Effects of soy flour formulation and pretreatment on the properties of gluten-free cookies: A comprehensive study from flour, dough, to baked products.

Grain-based gluten-free cookies are often nutritionally inferior owing to their low protein content. This study aimed to enhance the nutritional value of gluten-free cookies by incorporating soy flour and to investigate the effects of different types of modified soy flour on the properties of gluten-free dough and cookies. Results indicate that all types of modified soy flour significantly decreased water absorption capacity (p < 0.05) and protein molecular weight while significantly increasing free sulfhydryl groups and free amino group content (p < 0.05). Adding modified soy flour significantly reduced the mixograph peak time from 7.26 min to less than 1.9 min (p < 0.05). Incorporating 30 % cysteine-modified soy flour significantly increased the cookie spread ratio from 9.2 to 22.8 (p < 0.05). Moreover, adding modified soy flour maintained the moderate hardness and fracturability of gluten-free cookies and achieved a more desirable color.