Effect of conductive hydro-dried active packaging on the oxidative stability of peanuts

Abstract Lipid oxidation is a key factor contributing to quality deterioration in high-fat foods like peanuts, limiting shelf life and consumer appeal. While conventional aluminum-laminated plastic packaging provides effective protection, its environmental impact prompts interest in more sustainable alternatives. This study examines two-layer composite films composed of a plastic film and an antioxidant-incorporated edible film, designed to preserve roasted peanuts during 8-month storage. To achieve this, sodium alginate- and sodium caseinate-based films containing sodium ascorbate were produced using the innovative conductive hydro-drying method, forming a multilayer structure as the edible layer dried directly onto the conventional plastic film. Water activity, color, lipid oxidation parameters (free fatty acidity, peroxide value, p-anisidine value, conjugated dienes, and aldehydes), and sensory attributes were evaluated. Conductive hydro-dried active films effectively slowed oxidation and demonstrated performance comparable to commercial packaging in physicochemical properties, lipid oxidation, and sensory responses. Free fatty acidity remained around 0.7 mg KOH/g oil in active (PAA and PCA) and commercial (T) packages. Despite a rapid increase from an initial 8.5 meq/kg, peroxide values in PCA- and T-packaged samples remained below 27 meq/kg over 8 months, unlike the control and P groups, which exceeded 30 meq/kg. Similarly, ρ -anisidine values remained within legally permitted limits for both active and commercial packaging. Sensory panelists did not detect off-odors at the end of storage and rated active-packed samples similarly to peanuts stored in commercial films. These results support the potential of this technology as a sustainable packaging approach for oxidation-sensitive foods.