Stimulation of Light-Emitting Diode Treatment on Defence System and Changes in Mesocarp Metabolites of Avocados Cultivars (Hass and Fuerte) during Simulated Market Shelf Conditions

Abstract

The ability of light-emitting diode (LED) light treatment to reduce the anthracnose decay via its eliciting effects and thus induce resistance in the avocado (Persea americana), was investigated in this study to replace the current postharvest fungicide treatment. In experiment 1, the effect of blue or red LED lights (6 h per day) on the incidence of anthracnose in artificially inoculated (Colletotrichum gloesposorioides) and naturally infected avocados (cv. Fuerte and Hass) at 12–14 °C (simulated market shelf) for 4, 8, 14, and 16 days was investigated. In experiment 2, the effect of blue or red LED lights on the induced defence mechanism, fruit metabolites, antioxidant activity, and percentage of fruit reaching ready-to-eat stage was determined. Exposure to red LED light significantly reduced the anthracnose decay incidence in naturally infected cv. Fuerte on day 12 and in cv. Hass on day 16 compared to the prochloraz fungicide treatment by upregulating the PAL genes and maintaining the epicatechin content. Blue LED light accelerated the ripening in both cultivars, probably due to reduced D-mannoheptulose content. Red LED light exposure for 6 h per day and 12 days storage showed potential to replace the prochloraz treatment with improved ascorbic acid content and antioxidant activity.

Genetic Diversity and Association Analysis among Germplasms of Diospyros kaki in Zhejiang Province Based on SSR Markers

“…In this study, mean temperature of the quarter showed little significance in morphological traits, perhaps due to all sampling sites belonging to the subtropical monsoon climate and no strict temperature limit for persimmon survival. Consistent with previous studies of many fruit trees, which revealed that light [59][60][61] and water supply [62][63][64][65][66] played an important cue in both leaf and fruit development, and precipitation and solar radiation were the main climate factors affecting the morphological traits of persimmon in Zhejiang Province. There were also longitudinal differences in morphological trait diversity.…”

Changes in Functional Compounds, Volatiles, and Antioxidant Properties of Culinary Herb Coriander Leaves (Coriandrum sativum) Stored Under Red and Blue LED Light for Different Storage Times

“…The LED blue light treatments could have induced the activation of the shikimate pathway to increase the concentration of the precursors for the production of different phenolic compounds via the phenylpropanoid pathway ( 41 ). Red LED light increased the biosynthesis of flavonoid (epicatechin) in avocados by inducing the upregulation of phenylalanine ammonia-lyase gene expression ( 11 ). However, Liu et al ( 42 ) showed that compared to red light, the blue light-induced a higher flavonoid accumulation in Cyclocarya paliurus leaves, especially key health-promoting flavonoids such as kaempferol, and quercetin.…”

“…Furthermore, in yellow and green fresh-cut sweet peppers, red LED light and in red fresh-cut sweet pepper, blue LED light enabled the accumulation of phenolic compounds by inducing the activity of phenylalanine ammonia-lyase (PAL) ( 10 ). In avocados, red LED lights improved the accumulation of epicatechin content in the fruit by upregulating the PAL genes ( 11 ). LED red light treatment improved the lycopene and β-carotene, total phenols, and flavonoids in tomatoes during post-harvest storage ( 10 ).…”

“…LED red light treatment improved the lycopene and β-carotene, total phenols, and flavonoids in tomatoes during post-harvest storage ( 10 ). Conversely, blue LED treatment improved the lycopene, chlorogenic acid, caffeic acid, and rutin content after 7 days of storage ( 11 ). Moreover, the red or blue LED lights improved the antioxidant properties of fresh produce and are regarded as an efficient strategy to increase health-promoting compounds to add health benefits to the consumers ( 12 ).…”

Brassica microgreens cabbage (Brassica oleracea), radish (Raphanus sativus) and rocket (Eruca vesicaria) (L.) Cav: application of red‐light emitting diodes lighting during postharvest storage and in vitro digestion on bioactive compounds and antioxidant activity

“…Prior studies have demonstrated that phytochromes (PhyA to PhyE) absorb red light and are essential for synthesising phenolic compounds and antioxidants (Li & Kubota, 2009). Maroga et al (2019) and Mpai & Sivakumar (2020) suggest that red LED light activates phenylalanine ammonia lyase (PAL), which produces secondary metabolites (phenols). Reported that light enhances the production of phenolic content by creating malonyl CoA and coumaroyl CoA.…”