Postharvest preservation of fruits and vegetables by light-emitting diodes

Postharvest losses of fruits and vegetables remain a major challenge because of rapid physiological deterioration, microbial spoilage, and quality degradation during storage and distribution. Light-based technologies, particularly light-emitting diodes (LEDs) and ultraviolet (UV) irradiation, have emerged as promising non-thermal and residue-free approaches for preserving postharvest quality through precise regulation of wavelength, intensity, and exposure duration. However, reported responses remain highly variable across species, cultivars, developmental stages, and treatment conditions, limiting the establishment of predictive and standardized strategies. Previous reviews have focused primarily on either technological applications or specific mechanistic pathways, whereas an integrated understanding across preharvest and postharvest systems remains limited. This review provides a comparative and comprehensive analysis of LED- and UV-mediated regulation across the preharvest-postharvest continuum. Specifically, it synthesizes evidence on the light regulation of fruit growth and development, spectral effects on photosynthesis, metabolism and molecular pathways, enhancement of antioxidants and bioactive compounds, postharvest shelf-life extension, microbial control, senescence regulation, and quality preservation. Additionally, this review critically evaluates the methodological variability, translational limitations, and challenges associated with commercial implementation. Unlike existing reviews, this work integrates wavelength-specific physiological, biochemical, and molecular responses with practical considerations and cross-study comparisons to identify inconsistencies and emerging trends. By emphasizing mechanistic understanding, evidence-based synthesis, and future research priorities, this review provides a framework for developing predictive, crop-specific, and scalable light-based preservation strategies that may contribute to sustainable postharvest management and reduced food losses in horticultural systems.