Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit

Abstract

SummaryThe objective of this study is to investigate the eff ects of irradiation from light-emitt ing diodes (LEDs) on several fruits during storage. To improve storage and increase the contents of some bioactive compounds, apple, tomato and red bell pepper fruits were exposed to yellow light emitt ed from the diodes at 590 nm. The contents of ascorbic acid, total phenolics, total fl avonoids and several pigments were investigated, along with the antioxidant potential. The colour parameters (L*, a* and b*) and fi rmness of the fruit were also determined. Aft er 7 days of LED light irradiation, there was signifi cantly higher total phenolic content and antioxidant potential in apple peel extracts. The irradiated fruit of tomato had signifi cantly higher levels of total phenolic compounds, and the fruit of red bell pepper had signifi cantly higher antioxidant potential. LED light had no eff ects on the colour parameters, although there was a tendency to accelerate colour development. Apple fruit irradiated with LED light was signifi cantly less fi rm. Among twelve analysed pigments, signifi cantly more β-carotene was detected in LED light-irradiated apple and bell pepper fruit, more α-tocopherol and γ-tocopherol in bell pepper fruit, and more lutein in apple peel and bell pepper fruit. The applied LED light slightly accelerated the ripening of the studied fruit, and aff ected the synthesis of some of the secondary metabolites.

Post-Harvest Use of Ultraviolet Light (UV) and Light Emitting Diode (LED) to Enhance Bioactive Compounds in Refrigerated Tomatoes

“…This is in contrast with previous studies that reported significant increases in total phenolic compounds in LED-treated tomatoes stored from 5 to 10 days under a controlled room temperature (19–20 °C) [ 10 , 11 ]. However, our results are more in line with those reported in tomatoes exposed to yellow LED light and stored for 7 days at a lower temperature (10 °C) [ 20 ]. Yellow LEDs are also known to enhance the ripening of fruits along with induction of the synthesis of antioxidant compounds, including (poly)phenols and carotenoids [ 15 ].…”

Challenges and Opportunities of Light-Emitting Diode (LED) as Key to Modulate Antioxidant Compounds in Plants. A Review

“…The Vit C content was high in crisphead lettuce, especially under GL irradiation because of the deeper light transmittance [ 83 ]. When apple peel, tomato, and red bell pepper fruit were irradiated with YL, there was no significant increase in Vit C content compared to the control samples stored in the dark [ 84 ].…”

“…There is evidence that LED lighting can influence the shelf life and quality of fresh produce, inhibiting weight loss, senescence, and over-ripening, and enhancing the production of antioxidant compounds [ 55 , 56 , 73 , 98 , 108 , 135 ]. Most of the results showed that BL promotes the accumulation of phytochemical constituents, including polyphenol in bananas ( Musa acuminate ) [ 100 ], Vit C in citrus juices ( Citrus unshiu and Citrus sinensis ) [ 72 ], Chinese cabbage ( Brassica campestris ) [ 75 ], and strawberry ( Fragaria ananassa ) [ 75 ], and anthocyanin in sweet cherries ( Prunus avium ) [ 84 ] and in Chinese bayberry fruit ( Myrica rubra ) [ 185 ]. In other studies, BL shows less effective results, compared to other light treatments.…”

An Overview of LEDs’ Effects on the Production of Bioactive Compounds and Crop Quality

“…Moreover, tomatoes treated with blue LEDs become firm, accumulate higher levels of free amino acids, including γ-aminobutyric acid-GABA, when compared with tomatoes kept under dark condition [ 45 ]. Blue or yellow LEDs are also known to enhance ripening of fruits along with induction of the synthesis of β-carotene, lutein, α-tocopherol and γ-tocopherol when compared with fruits under dark conditions [ 42 , 47 , 56 ]. Quick ripening occurs due to the increased rates of respiration and ethylene production caused by the LEDs [ 42 , 47 ].…”