Isolation, characterization and bioactive properties of polysaccharides extracted from the peel of Cucumis melo Mill. (Gurvak variety)

Melon peel is a by-product that contains significant amounts of bioactive substances. It has potential for developing functional foods. In this work, we studied the chemical composition of melon peel from the Gurvak variety, including various fractions of polysaccharides and their monosaccharides, free amino acids, water-soluble (WS) vitamins and flavonoids. The fractions of WS, acidic and basic polysaccharides were obtained with yields of 14.5 %, 4.60 % and 5.63 %, respectively. Their viscosity results were linked with the carboxyl group-related parameters and molecular masses. The dominant molar mass of free amino acids was attributed to nonessential amino acids, with glycine and glutamine being the most abundant ones. In the peel pulp, flavonoids and vitamins were determined in nanomolar and micromolar concentration, respectively. After oral administration at a dose of 5000 mg/kg, the WS polysaccharides showed no toxicity in mice. Furthermore, the fraction exhibited wound-healing properties that accelerated skin recovery in mice. The polysaccharides extracted from the melon peel of the local Gurvak variety may be used as a wound-healing source. In terms of free amino acids, both the quantity and quality may not be appropriate for functional foods. A similar conclusion can be drawn made for quantities of flavonoids and vitamins. The results obtained can serve to expand knowledge and support further analysis in this discipline, which may lead to technological improvements.