Potential of Artichoke Leaves to Preserve Beef Burgers’ Quality Through Different Strategies: Direct Incorporation (Leaf Powder or Lyophilised Leaf Extract) or Covered with Antioxidant Bioactive Films

Abstract Artichoke leaves are a promising natural source of antioxidants. This study explores the valorisation of this by-product as a new ingredient to preserve beef burgers’ quality through different strategies: directly mixed as leaf powder (ALP) or as lyophilised leaf extract (LE), and through the incorporation of ethanolic (EE) or lyophilised leaf extract into different bioactive films (made of gelatin (GF-EE/GF-LE) or alginate (AF-EE/AF-LE)). Films were characterised by FTIR, SEM, mechanical properties, and polyphenol release kinetics. The quality of burgers (stored at 4 °C) was evaluated during 7 days through lipid oxidation (Thiobarbituric Acid Reactive Substances, TBARS), metmyoglobin (MetMb) formation, colour deterioration, changes in pH, and microbial growth. Positive (C + , burger with commercial antioxidants) and negative (C − , burger meat) controls were also assessed. Burgers with ALP or LE showed the lowest TBARS values (0.037 and 0.080 mg MDA/kg meat), both comparable to C + (0.050 mg MDA/kg meat), whereas C − exhibited higher lipid oxidation (0.24 mg MDA/kg meat). ALP also reduced MetMb formation in burgers until the third day (~ 44.3%), but compromised their sensory characteristics (flavour and texture). In contrast, burgers covered with films showed higher MetMb (50.7–61.1%) and had better consumer acceptance. Gelatin films released more polyphenols (slope, 0.0042 and 0.0034 mg GAE/mL for GF-LE and GF-EE, respectively) than alginate films (slope, 0.0026 and 0.0029 mg GAE/mL for AF-LE and AF-EE, respectively), thus reducing lipid oxidation more effectively. These findings support the potential of artichoke leaves as a natural antioxidant source to replace synthetic additives in meat products.