Simplified model cookie doughs containing two kinds of starches with different gelatinization characteristics, waxy corn starch (WCS) and high-amylose corn starch (HACS), were baked and evaluated by physical test methods and a sensory panel to study the effect of starch characteristics on the cookie quality.
WCS cookies showed a larger expansion in the vertical direction and smaller spread than HACS cookies. Both the physical and sensory evaluation revealed the hard texture of WCS cookies and significant shortness of HACS cookies. A continuous structure was observed in the defatted WCS cookies by SEM, which is considered to have been responsible for the expansion and the hard texture. Although the degree of gelatinization in both cookies was very low, that of the WCS cookies was slightly higher than that of the HACS cookies. DSC thermograms and scanning electron micrographs suggest the possible gelatinization of WCS granules in the cookie.
It is assumed that a continuous structure due to starch gelatinization led to expansion of the cookie during baking and a hard texture for the finished product, so that interruption of starch gelatinization might be essential to produce cookies with a short texture.