Production and properties of low-glycemic index cookies from retrograded water yam starch

A primary challenge for functional foods, such as low-glycemic index (GI) products, is poor consumer acceptance which limits their market success. This study utilized a sensory-driven strategy, employing a Box–Behnken response surface methodology (RSM) with overall sensory score as the primary optimization criterion, to develop cookies substituting wheat flour with retrograded water yam starch (RtS). The optimized formulation (achieving a maximal predicted sensory score of 8.221) was obtained at 39.24% RtS substitution, 157.13 °C baking temperature, and 29.54 min baking time. Comparative sensory analysis revealed that the RtS cookies significantly outperformed commercially available healthy cookies in overall acceptability. Subsequent in vivo validation confirmed the product’s functional benefit, revealing an in vivo GI (iGI) of 44.37, classifying it as a low-GI product (