The Physical Properties, Structure, and Sensory Characteristics of Cookies Replacing Lotus Seed Flour and Low Glycemic Index Sugar

Replacing high-glycemic index (GI) ingredients in cookie formulations can help reduce dietary sugar intake but often alters structural and sensory attributes of the final product. This study aimed to investigate the feasibility of incorporating lotus seed flour (rich in resistant starch) and various sweetener (maltitol, stevia, and erythritol) to develop cookies with minimal alterations in structure and sensory properties compared to a control sample, while lowering sweetness and GI. In this investigation, lotus seed flour replaced wheat flour at 10%, 20%, 30%, and 40% substitution levels. Sweeteners were incorporated at 25%, 50%, 75%, and 100% of the sugar content (maltitol, erythritol), corresponding to equivalent sweetness levels (stevia). Physical parameters (diameter, thickness, spread ratio, volume) and structural properties (hardness, as well as microstructural observations via scanning electron microscopy) were evaluated, alongside consumer acceptance. The results demonstrated that a 20% substitution of wheat flour with lotus seed flour produced cookies with optimal hardness and a desirable porous structure. Substituting 75% of the sugar with maltitol or erythritol, or 25% with stevia, yielded cookies whose structural characteristics closely resembled those of the control sample. While stevia and erythritol increased thickness but reduced diameter and volume, maltitol had minimal effects on cookie shape. Replacing 100% of the sugar content with any of the alternative sweeteners led to an increase in hardness, with stevia and erythritol producing notably firmer cookies. Overall, a 75% maltitol substitution emerged as the most favorable level, inducing minimal structural changes and offering higher sensory acceptance compared to stevia and erythritol.