**4. Postharvest application of LEDs in horticultural crops**

The majority of horticultural crops, particularly fruit and vegetables, undergo rapid ripening postharvest due to an increase in respiration and metabolic activities, resulting in the deterioration in quality, softening, rapid water loss, tissue destruction, and senescence. This happens more so in climacteric fruit, as they continue the ripening process, even if removed from the mother plant. Postponing senescence, extending shelf life, and maintaining quality characteristics of horticultural produce are pivotal to reduce postharvest losses and ensure that appealing, high-quality produce reaches the consumer. This can be achieved by storing horticultural produce properly and exposing the produce to effective senescenceinhibiting treatments [24, 25]. The use of LED lights as a sustainable postharvest treatment offers unique opportunities to not only maintain but even improve produce characteristics.

The response of fruit and vegetables to irradiation with different spectral lights (wavelengths) varies and depends on the absorbing ability of the specific light wavelengths [10]. As such, the application of single-wavelength red and blue LEDs has been effective in enhancing bioactive compounds, phenolics, flavonoids, and other antioxidants in fresh fruits and vegetables, while maintaining their nutritional status and overall quality [7, 12] (**Table 1**). Recently, other wavelengths have started to gain interest and are producing promising results as a study by Xie et al. [30] demonstrated that purple LED light (40 μmol m−2 s−1) enhances the concentration of ascorbic acid and carotenoids of broccoli florets, and a different study by Zhou et al. [31] revealed that irradiation with white LED light (10 μmol m−2 s−1) is effective in maintaining postharvest quality and delaying senescence of pak choi during storage. On the other hand, mixed spectral light ratios, particularly blue:red at different ratios, have recently been adopted and proven to increase the efficiency of LED lighting [7, 12, 23, 26] (**Table 1**). Furthermore, research has shown that LED illumination can alter carotenoid accumulation and prevent fungal spoilage, which contributes


*An Overview of the Recent Developments in the Postharvest Application of Light-Emitting… DOI: http://dx.doi.org/10.5772/intechopen.109764*


**Table 1.**

*Postharvest effect of various LED lights on postharvest behavior of horticultural crops.*

significantly to postharvest losses (**Table 1**) [11], a study by Dhakal and Baek [32] revealed that short-period exposure with blue wavelength to red tomatoes can extend the postharvest shelf life of tomatoes by delaying color development, and our recent study on cherry tomatoes also achieved the same results and documented improved phytochemical concentrations in blue-wavelength-treated tomatoes [20]. The postharvest effects of LEDs have also been tested on minimally processed food, and promising results have been achieved [35]; however, further research on such commodities is required to optimize exposure duration and type (wavelength).
