Extraction of melanin from black sesame seeds and its incorporation as a functional ingredient in pectin, agar and gelatin based ternary film for potato greening prevention application

Post-harvest greening of potato tubers ( Solanum tuberosum L.) is caused due to light-induced chlorophyll production and concurrent glycoalkaloid (α-solanine and α-chaconine) buildup. The increasing demand for clean-label, sustainable food preservation solutions worldwide is at odds with conventional packaging techniques which mostly rely on non-biodegradable synthetic plastic packaging. The current study aimed on the extraction and characterization of melanin from black sesame seeds ( Sesamum indicum L.) and to assess its functional efficiency when incorporated into ternary biopolymer edible coating system made of pectin, agar and gelatin (PEC/AGR/GEL) to prevent greening and quality deterioration. High purity and distinctive functional groups have been confirmed by UV-Vis and FTIR characterisation. Melanin when added to the biopolymer matrix enhanced the film's hydrophobicity, decreased water vapour permeability (1.687 ± 0.113 × 10 −9 g/m 2 Pa s) and increased radical scavenging activity to 90.40%. The 5% melanin coating successfully preserved ascorbic acid levels (16.17 ± 1.265 mg/100g) and pH stability (6.27 ± 0.015) while inhibiting chlorophyll synthesis by about 80% as compared to uncoated controls in a 30-day shelf-life testing conducted in direct sunlight. These findings show that melanin-reinforced biobased edible coatings offer a high-performing, environmentally friendly substitute for synthetic packaging in maintaining the quality and reduce the visible greening of potatoes. Future research will concentrate on quantitatively assessing glycoalkaloid concentrations and scaling the coating application process.