Biochemical and physiological effects of LED light on postharvest metabolism of horticultural produce: A review

Abstract

Fruits and vegetables, while nutritionally rich, are highly perishable and vulnerable to postharvest losses driven by both physiological and microbial factors. Conventional preservation methods such as cold storage and chemical treatments raise concerns about energy use, cost, and chemical residues. In this context, light-emitting diode (LED) technology has emerged as a non-thermal, energy-efficient, and sustainable solution. This review synthesizes current findings on the effects of specific LED wavelengths on postharvest biochemical pathways such as ethylene biosynthesis, respiration, enzymatic activity, antioxidant defense mechanisms, and secondary metabolite production. Blue and red LED lights, in particular, modulate the activity of key enzymes like catalase (CAT), peroxidase (POD), ACC oxidase, and phenylalanine ammonia-lyase (PAL), while influencing pigment biosynthesis, chlorophyll degradation, and microbial resistance. These responses contribute to shelf-life extension, ripening regulation, and the retention of nutritional and sensory quality. Despite promising results, the research remains fragmented and crop-specific. This review underscores the need for standardized protocols and further exploration into the biochemical underpinnings of LED-induced postharvest responses, to facilitate broader and more effective adoption.