Standardization and Safety Challenges of Green Nanoparticles in Food Systems: A Comprehensive Review

Green nanotechnology has emerged as a promising framework for developing sustainable, biocompatible nanomaterials that align with circular-economy principles. Plant- and food-waste-derived nanoparticles (PFW-NPs) have gained considerable attention for applications across food packaging, preservation, sensing, and agriculture. This review aims to critically examine the current state of PFW-NPs, with particular emphasis on the challenges of standardization, reproducibility, and safety assessment. It synthesizes recent advances in synthesis pathways, mechanistic insights, characterization methods, and functional applications, while evaluating the limitations that hinder regulatory approval and large-scale adoption. Their synthesis relies on naturally occurring phytochemicals that function as reducing and stabilizing agents, offering an environmentally responsible alternative to conventional chemical routes. However, significant obstacles persist due to variability in biomass composition, diverse extraction methods, poorly defined reaction conditions, and insufficient data on cytotoxicity, nanoparticle-food interactions, gut microbiome effects, and environmental fate. To address these gaps, the review proposes a structured framework that includes minimum information reporting guidelines, reference materials, high-throughput and computational tools, and circular-economy-aligned production strategies. Coordinated methodological, regulatory, and interdisciplinary efforts will be essential to realizing the full potential of PFW-NPs in shaping safer, more sustainable food systems.