ScholarWorks@중앙대학교

초록

Fungal infection remains the primary cause of postharvest blueberry decay. As a non-thermal technology, light-emitting diode (LED) offers a promising approach to preservation by inhibiting fungal activity. This study investigated the antifungal effects and mechanisms of LED against the main spoilage fungi (Penicillium sclerotiorum and Cladosporium cladosporioides) in blueberries and its application potential for preservation. Under optimal conditions (410–420 nm LED, 25°C, 12 h), LED treatment achieved spore inhibition rates of 99.46–99.52 % in vitro. The in vivo study using inoculated blueberries, under the same conditions (extended to 36 h), demonstrated maximum log reductions of 4.11 and 2.50 CFU/g for the two fungi, respectively. Based on these, the antifungal mechanism was further elucidated through cellular and molecular analyses. At the cellular level, results indicated that cellular membrane damage (lipid peroxidation and intracellular leakage), oxidative stress (ROS accumulation and diminished antioxidant enzyme activities), and mitochondrial dysfunction (ΔΨm dysregulation and ATP depletion) are the main causes of cell damage. Molecular analysis revealed that LED disrupted structural integrity by suppressing cell wall/membrane biosynthesis genes, impaired antioxidant defense by inhibiting peroxisome biogenesis (P. sclerotiorum) and GSH synthesis genes (C. cladosporioides), and dysregulated energy metabolism by altering key genes in glycolysis, TCA cycle, and oxidative phosphorylation. Furthermore, compared with the untreated control, the LED treatment had no significant effect on the blueberries' color, soluble solids, and pH, though it increased weight loss and reduced firmness. These findings suggest a novel LED-based preservation strategy for blueberries and provide a theoretical basis for its application.

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