Senise Red Pepper (Capsicum annuum L.) Wastes as Source of Rich Capsanthin Extracts by Supercritical CO2 Extraction

Abstract

The valorization of agro-industrial by-products represents a key strategy for promoting sustainable resource use and recovering high-value bioactive compounds. This study investigated the extraction of carotenoids from processing residues of Capsicum annuum L. cv Senise, a sweet pepper with Protected Geographical Indication (PGI) status, using supercritical CO2 extraction (SC-CO2). Experiments were conducted under nine pressure–temperature combinations (250–450 bar; 40–60 °C) for 60 min, and the results were compared with those obtained by conventional solvent extraction. The extraction yield ranged from 21.5 to 23.5 g/kgDW, with the highest total carotenoid content (386 mg/kgDW) achieved at 450 bar and 60 °C (SFE9), corresponding to a 70.2% recovery relative to the solvent method. HPLC analysis identified capsanthin (5.88 mg/g) as the predominant carotenoid in this extract, followed by zeaxanthin (2.16 mg/g), lutein (0.71 mg/g), β-cryptoxanthin (0.70 mg/g), β-carotene (0.58 mg/g) and capsorubin (0.38 mg/g). Overall, the results demonstrate that the green extraction of Senise pepper waste offers a sustainable approach to obtaining valuable natural pigments.