Impact of spectral composition of light from light-emitting diodes (LEDs) on postharvest quality of vegetables: A review

Postharvest illumination with light-emitting diodes (LEDs) is an emerging, non-chemical, residue-free technique used to preserve plant commodities. This paper aimed to review current knowledge on postharvest LED illumination on vegetables while focusing on their effect on the physical, nutritional, and microbial quality of vegetables. Most of the studies on postharvest illumination have concentrated on continuous LED treatment over photoperiod/cycle illumination. LED illumination from different wavelengths preserved or improved the nutritional value (ex: chlorophyll, lycopene, vitamin C, and phenolic compounds), stimulated antioxidant enzyme activity in some vegetables while effectively reducing the membrane damage, and maintaining membrane integrity. According to the available research data, light from red, blue, and white LEDs is ostensibly effective on the physiological process of a variety of vegetables. Further, LEDs can be used in non-thermal means to inactivate foodborne pathogens considerably. Therefore, postharvest LED lighting with different wavelengths can be considered an excellent alternative lighting system to preserve safe and nutritious fresh vegetables.