Sensory and instrumental acceptance thresholds of pounded yam stretchability/extensibility by UAC-FSA, Bénin

A main quality attribute of pounded yam is its extensibility/stretchability, with yams exhibiting high values ​​being preferred by consumers. This study assessed the sensory and instrumental acceptance thresholds of stretchability through consumer testing, quantitative descriptive analysis (QDA), Kieffer dough extensibility and dynamic rheology analyses performed on twenty varieties in two experiments. Significant differences were evidenced among yam varieties for all studied parameters. Furthermore, stretchability was predicted by instrumental extensibility by Kieffer dough method (R2 = 0.61) or G’-G” crossover (R2 = 0.77). A high stretchability is preferred by consumers, with the desirable sensory score above 8.01, on a 10 cm unstructured line scale, corresponding to biophysical targets values above 3.38 mm for kieffer dough extensibility (distance while stretching using texturometer) and below 1.52 kPa for G’-G” crossover (using rheometer). Thus, Kieffer dough textural or dynamic rheology analyses are practically relevant in understanding the extensibility of pounded yam, and can be carried out to screen the various yam genotypes and determine textural thresholds for pounded yam extensibility.