Physicochemical and Sensory Profiling of Carob Flour and Effects of Its Incorporation on Quality Characteristics of Wheat-Based Biscuits

This study evaluated carob (Ceratonia siliqua L.) flour as a functional ingredient for improving the nutritional and sensory properties of wheat-based biscuits. Mature carob pods collected from eastern Algeria were processed into fine flour and characterized for physicochemical properties, antioxidant activity, and volatile and phenolic profiles. GC–MS analysis revealed a complex volatile profile dominated by organic acids, aldehydes such as furfural and benzaldehyde, and Maillard-derived compounds, including 2-acetylpyrrole and furfuryl alcohol, associated with caramel and cocoa-like aromas. LC-MS profiling identified several flavonoids and phenolic acid derivatives, including quercetin-, myricetin-, and kaempferol-glycosides, as well as gallic acid glucoside, confirming the high antioxidant potential of carob flour. Biscuits were formulated by substituting wheat flour with 30% and 60% carob flour. Sensory evaluation revealed significant increases in color intensity, caramel odor, sweetness, and chocolate-like flavor (p ≤ 0.05), with the 30% substitution achieving the highest overall acceptability. These sensory attributes were associated with the volatile and phenolic profiles, particularly the presence of Maillard-derived furans and flavonoid compounds. These findings demonstrate that carob flour can enhance the sensory characteristics and contribute to the functional potential of biscuits, supporting its use as a natural cocoa substitute and source of bioactive compounds in bakery products.