Non-iron oxygen scavengers in food packaging: mechanisms, applications, and the shift towards green alternatives

Abstract

Oxygen exposure in packaged foods accelerates oxidative spoilage, microbial growth, and sensory degradation. Although iron-based oxygen scavengers dominate current applications, concerns about safety, recyclability, and consumer acceptance have driven interest in non-iron alternatives. This review critically examines recent developments in natural and synthetic non-iron oxygen scavengers, including antioxidants (ascorbic acid and tocopherol), unsaturated hydrocarbons (polybutadiene), enzymes (glucose oxidase and catalase), microorganisms, and polyphenolic plant extracts (gallic acid and catechu). Reported oxygen scavenging capacities range from 6.44 mL O₂ g⁻¹ (α-tocopherol) to 200 mL O₂ g⁻¹ (polybutadiene), with activation often triggered by moisture, UV light, or pH. Plant-based systems, such as catechu–calcium carbonate combinations, stand out as biodegradable and food-safe alternatives, making them especially suitable for moisture-rich foods. Compared to conventional iron-based scavengers, these systems offer advantages in terms of safety, sustainability, and consumer appeal. This review further discusses activation mechanisms, incorporation into polymer matrices, regulatory issues, and barriers to commercialization. Emerging trends include biodegradable films, multifunctional packaging, and smart indicators, which highlight non-iron oxygen scavengers as promising solutions for safer and more sustainable active packaging.