Texture Standarization And Characterization Of Liquid Foods For Elderly Dysphagia And Clinical Test

With the growth of age,the physiological functions and body co－ordination were significantly weakened.The swallowing dysfunctions will directly affect the eating and nutrition among elderly.With fast growing of aged populations,how to provide appropriately texture-modified food or fluids for elderly people has caused a great concern to the societies and governments.In order to solve this problem,we need to establish a unified dietary classification standard.Currently,some developed countries have put forward dietary standards according to their national needs,but no uniform definition of dietary standards is available across to globe.This study was based on the dietary texture standard proposed by the International Dysphagia Diet Standardization Initiative(IDDSI)which was found in 2013.A natural thickener Sodium Carboxymethyl Cellulose(CMC)and five kinds of commercial thickening products were used for to study.Their texture properties were analyzed and graded.Correlations between texture grades and the grade of swallow disorders were established.The main aim of this study was to provide dysphagia patients a feasible texture guide and to provide theoretical and technological back up to industry in new product development and to the government in policy making.Main research contents and results are summarized as:1)The flow test provided by IDDSI is an efficient method to assess texture level of liquids.This study focused on the classifications of product solutions,rheological properties of solutions were measured by transient viscosity test,time sweep,steady viscosity test.The study found that apart from CMC solutions behaved as Newtonian at low shear rates,all other sample systems showed pseudoplastic behavior within the shear rate from 0.1 to 1000 s-1.Apparent shear viscosity did not change significantly with time,so that the all samples didn’t have thixotropy or rheopecticity.Fitting the curve of viscosity-shear rate curve collected by steady viscosity test,obtained the apparent shear viscosity value at 50 s-1 shear rate.The results show that samples at same IDDSI level presented similar behavior except the CMC solution at the boundary between of IDDSI 3 grade and 4 grade.2)Two differ back extrusion rigs were used to simulate the swallow procedure via Texture Analyzer,simulating fluid flow speed were 0.05,0.1,0.5,1,5,10 mm/s respectively.Results showed that simulating swallow index were altered by the increasing swallowing speed.We analyzed the simulating work and simulating driving force at the speed of 10 mm/s and found that four simulating indexes were able to distinguish liquids based on different IDDSI levels.In addition,it was worth mentioning that the ball back extrusion rig performance were better than plate back extrusion,and simulating driving force based on ball back extrusion were also more effective than force based on plate back extrusion.3)This study enrolled 26 volunteers with dysphagia or at risk of dysphagia from Huadong Hospital.Patients’ dysphagia grade was assessed by Water Swallow Test.Assessment of a suitable IDDSI fluid level was conducted by modified Volume-Viscosity Swallow Test(V-VST).The results showed that there were 5,7,7,7 subjects separately assessed in dysphagia grade 1,2,3,4.And the patients with dysphagia of grade 1,2,3 and 4 were suitable for liquid foods with IDDSI grade 0 and above,grade 1 and above,grade 2 and above,grade 3 and above,respectively.A significant positive correlation between dysphagia severity and suitable IDDSI fluid level had been identified(R~2 = 0.815).