Pectin from durian peel (Durio zibethinus Murr.) - a novel reducing and stabilizing agent: Physicochemical properties, green synthesis of silver nanoparticles and antimicrobial properties

Sustainable agricultural development has become a long-term trend to protect environmental health, human well-being and enhance economic profitability all over the world, especially in developing countries like Vietnam. Thus, in order to elevate the value of Durio zibethinus Murr., this study aims to extract pectin from the peels waste and initially investigate its reduced capacity in the green approach for silver nanoparticle synthesis. The extraction yield was 11.21 % for crude pectin and 6.89 % after purification. Physiochemical characterization showed that the acidic isolated pectin was low methoxy pectin with 40 % DE and has a viscosity-molecular weight of 25.5 kDa with 60 % AUA. Spherical and stable pectin-based Ag nanoparticles prepared in alkaline medium exhibit a hydrodynamic diameter approximately 100 nm and a negative potential around -50 mV. In particular, green synthesized Ag nanoparticles with negative charge outer coating demonstrated their antibacterial ability against both gram (-) Escherichia coli and gram (+) Staphylococcus aureus at the MIC of 61.8 ppm. In consequence, durian pectin probably serves as a novel reducing and stabilizing agent for size-controlled nanoparticles synthesis.