Gymnema sylvestre-Fortified Spheres and Beads from Waste Biomass: A Circular Bioeconomy Approach for Functional Food Delivery

Abstract

This work offers a novel circular bioeconomy approach for producing functional food delivery platforms with antidiabetic potential by combining brown seaweed, Sargassum cinctum, avian eggshell waste, and Gymnema sylvestre extract. Sodium alginate extracted from S. cinctum yielded a 25% yield, whereas calcium chloride recovered from eggshells demonstrated 89.14% efficiency. FTIR spectroscopy confirmed structural integrity with characteristic carboxylate peaks (1600, 1400 cm⁻¹) for alginate and Ca-Cl stretching (689.66, 516.92 cm⁻¹) for calcium chloride. Calcium chloride exhibits heat stability up to 700°C and alginate breakdown at 220-230°C, according to thermogravimetric analysis. G. sylvestrefortified spheres (3.87±0.31 cm) and beads (0.54±0.06 cm) were made by ionic gelation at an optimal sodium alginate concentration of 4%. The spheres had a total phenolic content of 27.77±1.29 mg GAE/g, a flavonoid content of 19.16±0.56 mg QE/g, and a nitric oxide scavenging activity of 72.66% at 10 mg/mL. At 100 μg/mL, enzyme inhibition tests showed αamylase (30.1%) and α-glucosidase (31.1%) inhibition, which was much less than acarbose (>90%). Studies on pH-dependent release showed that phenol was released more quickly at pH 1.2 (80.53±0.87% by 120 min) and more slowly at pH 6.8 (59.13±0.83% by 180 min). Korsmeyer-Peppas investigation revealed anomalous transport mechanisms (n=0.94-0.98), and kinetic modeling revealed the Higuchi model as the best relevant descriptor (R²>0.97). Despite somewhat lower taste scores (6.38-6.87), sensory examination revealed acceptable consumer perception (total acceptability 8.07-8.5 on a 9-point scale). This integrated approach effectively turns multiple waste streams into biodegradable functional carriers with pH-responsive release characteristics, even if bioactive loading adjustment is still required for commercial viability.