The use of deep eutectic solvents and pulsed electric field as a pre-treatment for ultrasound-assisted extraction of bioactive compounds from tomato peel

Tomato peel waste is a valuable source of bioactive compounds such as lycopene, β-carotene and polyphenols, which can be sustainably extracted using deep eutectic solvents (DES). In this study, pulsed electric field (PEF) pre-treatment combined with ultrasound-assisted extraction was applied to optimize recovery. The highest lycopene concentration (282.55 mg/mL) and antioxidant activity (50.24 %) were obtained at 6 min extraction and 2 μs pulse duration. Under the same conditions, total polyphenols reached 0.995 mg/mL, while a slightly higher value (1.025 mg/mL) with similar antioxidant activity (50.27 %) was obtained in treatment of 9 min with 0.5 μs pulse duration. The maximum β-carotene content (50.65 mg/mL) was obtained in treatment of 6 min and 2 μs pulse duration. Antioxidant activity strongly correlated with lycopene and polyphenol contents, while colour parameters were influenced by the concentration of bioactive compounds, particularly carotenoids, and by treatment duration. Increasing treatment time and pulse duration raised the specific energy input but caused partial degradation of carotenoids and polyphenols, confirming that mild PEF conditions enhance extraction efficiency while preserving compound stability. These results demonstrate the potential of DES combined with optimized PEF parameters as a sustainable approach for producing tomato-based products with improved nutritional and functional properties. • Tomato peel is rich in compounds of industrial interest, carotenoids and polyphenols. • PEF enhanced extraction of bioactive components from tomato peel. • DES is an environmentally friendly alternative to organic solvents. • DES present low toxicity and ensure a higher product yield. • PEF and DES are employed in green and sustainable extraction techniques.