Valorization of Papaya Peel Waste: Optimizing Acid Hydrolysis for Enhanced Pectin Recovery and Comprehensive Functional Characterization

ABSTRACT The growing demand for sustainable, plant‐based biopolymers has increased interest in valorizing fruit‐processing by‐products like papaya peel, a nutrient‐rich waste. This study optimized acid hydrolysis conditions to extract pectin from papaya peel and characterized the recovered biopolymer. Using a 3 2 factorial design, pH (2.0 and 2.5), temperature (70 and 80°C), and extraction time (45 and 60 mins) were varied to evaluate effects on yield, galacturonic acid content, and functional groups. Optimal conditions (pH 2.0, 80°C, and 60 mins) yielded 12.82 ± 2.68% (w/w), pectin with high galacturonic acid content, indicating preserved structural integrity. FTIR analysis confirmed key hydroxyl, alkane, and ester groups, while HPLC‐RI validated compositional purity. A brine shrimp lethality bioassay showed low acute toxicity (LC 50 = 847 ppm), supporting safe food applications. SEM analysis was omitted to prioritize chemical and functional characterization. These findings position papaya peel as a promising alternative pectin source, contributing to circular bioeconomy and food waste reduction efforts.