Sequential green extractions based on supercritical carbon dioxide and pressurized ethanol for the recovery of lipids and phenolics from Pachira aquatica seeds

Pachira aquatica Aubl. (munguba) seeds represent a rich source of lipids and biocompounds with potential for sustainable exploitation. This work evaluated the feasibility of using supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) to obtain a lipid-rich fraction and extracts rich in biocompounds from munguba seeds. The SFE at 30 MPa/60 degrees C/120 min was the best condition for munguba seed oil (MSO) extraction (52 g 100 g(-1)), providing 95% extraction efficiency compared to Soxhlet with n-hexane. The MSO was composed mainly of palmitic (76.93%), oleic (9.66%), and linoleic (8.15%) fatty acids. Differential Scanning Calorimetry (DSC) showed that the SFE affects the crystallization and melting patterns of MSO, which presents a solid-state below 35 degrees C, regardless of the extraction conditions used. Thermogravimetric analysis showed high thermal stability for MSO (up to 249 degrees C), associated with palmitic acid's high content. Scanning Electron Microscopy (SEM) showed wrinkled, globular, and irregular structures on the defatted munguba seed cake from SFE. These morphological conditions helped obtain PLE-extracts with a significant content of total phenolic compounds ranging from 53.66 to 350.29 mg GAE 100 g(-1). The extracts also presented in vitro antioxidant activity measured by chemical (ferric reducing antioxidant power - FRAP of 2.04-28.41 mM Fe2+ 100 g(-1); inhibition of DPPH between 8.45 and 61.58%), and biological-based (inhibition of lipid peroxidation from 25.47 to 49.45%) methods. This sequential process based on non-toxic solvents is a high yield alternative to recover the rich oil and the phenolic fractions from munguba seeds. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study evaluated the feasibility of using supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) to obtain a lipid-rich fraction and extracts rich in biocompounds from Pachira aquatica Aubl. (munguba) seeds. The results showed that the sequential process using non-toxic solvents is a high yield alternative to recover the rich oil and the phenolic fractions from munguba seeds.