Physicochemical and microbiological stability of gluten-free cookies formulated with coconut and almond flours

Abstract

Gluten-free bakery products have gained increasing popularity due to health concerns associated with gluten consumption, including conditions such as gluten intolerance. The absence of gluten in flour-based ingredients poses considerable technological challenges, particularly in maintaining desirable product quality. Therefore, our study aimed to develop gluten-free cookies using alternative ingredients and to evaluate their physicochemical and microbiological stability during storage. Gluten-free cookies were formulated using almond flour and coconut flour as wheat flour substitutes, while erythritol was used to replace sucrose at substitution levels ranging from 0 to 100%. The results showed that substituting wheat flour with almond flour had minimal effects on the physicochemical characteristics and microbiological quality of the cookies. The substitution of sucrose with erythritol at levels of 0–100% resulted in only slight changes in cookie quality. However, increasing the proportion of coconut flour as a substitute for almond flour affected product characteristics. Higher coconut flour levels led to an increase in lightness (L) and a decrease in redness (a*) and yellowness (b*). Moreover, moisture content and water activity (a_w) tended to increase with higher coconut flour proportions. No pathogenic bacteria, including Escherichia coli, Staphylococcus aureus, and Salmonella spp., were detected in any formulation throughout the 60-day storage period. These findings suggest that almond flour-based formulations provide greater storage stability, while coconut flour may increase moisture and water activity. The study demonstrates the potential application of almond and coconut flours in producing nutritious and microbiologically safe gluten-free cookies suitable for health-conscious consumers.