Husk, a by-product of rice processing, is often considered waste, but it is a resource that is still underutilised, rich in interesting nutritional and functional properties. Several scientific studies have highlighted its content of bioactive compounds, including oil rich in unsaturated fatty acids, phytosterols, tocopherols and γ-oryzanol, for use as new food ingredients.
In a recent study carried out by a group of Italian researchers (Tenuta et al., 2025), conventional extraction techniques (maceration and Soxhlet) were compared with innovative technologies (ultrasound and supercritical CO2), with the aim of increasing yield and preserving the quality of the extracted compounds. In particular, supercritical CO 2 extraction has a higher yield (11.35%) than traditional methods (8.35%), producing an oil enriched in tocopherols and γ-oryzanol. To assess its potential as a functional ingredient, the latter was subjected to tests for antioxidant capacity (DPPH) and oxidative stability (isothermal calorimetry).
The results show that the oil extracted using supercritical CO 2 has the highest radical scavenging activity and better oxidative stability.
In summary, the comparison between the technologies shows that innovative methods are more sustainable and effective in adding value to rice husks as a source of new food ingredients.
Bibliographic references: M.C. Tenuta et al., National Conference on Food Science and Technology, Bologna, June 9-10, 2025, 87.
