Polysaccharides of the Peel of Two Types of Сucumis Melo (Torpedo, Obi-Navvat) and Their Antimicrobial and Prebiotic Activity

The growing global population has increased the demand for food and created challenges in managing agricultural waste. Melon (Cucumis melo L.) peels, a byproduct of melon processing, hold potential as a source of biologically active compounds, including polysaccharides and phenolic acids, with antimicrobial, antioxidant, and prebiotic properties. This study aims to isolate and characterize polysaccharides from melon peels and evaluate their biological activities, providing a sustainable approach to waste utilization. Melon peel samples of the Torpedo variety were collected during the ripening period in Uzbekistan. Sequential extractions were performed using solvents (chloroform, ethanol, ammonium oxalate, and potassium hydroxide) to isolate water-soluble polysaccharides (WSPS), pectic substances (PS), and hemicellulose (HMC). Monosaccharide composition was analyzed using paper chromatography (PCh), gas chromatography (GC), and high-performance liquid chromatography (HPLC). Antimicrobial activity was assessed against opportunistic bacteria, and prebiotic activity was evaluated using Pediococcus acidilactici as a model strain. The extraction yielded 8.0 g of WSPS, 5.0 g of PS, and 2.0 g of HMC per 100 g of raw melon peel. Monosaccharide analysis revealed the presence of galactose, glucose, mannose, xylose, arabinose, and rhamnose. The antimicrobial assay demonstrated significant inhibition zones for pathogenic bacteria, suggesting strong antibacterial activity of melon peel polysaccharides. Additionally, prebiotic activity assays showed enhanced growth of Pediococcus acidilactici, indicating the potential of melon peel polysaccharides as prebiotic agents. The results highlight the potential of melon peel polysaccharides as functional biomolecules with antimicrobial and prebiotic properties. Their ability to inhibit bacterial growth and promote probiotic strains suggests applications in food preservation and gut health. Further studies on their structural characterization and bioactivity could enhance their utilization as natural additives or therapeutic agents, contributing to sustainable waste management and value addition in agriculture.