**Abstract**

The majority of losses in horticultural produce occur during postharvest storage, particularly due to poor handling. Most fruit, especially climacteric fruit, have a short postharvest life due to an increase in ethylene synthesis which signals ripening and, subsequently, senescence. Traditional practices for preserving the postharvest quality of horticultural crops are chemical-based, a practice which has lately received enormous criticism. Recently, the use of postharvest illumination with LEDs as a nonchemical and environmentally friendly technique to preserve fruit and vegetables has been reported by various authors. Unique properties of LEDs such as low radiant heat, monochromatic nature and low cost have made this lighting gain popularity in the food industry. This paper, therefore, reviews the recent development in the postharvest applications of LEDs in horticultural crops, while focusing particularly on physical characteristics, nutritional value, and overall quality alterations of fruit and vegetables. According to the recently published research, red and blue LED lights are most valuable in terms of usage, while other wavelengths such as purple and yellow are slowly gaining attention. Furthermore, LEDs have been shown to affect fruit ripening and senescence, enhance bioactive compounds and antioxidants in produce, and prevent disease occurrence; however, there are some limitations associated with the use of this novel technology.

**Keywords:** bioactive compounds, irradiation, LED technology, nutrition, postharvest preservation, senescence, shelf life

### **1. Introduction**

The worldwide common challenge faced by farmers, especially in developing countries, is ensuring food security for a fast-growing world population. Recent predictions suggest that the demand for food will increase significantly as the predicted world population reaches about 9.7 billion people by 2050 [1]. On the other hand, about half (50%) of horticultural produce, mainly fruit and vegetables, is lost between harvest and consumption (postharvest) [2]. This, therefore, poses a threat and brings a serious concern to farmers to establish innovative methods and practices to increase the global food supply to provide sustainable living standards for humans by reducing the percentage of food lost in the value chain. Moreover, the consumption of fresh fruit and vegetables improves human health and wellbeing, because these commodities are rich sources of various vitamins, minerals, and antioxidant compounds that can prevent the occurrence of chronic diseases [3, 4]. As such, proper handling of horticultural crops is required, pre- and postharvest, to improve product quality and yield, thereby ensuring food and nutrient security for all humans.

The most reliable techniques that are currently used to preserve fruit and vegetables are cold storage and chemical additives. These chemical additives have come lately under criticism [5, 6] as consumers are aware of the possible negative implications these compounds can have on their health; as a result, there are limitations on the use of chemical additives for the preservation of horticultural produce. Industries in the agricultural sector have, therefore, shifted to nonchemical-based approaches such as light-emitting diode (LED) technology [7, 8]. This technology was adopted after the use of lights, such as fluorescent, high-pressure sodium, and incandescent lights, came under criticism due to their large emission of radiant heat and energy inefficiency [9], whereas LEDs could provide several advantages, including durability, low emission of radiant heat, adjustable size, and cool emitting surface, resulting in an environmentally friendly technology that is also economically favorable [10]. Initially, the LEDs were only used in growth chambers and greenhouses, whereas, after some time, LED technology improved, as there was an incorporation of the new semiconductor materials and improvement of the crystal growth techniques as well

#### **Figure 1.**

*Effect of LEDs on (A) the production of certain bioactive compounds, (B) postharvest quality, and (C) resistance to diseases affecting horticultural crops, adopted from] [12].*

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

as of optics [11], resulting in LEDs being used in postharvest horticulture. Recently, research on postharvest preservation of fresh horticultural produce with the use of LEDs has gained popularity. Various studies revealed that LEDs have the potential to enhance ripening, particularly color development, as well as being able to suppress disease occurrence and improve the overall nutritional quality of fruit and vegetables exposed to various LED wavelengths [**Figure 1**] [7, 11, 13, 14]. This review, therefore, focuses on the potential of postharvest application of LED technology on horticultural crops, discussing the most significant, recent findings related to this technology. The technology and mechanism of action involved in irradiation with LEDs and the limitations of postharvest LED lighting will also be discussed.
