Valorisation of Salicornia ramosissima biowaste by a green approach – An optimizing study using response surface methodology

The purpose of this study was to optimize the extraction of antioxidants from Salicornia ramosissima by-product through Response Surface Methodology (RSM). The impacts of time (10–60 min) and temperature (40–80 °C) in total phenolic content (TPC) and antioxidant/antiradical activity were assessed. The optimal extract was attained at the binomial 80 °C/10 min and characterized regarding phenolic composition, pigments quantification, radicals quenching capacity, anti-acetylcholinesterase (AChE) activity, and cell viability effects. The optimal extract was characterized by low carotenoids content (8.15 μg/g on dry weight (dw)) and high amounts of hydroxycinnamic acid derivatives (23.12 mg/g dw). A remarkable scavenging efficiency was observed, particularly for HOCl (IC50 = 27.61 μg/mL) and ONOO− (IC50 = 47.32 μg/mL). No adverse effects were detected on HaCaT and HFF-1 viability up to 1000 μg/mL. Additionally, the neuroprotective properties of the optimal extract were demonstrated by AChE inhibition (32.34% at 1000 μg/mL). This study encourages the sustainable recovery of antioxidants from the undervalued biowaste of S. ramosissima as a new raw material for different industries.