Antioxidant and Preservative Effects of <scp> <i>Epilobium angustifolium</i> </scp> Extract in Beef Burgers Products: Physicochemical Properties, Color Stability, Lipid Oxidation, and Molecular Docking Analyses

Consumers are increasingly seeking natural alternatives to synthetic preservatives in meat products. This study evaluated the effects of willow <i>E. angustifolium</i> extract on beef burgers' physicochemical properties, color stability, and lipid oxidation during refrigerated storage. The extract demonstrated significant antioxidant activity, with a total phenolic content of 1263.48 mg GAE/L and a total flavonoid content of 278.43 mg ce/L. The pH values of the beef burgers decreased over time, with significant effects on Days 4 and 8 in the treated groups, except T1. The color properties, including lightness (<i>L</i>*), redness (<i>a</i>*), and yellowness (<i>b</i>*), were affected by the plant extract, with 1 g and 3 g concentrations leading to darker and redder hues. Moreover, adding 9 g extract led to discoloration due to increased <i>b</i>* values. Thiobarbituric acid-reactive substances analysis showed increased lipid oxidation, with the T3 group (9 g extract) exhibiting higher values, suggesting a prooxidant effect at higher concentrations. Gas chromatography-mass spectrometry analysis identified a range of phytochemicals, including α-pinene and β-thujone, which contributed to the complex, volatile profile of the extract. High-performance liquid chromatography analysis revealed the presence of significant phenolic compounds, such as ascorbic acid and gallic acid, with high antioxidant potential. Molecular docking studies indicated that gallic acid exhibited a moderate binding affinity with the target protein 9R-lipoxygenase (5EK8), followed by β-thujone and α-pinene, suggesting their potential as bioactive compounds in food preservation. The results provide insights into the functional potential of <i>E. angustifolium</i> extract as a natural antioxidant and preservative in meat products.