Flow properties of oral contrast medium formulations depend on the temperature.

BACKGROUND: During the therapeutic videofluoroscopic examination of swallowing, gradation of bolus volume, texture, and viscosity can be implemented to determine the optimal bolus characteristics in that particular patient. When a thickened liquid is given to a dysphagic patient it is served at room temperature. However, in these patients with a delayed oral and/or pharyngeal stage of swallow, the bolus is held for a long time in the oral cavity. The temperature of the thickened liquid thereby increases. PURPOSE: To study the rheological exploration (variation of viscosity with temperature) of thickened food used for radiologic swallowing examinations in patients with oral and pharyngeal dysfunction, in particular in mixtures of barium sulfate suspensions and in iodine solutions. MATERIAL AND METHODS: Deep-frozen mango purée was thawed at room temperature. It was then mixed with barium sulfate contrast medium to a density of 25% w/w. Resorce Thicken Up was mixed at room temperature at two concentrations: 4.3% w/w (4.5 g thickener + 100 g distilled water) and 6.0% w/w (4.5 g thickener + 70 g distilled water). The thickener consisted of modified corn starch. Resorce Thicken Up was also mixed at room temperature with two concentrations of an iodine contrast material, iohexol (Omnipaque, 350 mg I/ml). The two concentrations were: 4.3% w/w (4.5 g thickener + 100 g iohexol) and 6% w/w (6 g thickener + 100 g iohexol). Measurements were carried out from 20 degrees C to 37 degrees C using a Stresstech HR rheometer. The rheometer was equipped with a concentric cylinder measuring system (inner cylinder 15 mm). RESULTS: The samples containing thickener in water as well as in iohexol showed a dependence on thickener concentration and temperature. The mango purée with barium sulfate displayed very small temperature dependence. The thickener solutions in iohexol had significantly higher viscosity compared with the other thickener solutions and the mango purée. The relative decrease shows that mango purée, the 6% thickener solution in water, and solutions with iohexol exhibited similar relative viscosity change at different temperatures. CONCLUSION: Our conclusion is therefore that it is important always to make the solution with high precision. It is also of importance to observe how long the patient keeps the bolus in the mouth. This might vary and actually it may not be possible to influence this factor. When different types of thickeners are compared, it is important to take into account the temperature at which the thickener is observed.

A meal concept designed for older adults - Small, enriched meals including dessert.

BACKGROUND: The population of older adults is growing and many are at risk of disease-related malnutrition. This is a serious condition which increases the risk for other diseases and distress, human suffering and puts a high load on health care costs. Meal concepts tailored to suit the needs of older adults are required to decrease the incidence of disease-related malnutrition. OBJECTIVE: To evaluate sensory perception regarding a concept of small, protein and energy-enriched multi-component meals designed according to the nutritional needs of older adults. DESIGN: A meal concept of small main courses with complementary desserts and protein and energy-enriched products was evaluated using triangle tests, hedonic evaluation and focus group discussion. Enriched sauces and meals were compared to corresponding commercial products regarding appearance, taste, consistency and overall acceptance. RESULTS: The concept of a small main course with a complementary dessert was generally perceived as positive by the target group. The acceptance scores for the enriched meals were generally lower than for the commercial meals, mainly owing to the packaging of the enriched meals which required covering the food in sauce. Enriched sauces contained approximately 90% more protein than the commercial sauces. However, protein enrichment affected the sensory properties of the sauces and they were perceived as thicker, creamier and less flavour-intensive. CONCLUSIONS: A concept based on small, protein and energy-enriched meals supplemented with a dessert was considered suitable for increasing the energy and protein intakes of older adults provided that the method of enrichment ensures attractive sensorial properties.

Objective and quantitative definitions of modified food textures based on sensory and rheological methodology.

INTRODUCTION: Patients who suffer from chewing and swallowing disorders, i.e. dysphagia, may have difficulties ingesting normal food and liquids. In these patients a texture modified diet may enable that the patient maintain adequate nutrition. However, there is no generally accepted definition of 'texture' that includes measurements describing different food textures. OBJECTIVE: Objectively define and quantify categories of texture-modified food by conducting rheological measurements and sensory analyses. A further objective was to facilitate the communication and recommendations of appropriate food textures for patients with dysphagia. DESIGN: About 15 food samples varying in texture qualities were characterized by descriptive sensory and rheological measurements. RESULTS: Soups were perceived as homogenous; thickened soups were perceived as being easier to swallow, more melting and creamy compared with soups without thickener. Viscosity differed between the two types of soups. Texture descriptors for pâtés were characterized by high chewing resistance, firmness, and having larger particles compared with timbales and jellied products. Jellied products were perceived as wobbly, creamy, and easier to swallow. Concerning the rheological measurements, all solid products were more elastic than viscous (G'>G''), belonging to different G' intervals: jellied products (low G') and timbales together with pâtés (higher G'). CONCLUSION: By combining sensory and rheological measurements, a system of objective, quantitative, and well-defined food textures was developed that characterizes the different texture categories.