Antioxidant Properties of Phenolic Compounds in Oilseeds

Oilseeds such as rapeseed, mustard, flax, hemp and canola are rich repositories of phenolic compounds, a class of secondary metabolites characterised by one or more aromatic rings bearing hydroxyl substituents. These compounds include sinapic acid derivatives (for example sinapine, sinapoyl glucose and canolol), flavonoids and various hydroxycinnamic acids. Within the seed, concentrations are unevenly distributed between hulls, cotyledons and press-cakes, with cotyledons often exhibiting the highest levels. Phenolics mitigate oxidative deterioration in lipid matrices by scavenging free radicals, chelating pro-oxidant metal ions and quenching singlet oxygen, thereby extending shelf life and preserving nutritional quality. Beyond technological applications, oilseed phenolics confer health benefits through modulation of oxidative stress and inflammation in vivo. Recent advances have centred on optimising extraction techniques, understanding the impact of thermal and mechanical processing on antioxidant potency, and exploring chemical modifications to enhance lipophilicity and incorporation into lipid systems. The valorisation of by-products such as defatted seed cakes is emerging as a sustainable route to recover high-value phenolic fractions. Collectively, these developments underscore the global significance of oilseed phenolics for food security, functional nutrition and zero-waste biorefinery strategies.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Antioxidant Properties of Phenolic Compounds in Oilseeds publication trend

The graph below shows the total number of articles in antioxidant properties of phenolic compounds in oilseeds across all publications each year (not limited to Nature Index journals).

Technical terms

Phenolic compounds: Aromatic secondary metabolites containing one or more hydroxyl groups directly bonded to an aromatic ring, responsible for antioxidant activity in plants.

Sinapic acid derivatives: Hydroxycinnamic acid compounds such as sinapine and sinapoyl glucose, abundant in Brassica seeds.

Canolol: 4-vinyl-2,6-dimethoxyphenol formed by thermal decarboxylation of sinapic acid, with potent radical-scavenging properties.

DPPH assay: A method that measures the ability of antioxidants to quench the stable 2,2-diphenyl-1-picrylhydrazyl radical, expressed as percentage inhibition or IC₅₀.

FRAP assay: Ferric reducing antioxidant power, an assay quantifying the capacity of antioxidants to reduce Fe³⁺ to Fe²⁺ under acidic conditions.

Ultrasonication: The application of high-frequency sound waves to enhance mass transfer and disrupt cell structures, facilitating rapid extraction of bioactives.

References

1. Antioxidative Polyphenols from Defatted Oilseed Cakes: Effect of Solvents. Antioxidants (2014).
2. Seed-Roasting Process Affects Oxidative Stability of Cold-Pressed Oils. Antioxidants (2019).
3. Antioxidant Capacity of Rapeseed Extracts Obtained by Conventional and Ultrasound‐Assisted Extraction. Journal of the American Oil Chemists' Society (2014).
4. Alkyl Caffeates Improve the Antioxidant Activity, Antitumor Property and Oxidation Stability of Edible Oil. PLOS ONE (2014).
5. Antioxidant Potential of the Extracts, Fractions and Oils Derived from Oilseeds. Antioxidants (2013).
6. Endogenous Phenolics in Hulls and Cotyledons of Mustard and Canola: A Comparative Study on Its Sinapates and Antioxidant Capacity. Antioxidants (2014).