Exploring the Interactive Effects of γ-Tocopherol, Ellagic Acid, and β-Sitosterol in Iron Walnut Oil

Abstract

Iron walnut oil is recognized for its high content of polyunsaturated fatty acids and bioactive compounds, which face significant oxidative stability challenges during storage and processing. This study investigates the antioxidant interactions among γ-tocopherol, ellagic acid, and β-sitosterol in iron walnut oil during the thermal oxidation, aiming to enhance its oxidative stability. The antioxidant efficacy of γ-tocopherol, ellagic acid, and β-sitosterol, both individually and in combination, was evaluated. γ-Tocopherol demonstrated the strongest antioxidant activity, and its combination with ellagic acid exhibited a synergistic effect (SE), markedly enhancing the oxidative stability of iron walnut oil by reducing hydrogen peroxide formation and preserving unsaturated fatty acids, whereas β-sitosterol exhibited limited efficacy, suggesting antagonistic interactions. The effects on fatty acid profile and polar components were analyzed via nuclear magnetic resonance (NMR) and total polar content analysis. The findings suggest that optimizing natural antioxidant combinations can effectively extend the shelf life of iron walnut oil and improve its application potential in the food industry, aligning with the demand for clean-label and sustainable products.

Practical Application: The study provides valuable insights for food industry professionals working with polyunsaturated fatty acid (PUFA)-rich oils. By demonstrating that γ-tocopherol and ellagic acid significantly enhance the oxidative stability of iron walnut oil, the research offers practical guidance for formulating walnut oil-based products with extended shelf life. These findings can directly inform the development of natural antioxidant systems in food preservation, aligning with consumer demands for clean-label and sustainable products. Researchers can use this information to optimize antioxidant combinations in various food formulations, potentially reducing waste and improving the nutritional profile of food products. The study also highlights the importance of careful antioxidant selection to avoid antagonistic interactions, which is crucial for the industrial application of health-focused products.