Effect of Magnesium Oxide Nanoparticles Synthesized From <i>Malus domestica</i> Borkh. on Shelf Life of <i>Spinacia oleracea</i> L.

ABSTRACT Spinach ( Spinacia oleracea L.) is a nutritious leafy green vegetable that can be eaten raw or cooked. Spinach contains 2.9% protein, 3.6% carbohydrates, 0.4% fat, and 91.4% water, along with high levels of vitamins, carotenoids, and polyphenolics. Postharvest deterioration of spinach, primarily driven by spoilage microorganisms such as Pseudomonas and Aspergillus niger , highlights the urgent need for effective preservation strategies. Sustainable packaging and eco‐friendly storage approaches are essential to reducing food loss, safeguarding nutritional integrity, and mitigating adverse environmental impacts. The study aims to extend the shelf life of Spinacia oleracea (L.) by using green‐synthesized Magnesium oxide nanoparticles. Nanoparticles were synthesized using an aqueous leaf extract of Malus domestica (Borkh.) and different concentrations of Magnesium nitrate hexahydrate salt (10, 20, and 30 mM) to produce nanoparticles of varying sizes. The nanoparticles were characterized using UV, SEM, and XRD techniques. The antimicrobial activity of MgO‐NPs was tested against bacterial strains ( Xanthomonas oryzae , Pseudomonas aeruginosa ) and fungal strains ( Aspergillus niger, Fusarium oxysporum ) responsible for spinach leaf spoilage. Nanoparticles with a size of 28 nm exhibited stronger antimicrobial effects. The germination, growth, and shelf life of Spinacia oleracea were assessed by applying 28 nm MgO‐NPs at different concentrations (T1‐50 ppm, T2‐100 ppm, T3‐150 ppm) and salt controls (T4‐50 ppm, T5‐100 ppm, T6‐150 ppm) at 4°C and 25°C. Treatment T1 at 4°C effectively extended the shelf life of Spinacia oleracea (L.) by an average of 18 days.