The Effect of Spinach Powder and Egg-Shell Powder on Physicochemical and Edible Qualities of Gluten-Free Cake

Background: Replacement of the gluten is one of the challenging issues in the food industry, since producing nutritious and functionally acceptable gluten-free foods is difficult. The cake is a cereal-based product that attracts the consumers due to its various flavors, long shelf-life, and relatively low cost. Considering the competition in markets and the increased demand for functional and natural products, efforts have been made to improve nutritional and functional properties of the cakes by modifying their nutritional composition. Methods: In this research, the effect of spinach powder (0-30 %) and egg-shell powder (0-7%) was evaluated on physical characteristics (density, porosity, color, texture properties) and functional properties (Total phenol, DPPH, Ash, moisture content, crude fiber, Mineral content) of gluten free-cake. Results: The results indicated that increasing spinach powder reduced L* value, a* value, porosity, and hardness, while it increased the moisture content, density, ash, mineral content, total phenol, antioxidant activity, total fiber, and overall acceptance. Increase of the egg-shell powder increased moisture content, a* value, total phenol and was decreased overall acceptance. On desirability function method, gluten-free cakes formulated with 11.78% of spinach powder and 4% of egg-shell powder had the most and desired physicochemical quality. Conclusion: Overall, the results indicated that spinach powder and eggshell powder could offer promising sources for improving the functional properties and acceptability of gluten-free cakes.