High-pressure biorefining of ora-pro-nobis (Pereskia aculeata)

Ora-pro-nobis (OPN) is an unconventional food plant used in some Brazilian regions in traditional culinary. A combination of high-pressure extraction processes was used, following the biorefinery concept, to value this underestimated raw material. A sequence of extractions was performed, with solvents of increasing polarity: supercritical fluid extraction (SFE-CO2), pressurized liquid extraction using ethanol (PLE-ethanol) and water (PLE-water). Soxhlet and buffer maceration were used for comparison. Extraction yield, antioxidant capacity, phenolics and soluble protein contents were evaluated. Samples recovered by water had better antioxidant capacity, while ethanol samples presented higher phenolic content. The process combination improved yield, antioxidant potential, phenolics and soluble protein recovery, especially combining SFE + PLE-ethanol + PLEwater. Overall, 13 phenolics were identified, mainly flavonoids and organic acids, known for its antioxidant and biological activities, confirming the extracts high value-added. Thus, downstream process combination for OPN leaves enabled the recovery of high value-added products following the biorefinery concept.