title: Rheological Characterization and Cluster Classification of Iranian Commercial Foods, Drinks and Desserts to Recommend for Esophageal Dysphagia Diets.
abstract: BACKGROUND
  In the absence of dysphagia-oriented food products, rheological characterization of available food items is of importance for safe swallowing and adequate nutrient intake of dysphagic patients. In this way, introducing alternative items (with similar ease of swallow) is helpful to improve quality of life and nutritional intake of esophageal cancer dysphagia patients. The present study aimed at rheological characterization and cluster classification of potentially suitable foodstuffs marketed in Iran for their possible use in dysphagia diets.
  
  
  METHODS
  In this descriptive study, rheological data were obtained during January and February 2012 in Rheology Lab of National Nutrition and Food Technology Research Institute Tehran, Iran. Steady state and oscillatory shear parameters of 39 commercial samples were obtained using a Physica MCR 301 rheometer (Anton-Paar, GmbH, Graz, Austria). Matlab Fuzzy Logic Toolbox (R2012 a) was utilized for cluster classification of the samples.
  
  
  RESULTS
  Using an extended list of rheological parameters and fuzzy logic methods, 39 commercial samples (drinks, main courses and desserts) were divided to 5 clusters and degree of membership to each cluster was stated by a number between 0 and 0.99.
  
  
  CONCLUSIONS
  Considering apparent viscosity of foodstuffs as a single criterion for classification of dysphagia-oriented food products is shortcoming of current guidelines in dysphagia diets. Authors proposed to some revisions in classification of dysphagia-oriented food products and including more rheological parameters (especially, viscoelastic parameters) in the classification.
authors.affiliation: 1. Dept. of Food Science and Technology, Faculty of Nutrition Sciences, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences , Tehran, Iran.
authors.forename: Azizollaah
authors.initials: A
authors.lastname: Zargaraan
authors.affiliation: 2. Tehran Medical Branch, Islamic Azad University, Khaghani St, Shariati Ave , Tehran, Iran.
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Omaraee
authors.affiliation: 3. Dept. of Human Nutrition and Dietetics, Shahid Beheshti University of Medical Sciences, National Nutrition and Food Technology Research Institute , Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Rastmanesh
authors.affiliation: 4. Network Management Centre, Ministry of Health and Medical Education , Tehran, Iran.
authors.forename: Negin
authors.initials: N
authors.lastname: Taheri
authors.affiliation: 1. Dept. of Food Science and Technology, Faculty of Nutrition Sciences, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences , Tehran, Iran.
authors.forename: Ghasem
authors.initials: G
authors.lastname: Fadavi
authors.affiliation: 5. Dept. of Food Technology, Ayatollah Amoli Branch, Islamic Azad University , Amol, Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Fadaei
authors.affiliation: 1. Dept. of Food Science and Technology, Faculty of Nutrition Sciences, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences , Tehran, Iran.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Mohammadifar
keywords: Diet; Esophageal dysphagia; Esophagus cancer; Food Industry; Rheology