Production of Dark Chocolate Using Degla Beida Date Sugar Enriched with Spirulina

Abstract

The growing demand for healthier and sustainable food products has encouraged the exploration of natural alternatives to refined sugar and the incorporation of functional ingredients with high nutritional and therapeutic value. In this context, the present study aimed to develop a functional chocolate formulation using sugar extracted from the local date cultivar Degla Beida as a natural sweetening agent, combined with Spirulina (Arthrospira platensis) as a source of bioactive compounds. The study also sought to evaluate the physicochemical and functional properties of the developed product. Water-soluble sugars were extracted from Degla Beida dates collected from the Reguiba region, El Oued Province (Southeastern Algeria), using aqueous extraction followed by freeze-drying. Physicochemical and biochemical analyses were performed to determine total sugars, reducing sugars, proteins, and total phenolic compounds using standard analytical methods. Subsequently, spirulina-enriched chocolate formulations were prepared, and their physicochemical, microbiological, and functional properties were evaluated.the obtained results showed that the extraction yield of Degla Beida date sugar reached 42.8%. Chemical characterization revealed high contents of total sugars (60.62 ± 0.26%) and reducing sugars (59.65 ± 2.01%), together with appreciable levels of proteins (12.35 ± 1.04%) and total phenolic compounds (29.58 ± 1.63%). Physicochemical analyses indicated a moisture content of 20%, a pH value of 6.36, a mineral content of 2.8%, and an electrical conductivity of 21.9 µS/cm, demonstrating suitable technological characteristics for chocolate manufacturing. The extracted date sugar contributed to improved texture, structural stability, sweetness, and sensory acceptability of the final product. Microbiological analyses confirmed the absence of pathogenic microorganisms, indicating satisfactory microbiological quality and product safety. Furthermore, antioxidant evaluation of the developed chocolate using the DPPH assay revealed a moderate radical-scavenging activity with an IC₅₀ value of 1.47 ± 0.19 mg/mL. In addition, the spirulina-enriched chocolate exhibited promising antibacterial activity against pathogenic bacteria, highlighting its potential as a functional food with added health-promoting benefits. These findings demonstrate that the combination of Degla Beida date sugar and Spirulina can be successfully used to produce a functional chocolate with enhanced nutritional value, antioxidant capacity, antibacterial potential, and desirable technological and sensory properties.