Exploring the Potential of Carob (Ceratonia siliqua L.) in Functional Cookies Production rich in polyphenols

Abstract

Carob-based functional foods have recently gained considerable consumer interest as natural and sustainable alternatives due to their remarkable nutritional profile and associated health benefits [1]. These products are obtained from the pods of Ceratonia siliqua L., a tree native to Mediterranean regions, and are naturally sweet, caffeine-free, and rich in bioactive compounds such as polyphenols, dietary fibre, and essential minerals [2]. This work explores the potential of carob for the development of functional foods, focusing specifically on the analysis of carob seed flour, carob pulp flour, and flours obtained from by-products of primary carob processing. Preliminary analyses included the determination of total polyphenols (TPC) by Folin–Ciocalteu test, antioxidant activity through DPPH, ABTS, and FRAP assays, and the biophenolic profile using UHPLC-ESI/QTOF-MS. Among the analysed samples, pulp flour exhibited the highest TPC (337.86 mg GAE/g) and antioxidant activity (DPPH: 65.03 mmol TEAC/100 g; ABTS: 67.64 mmol TEAC/100 g; FRAP: 75.18 mg/mL Fe²⁺), followed by carob waste flour (TPC: 303.80 mg GAE/g; DPPH: 58.00 mmol TEAC/100 g; ABTS: 38.47 mmol TEAC/100 g; FRAP: 44.78 mg/mL Fe²⁺). In contrast, seed flour showed significantly lower values. The phenolic profile revealed a high presence of typical carob polyphenols, including gallic acid (61.4 mg/100 g), ellagic acid (28.3 mg/100 g), gallocatechin (33.2 mg/100 g), tannins (72.5 mg/100 g), and procyanidins (49.6 mg/100 g), known for their strong antioxidant and antiinflammatory properties. Due to its interesting functional potential, carob flours were employed in the formulation of high-nutritional-value cookies. Based on preliminary results highlighting its superior bioactive profile, carob pulp flour was used to fortify biscuits at 5%, 10%, and 20% (w/w). The resulting products showed significantly increased antioxidant capacity and total phenolic content compared to conventional formulations, confirming the potential of carob derivatives as valuable ingredients in the development of functional bakery products. A sensory evaluation conducted with a trained panel (n = 20) indicated a high level of overall acceptability. Biscuits enriched with up to 20% carob pulp flour received positive scores for aroma, taste, and texture, with descriptors such as "pleasantly sweet," "mildly chocolaty," and "smooth mouthfeel" prevailing. No significant defects in bitterness or astringency were reported at these levels, suggesting an optimal balance between nutritional enhancement and sensory quality. These findings support the inclusion of carob-based ingredients in health-promoting food applications and justify further research into their nutritional and technological potential.