Blending Three Terpenes Boosts Ferric-Reducing Antioxidant Activity in Optimized Mixtures

The research, published on 25 October 2026, used twelve randomized mixture trials, each the mean of three independent repetitions, to map how the proportions of the three terpenes shape the overall antioxidant response.

When tested alone, the three terpenes varied widely in potency. p-cymene showed the strongest ferric-reducing activity, with an EC50 of 123.03 ± 2.05 µg/mL, followed by thymol at 153.16 ± 2.84 µg/mL, while β-ionone was the weakest at 931.46 ± 5.37 µg/mL. Across the twelve mixture trials, FRAP EC50 values ranged from 79.76 to 931.46 µg/mL, indicating that the right blend could outperform even the best single compound.

Statistical analysis of the mixture data identified significant contributions from the linear terms (β1, β2, β3), the binary interactions (β12, β13), and the ternary interaction term (β123). This pattern means that both the individual terpenes and their combined, interaction effects shaped the antioxidant response, rather than the activity being a simple sum of the parts. Examination of 2D and 3D mixture plots suggested that an EC50 of around 79.70 µg/mL could be achieved by combining all three terpenes.

Desirability analysis went further, predicting an optimal FRAP EC50 of 58.23 µg/mL from a mixture containing 17% β-ionone, 42% p-cymene, and 41% thymol, with a global desirability of 99.9%. The authors report that these findings demonstrate that strategic blending of structurally related terpenes can substantially enhance ferric-reducing capacity and provide a framework for developing natural antioxidant formulations. As a laboratory mixture-optimization study, the work establishes predicted formulation performance rather than tested end products, and the reported optimal values are model predictions from the mixture design.

Subject of Research: Mixture optimization of three terpenes to enhance ferric-reducing antioxidant activity

Article Title: Enhancing ferric-reducing antioxidant activity through terpene mixture optimization

Article References: Qasem, A. (2026). Enhancing ferric-reducing antioxidant activity through terpene mixture optimization. Scientific Reports. https://doi.org/10.1038/s41598-026-77654-8

Image Credits: AI Generated

DOI: 10.1038/s41598-026-77654-8

Keywords: terpenes, p-cymene, thymol, β-ionone, antioxidant activity, FRAP, mixture design, desirability analysis, EC50, natural antioxidants, Enhancing, ferric-reducing