Textural Classification of Commercial Foodstuffs for Dysphagia Using Back-Extrusion Test

Oropharyngeal dysphagia (OD) management requires texture-modified foods (TMFs). The International Dysphagia Diet Standardization Initiative (IDDSI) framework classifies TMFs from drinks (levels 0-2) to purées and soft-solid foods (levels 3-4). However, current instrumental methods for analyzing commercial OD-oriented TMFs often fail to provide reliable classifications, limiting their clinical and industrial applicability. This study aimed to evaluate the effectiveness and reliability of the Back-Extrusion Test (BET) in classifying commercial OD-oriented TMFs according to the IDDSI framework. Fifty-four commercial TMFs were analyzed using BET1 method (firmness and adhesiveness), and BET2 method (firmness, consistency, cohesiveness, and cohesion work). A progressive increase in firmness and consistency was detected as IDDSI level rose, with significant differences between levels. The classification accuracy for IDDSI levels, as determined by discriminant analysis, was 66.1% (BET1) and 76.8% (BET2), although both methods showed reduced performance, particularly for level 4 foods. Cluster analysis revealed three groups by means of BET1 and BET2, identifying levels of foods with low, intermediate, and high textural complexity. This finding suggests that a simplified classification framework could improve objectivity and reliability in assessing OD-oriented TMFs. Furthermore, integrating additional instrumental techniques may improve the accuracy classification of commercial foods where BET methods fail.