Postharvest Exogenous Melatonin Treatment of Table Grape Berry Enhances Quality and Maintains Bioactive Compounds during Refrigerated Storage

Abstract

Table grape berries are classified as a perishable crop that deteriorates quickly after harvest. The application of melatonin after harvest was found to be effective for retarding senescence and slowing ripening. In the current study, we tested the influence of two melatonin concentrations (50 and 100 µmol) as a postharvest application on quality, bioactive compounds, and enzyme activities of grape berries cv “Crimson” stored at 0 ± 1 °C and 90% relative humidity (RH) for 35 days. Our results indicated that melatonin application extends the shelf-life of berries by reducing weight loss and maintaining total soluble solids (TSS), titratable acidity (TA), berry adherence strength, and firmness. Melatonin treatment also reduced pectin methyl esterase (PME) and polygalactouranase (PG) enzyme activities compared to the control. Moreover, O2•− and H2O2 rates in berries were reduced by high melatonin concentration. Moreover, peroxidase (POD) and catalase (CAT) enzyme activities were increased by melatonin application. Our findings suggested using melatonin postharvest to increase shelf life and maintain quality attributes during refrigerated storage, which could be advantageous on a large scale.

Exogenous melatonin delays oxidative browning in litchi during cold storage by regulating biochemical attributes and gene expression

“…The outcome of our investigation shows that melatonin administration has a positive impact on the TSS, TA, and total sugar content of preserved fruits and treatment with 0.5 mM melatonin retained the highest content of TSS, TA, and total sugar. Several other researchers have also reported that melatonin administration delayed the decline of TSS during storage (Miranda et al, 2020;Nasser et al, 2022). Similarly, administration of melatonin in strawberries (Liu et al, 2018), pitaya (Ba et al, 2021), kiwi fruit (Wang et al, 2019), jujube (Wang et al, 2022), and citrus navel orange (Ma et al, 2021) during postharvest storage resulted in less degradation of TSS and TA.…”

Role of Melatonin in Directing Plant Physiology

“…Medina-Santamarina et al [118] described that the quality parameters of pomegranate fruits like fruit size, color, total acidity, total soluble solids, fruit number per tree, and fruit yield were improved by the application of MT. Nasser et al [128] observed that the increase in transcriptome alterations during the ripening process in grape berries enhanced the quality of berries due to MT treatment. Under drought stress, foliar application of MT enhanced the yield and quality of Moringa oleifera L. in terms of amino acid composition, glutamic acid, and nutrition such as nitrogen, phosphorus, potassium, calcium, and magnesium [129].…”

Ultrasound synergistic slightly acidic electrolyzed water treatment of grapes: Impacts on microbial loads, wettability, and postharvest storage quality

“…This trend may be attributed to a growing public awareness of the health benefits associated with consuming fresh fruits, such as their provision of bioactive components known for antioxidant and anticancer properties [3] . However, grapes are particularly prone to microbial contamination postharvest, leading to spoilage and potential food safety concerns, which negatively impact their storage longevity and market competitiveness [4] . The issue of postharvest loss is not limited to grapes alone; globally, fruits and vegetables experience loss rates between 28 and 36 %, with rates in China reported as 20–30 % [5] .…”