ISOCHORIC PRETREATMENT AND NANOCOMPOSITE PACKAGING IMPACT ON VITAMIN C AND MICROBIAL STABILITY OF JUTE MALLOW

Abstract

Rapid moisture loss, nutritional deterioration, and microbial spoiling are the main causes of postharvest losses in leafy vegetables. The quality of jute mallow leaves subjected to isochoric pretreatment and nanocomposite packaging during refrigerated storage was assessed in this study. Starch-based nanocomposite films reinforced with peanut shell nanoparticles were produced for packaging, and an isochoric pretreatment chamber was designed and built to provide a constant-volume thermodynamic environment under subfreezing temperatures. The chamber maintained stable constant-volume conditions during cooling. Vitamin C content declined from 0.74 ± 0.10 to 0.46 mg/100 g ± 0.01 during storage, while total viable count and yeast and mold count increased from 5.04 log₁₀ to 6.14 log₁₀ CFU/g and YMC from 2.61 log₁₀ to 3.73 log₁₀ CFU/g, respectively, over 15 days, although all samples maintained microbiological stability. The 18 μm nanocomposite film provided better microbial control and storage stability than the 16 μm film. Overall, the combination of isochoric pretreatment and nanocomposite packaging, effectively preserved the nutritional and microbiological stability of jute mallow leaves, demonstrating its potential as a sustainable preservation approach for highly perishable leafy vegetables.