Pulsed electric field aided nutrition, enhancement of bioactive contents, and antioxidant potentials in underutilized stinging nettle (Urtica spp.) leaves

Stinging nettle (Urtica spp.) is a nutrient-dense, underutilized leafy plant rich in bioactive compounds and increasingly recognized for its nutritional and nutraceutical potential. Conventional processing methods, however, often compromise its bioactive content and functional properties, suggesting the need for innovative non-thermal technologies. Pulsed electric field (PEF) treatment has emerged as a processing alternative for enhancing nutrient extraction and preserving sensitive compounds. This study investigated the effects of PEF (1–3 kV/cm) on proximate composition, bioactive compounds, antioxidant activity, and pigment contents of rehydrated leaves of Urtica dioica and U. simensis. The results showed that PEF significantly improved crude fiber, fat, protein, and ash contents, as well as total phenolics, flavonoids, and antioxidant activity, while reducing chlorophyll and carotenoids levels. The highest enhancements were observed at 3 kV/cm, indicating that increasing electric field strength amplifies cellular disintegration and facilitates the releasing of bioactive constituents. Pigment degradation resulted in reduced leaf greenness and noticeable overall color change, implying a potential degreening effect of PEF for product development. These results demonstrate that PEF can enhance the nutritional and functional quality of stinging nettle leaves more effectively than conventional thermal methods. By overcoming the limitations of existing processing methods, this technology offers a potential approach for valorizing underutilized Urtica species in functional foods and nutraceutical applications. Incorporating PEF-treated stinging nettle into food systems could provide sustainable, health-promoting products with improved visual appeal and bioactive content, highlighting the strong potential of this underutilized plant for advancing human nutrition and functional food development.