirred too slowly or if more thickener is added once it has started to thicken.

• It takes approximately 5–15 min for its physical properties to stabilize.