Alginate-coated functional wrapping paper incorporated with sulfur quantum dots and grapefruit seed extract for preservation of potato hash browns

Abstract

This study explores the impact of alginate-based functional coatings incorporating sulfur quantum dots (SQDs) and grapefruit seed extract (GFSE) on the antioxidant and antibacterial properties of kraft paper for food packaging. Applying these coatings effectively fills the porous interfibrillar spaces of the paper, significantly improving oil resistance and mechanical properties. However, the water vapor permeability and moisture absorption rate decreased slightly due to the hydrophilic nature of constituents. In particular, the addition of 5 wt% SQDs to the paper coating formulation resulted in remarkable antioxidant activity, with approximately 100% reduction in ABTS and 60% reduction in DPPH free radicals. The addition of SQDs significantly reduced the bacterial cell viability of E. coli and L. monocytogenes by ∼2 log CFU/mL and ∼4.5 log CFU/mL, respectively. Co-addition of SQDs and GFSE significantly improved antimicrobial activity with ∼3 log CFU/mL reduction of E. coli and complete (100%) eradication of L. monocytogenes even at lower concentrations (2.5 wt% each). The lipid oxidation in the hash brown potato patties wrapped in functional coated paper was reduced by nearly 50% compared to uncoated paper. This effect persisted even after an extended storage period of 15 days, demonstrating the superior ability of the coated paper to improve the shelf life of processed, ready-to-eat foods.