Gluten-Free Flatbread with Carob Flour and Sourdough: Nutritional Composition, Technological Properties and Storage Stability

The growing demand for clean-label foods has stimulated interest in minimally processed ingredients capable of improving the nutritional and technological quality of gluten-free bakery products. Carob (Ceratonia siliqua L.) is an underutilized Mediterranean crop whose seeds are mainly used for locust bean gum production, while other fractions of the fruit remain insufficiently valorized. This study investigated the potential of carob seed flour (CSF) and the whole carob fruit flour (pods and seeds; CSPF) as natural structuring ingredients in gluten-free flatbread (GFFB), combined with sourdough fermentation. The initial technological properties (pasting profile, baking loss, specific volume, color, and texture profile) and nutritional composition were evaluated, alongside storage stability, through textural and sensory changes during 72 h. The incorporation of carob ingredients improved the nutritional profile of GFFB, nearly doubling total dietary fiber and iron content without compromising sensory acceptance. CSF use resulted in an improved pasting profile and a 50% softer crumb structure. Sourdough fermentation successfully mitigated the increased hardness and lower sensory freshness perception in CSPF formulations. Carob seed flour, as well as whole carob fruit flour combined with sourdough, represent effective natural strategies for improving the technological properties, nutritional quality, texture profile, and freshness perception of gluten-free flatbread without compromising sensory acceptability.