Mechanical and rheological categorization of food patterns suitable for older adults with swallowing limitation

Abstract

The improvement in the nutritional status of older adults with swallowing limitations, as could happen in Alzheimer’s, has prompted modified-texture food design, including thick liquids that reduce the risk of aspiration. National Dysphagia Diet and the International Dysphagia Diet Standardization Initiative classified food accordingly with dysphagia severity level by literature sources without considering preparation and service conditions. The rheological and mechanical behavior of 34 liquid, 35 semisolid, and solid food commonly included in elderly menus was categorized by dysphagia severity level, considering preparation conditions and evaluation at service temperature. Data were fitted to the Power Law and Herschel-Bulkley models. Rheological behavior found thixotropic and pseudoplastic fluids in the range of 0.13 < n < 0.69; 0.48 < K < 62081, without elastic limit. Solid and semisolid food were classified by hardness as 4-pureed (H ≤ 15000), 5-Minced & moist, and 6-Soft & bite-sized (15000 ≤ H ≤ 40000), 7-Regular-Easy to chew (H > 40000). Analyzing the rheological and mechanical behavior attributes allowed the categorization by type of dysphagia. Outcomes for food with individualized attributes are useful for older adult caregivers at home and in professional clinical care, emphasizing people with cognitive impairment, including Alzheimer’s.