UV and Visible Spectrum LED Lighting as Abiotic Elicitors of Bioactive Compounds in Sprouts, Microgreens, and Baby Leaves-A Comprehensive Review including Their Mode of Action.

Francisco Artés-Hernández,Lorena Martínez-Zamora,Noelia Castillejo

doi:10.3390/foods11030265

Abstract

Background: According to social demands, the agri-food industry must elaborate convenient safe and healthy foods rich in phytochemicals while minimising processing inputs like energy consumption. Young plants in their first stages of development represent great potential. Objective: This review summarises the latest scientific findings concerning the use of UV and visible spectrum LED lighting as green, sustainable, and low-cost technologies to improve the quality of sprouts, microgreens, and baby leaves to enhance their health-promoting compounds, focusing on their mode of action while reducing costs and energy. Results: These technologies applied during growing and/or after harvesting were able to improve physiological and morphological development of sprouted seeds while increasing their bioactive compound content without compromising safety and other quality attributes. The novelty is to summarise the main findings published in a comprehensive review, including the mode of action, and remarking on the possibility of its postharvest application where the literature is still scarce. Conclusions: Illumination with UV and/or different regions of the visible spectrum during growing and shelf life are good abiotic elicitors of the production of phytochemicals in young plants, mainly through the activation of specific photoreceptors and ROS production. However, we still need to understand the mechanistic responses and their dependence on the illumination conditions.

Highlights

Horticultural products are the most important and most-studied foods as a source of nutraceutical compounds
Phenolic content increased by 45% and 65%, and carotenoid content increased by 279 and 220% after B + R and B + R + FR, respectively
Preharvest UV and visible spectrum light-emitting diodes (LEDs) illumination has been widely developed in recent years to increase the crop yield, especially in vertical farming, where the conditions can be customised and monitored throughout the growing period to obtain phytochemicalenriched products with reproducible quality attributes

Summary

Introduction

Horticultural products are the most important and most-studied foods as a source of nutraceutical compounds. Young plants in their first stages of development as sprouts, microgreens, and baby leaves have been demonstrated having more than 20-fold bioactive compound content compared to adult plants [2,3]. This makes them an important source of phytochemicals with a great benefit to be included in our daily balanced diet. The agri-food industry must elaborate convenient safe and healthy foods rich in phytochemicals while minimising processing inputs like energy consumption Young plants in their first stages of development represent great potential. We still need to understand the mechanistic responses and their dependence on the illumination conditions

Objectives

Results

Conclusion