Green Synthesis of Copper Nanoparticles from Pineapple Peel Dietary Fibers: Antibacterial, Antifungal, Antioxidant, and Antidiabetic Activities

Dietary fiber-based approaches have recently gained notable attention in biomedical applications due to their biocompatibility, biodegradability, and eco-friendliness. Ripe Ananas comosus (pineapple) peel, typically discarded as waste, is a rich source of soluble dietary fiber, cellulose, and hemicellulose. In the present study, a green method was employed for first-time synthesis of copper nanoparticles (Cu-Nano) using dietary fiber extract derived from A. comosus peel powder. UV-Visible analysis and ATR-FTIR spectroscopy confirmed the reduction of copper ions and successful synthesis of Cu-Nano. The nanoparticles exhibited hydrodynamic diameter of 253.6 nm, confirming their nanosized dimensions, and showed zeta potential of −17.34 mV, indicating good colloidal stability. Furthermore, HR-TEM analysis revealed uniformly dispersed spherical particles with average diameter of 6.57 ± 1.50 nm, while XRD analysis confirmed their crystalline nature. The Cu-Nano exhibited significant antibacterial activity against Staphylococcus aureus and Escherichia coli, as well as antifungal activity against Aspergillus niger and Fusarium moniliforme. Additionally, Cu-Nano demonstrated strong antioxidant activity (IC50: 88.27 ppm) and effective inhibition of α-amylase (IC50: 420.32 ppm), indicating promising antidiabetic potential. In conclusion, green-synthesized Cu-Nano utilizing dietary fibers from pineapple peel waste represents promising multifunctional therapeutic platform with potent antimicrobial, antioxidant, and antidiabetic effects, holding significant potential for future biomedical applications.