Chia Seed Hydrogel as a Solid Fat Replacer and Structure Forming Agent in Gluten-Free Cookies

Gluten-free cookies based on rice and chickpea flour with reduced-fat and increased protein content compared with conventional commercial gluten-free cookies were developed and used as a base for further vegetable fat replacement with chia seed hydrogel. Rheological properties of chia seed hydrogel revealed that 8% gels exhibited the optimal properties as a fat substitute. Designed cookie samples were characterized for their chemical composition, fatty acid profile, mineral content, physical, textural and color parameters, and sensory properties. All gluten-free cookies developed in this study could be labeled as "a source of iron and potassium", while those with chia seed hydrogel and cocoa powder could bear the additional claim "high in zinc and magnesium". Fat replacement with chia seed hydrogel resulted in a more favorable fatty acid composition with a PUFA/SFA ratio over 0.40 and nonsignificant changes in the cookies' hardness, weight, eccentricity, and specific volume, indicating that the chia seed hydrogel addition did not disturb the cookie structure and texture. The results of the sensory analysis confirmed that it is possible to apply chia seed hydrogel to produce reduced-fat cookies with sensory properties comparable to their full-fat counterpart and available commercial samples, and they are more appealing than commercial reduced-fat gluten-free cookies.