Irradiation Effects on Antioxidant and Phytochemical Properties

Irradiation has emerged as a versatile tool in the processing of foods and natural products, serving both to ensure microbial safety and to modulate the composition and activity of bioactive compounds. By exposing plant matrices to controlled doses of ionising radiation—most commonly gamma rays or electron beams—researchers have observed alterations in the abundance, structure and extractability of phenolic and flavonoid constituents. In many cases, moderate doses enhance total phenolic content and free-radical scavenging capacity, while higher doses may induce partial degradation of sensitive molecules or yield novel derivatives. These changes are highly dependent on the plant species, the tissue or extract under study and the radiation parameters. Globally significant applications range from extending the shelf life of spices and seeds to improving the functional attributes of medicinal herbs and fermented foods.

Research from Nature Portfolio

Radiation has been shown to molecularly transform existing natural products by introducing new functional groups and altering electronic properties. In one study, ionising radiation converted an established non-steroidal scaffold into a hydroxymethylated derivative with markedly increased bioactivity. The newly generated compound exhibited superior inhibition of pro-inflammatory mediators, including nitric oxide and prostaglandin E₂, and down-regulated key enzymes such as cyclooxygenase-2 and inducible nitric oxide synthase in activated macrophages. This work illustrates how irradiation can serve not only as a decontamination technology but also as a means to generate unique phytochemical analogues with enhanced pharmacological potential.

Irradiation Effects on Antioxidant and Phytochemical Properties publication trend

The graph below shows the total number of articles in irradiation effects on antioxidant and phytochemical properties across all publications each year (not limited to Nature Index journals).

Technical terms

Ionising radiation: High-energy photons or particles (e.g. gamma rays, electron beams) capable of inducing chemical changes by generating reactive species.

Phytochemicals: Plant-derived secondary metabolites such as phenolics, flavonoids and terpenoids, often associated with health-promoting effects.

Antioxidant activity: The capacity of a compound or extract to neutralise free radicals or inhibit oxidative processes, commonly measured by assays such as DPPH or ferric reducing power.

Kilogray (kGy): A unit of absorbed radiation dose equal to one thousand grays, where one gray represents the absorption of one joule of radiation energy per kilogram of matter.

References

1. Novel aminopyridazine derivative of minaprine modified by radiolysis presents potent anti-inflammatory effects in LPS-stimulated RAW 264.7 and DH82 macrophage cells. Scientific Reports (2023).
2. Changes in Phytochemical Compounds and Antioxidant Activity of Two Irradiated Sorghum (Sorghum bicolor (L.) Monech) Cultivars during the Fermentation and Cooking of Traditional Sudanese Asida. Fermentation (2022).
3. Validation of γ‐radiation and their effect on phenolic compounds, antioxidant activity, and microbial load of fennel (Foeniculum vulgare) seeds and cinnamon (Cinnamomum verum) sticks. Food Science & Nutrition (2023).
4. Chemical compositions and biological activities of the essential oils from gamma irradiated celery (Apium graveolens L.) seeds. Notulae Botanicae Horti Agrobotanici Cluj-Napoca (2020).