Lychee peel extract-based magnetic iron oxide nanoparticles. Sustainable synthesis, multifaceted antioxidant system, and prowess in eco-friendly food preservation

Abstract

The quest for sustainable synthesis methods has led to the exploration of lychee peel extract (LCPEx) as an ecofriendly alternative in the field of nanomaterials. This groundbreaking study introduces the synthesis of lychee peel extract-based magnetic iron oxide nanoparticles (LCPEx-MIONPs) and delves into their diverse applications. The meticulous methodology involved a multistep process for lychee peel extraction, resulting in the creation of LCPEx. The subsequent synthesis of LCPEx-MIONPs, achieved by combining the extract with iron chloride as a precursor and sodium hydroxide as a pH adjustor (set to 7.5), yielded nanoparticles with nanoscale dimensions (8.7± 0.4 nm) and diverse morphologies (cubic, hexagonal, spherical). Comprehensive characterization techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), unveiled the structural attributes of LCPExMIONPs. The LCPEx exhibited robust antioxidant activity against DPPH, reaching its maximum inhibitory within only 5 minutes in a simple disc diffusion. The multifaceted antioxidant system of LCPEx-MIONPs exhibited an IC50 value of 202.3 µg/mL, highlighting the synergistic effects of lychee phytochemicals and magnetic ions. Beyond antioxidant capabilities, LCPEx-MIONPs, when incorporated into banana-based food preservation films, demonstrated significant prowess in grape preservation. The controlled release properties led to a notable reduction in water loss (9.3% on day 3 and 19.7% on day 6) compared to control grapes without LCPEx-MIONPs incorporated (18.2% on day 3 and 34.8% on day 6). This study significantly contributes to green nanotechnology, food preservation, and the development of eco-friendly hydrogels and bioplastic films, emphasizing the versatile applications of LCPEx-MIONPs in antioxidants, sustainable food preservation, and hydrogel-based bioplastics.