Valorization of ‘Rossa di Tropea’ Onion Waste through Green Recovery Techniques of Antioxidant Compounds

The aim of this work was to maximize the recovery bioactive components from an important solid waste derivate Tropea onion processing. To achieve this, three different extractive procedures (conventional for maceration, ultrasound, and microwave-assisted) were employed, using only food-grade extraction solvents such as water ethanol:water (50:50). Solvent, temperature, microwave power, time, their interaction studied principal factors that might affect extractability rates. obtained data suggest hydroalcoholic mixture proved be best each techniques developed at time temperature considered. In particular, results achieved by conventional 60 min 40 °C (total flavonoids content: 25.64 ± 1.40 mg QE g?1 d.w.; total anthocyanins 0.78 0.01 C-3-GLUC d.w.). UHPLC analysis optimally extract revealed phytochemicals recovered quercetin (5322.61 0.32 kg?1) 3-4?-diglucoside (1023.80 0.34 after ultrasound-assisted extraction, respectively. perspective, implementation sustainable, processes recover value-added substances could play a crucial role both in reducing load formulating natural food additives with functional properties, potential direct industrial impact.