Extraction of compounds from Moringa oleifera leaves using supercritical CO₂ plus ethanol as a cosolvent

Abstract

Extracts of compounds fromMoringa oleifera leaves were obtained by supercritical extraction with CO 2 using ethanol as a cosolvent (scCO 2 + EtOH). The experimental conditions were investigated by varying temperature (35-80 C), pressure (15-25 MPa), and mass ratio between ethanol and raw material. The phenolic acids (gallic, vanillic, and p-coumaric acids) and flavonoids (catechin) were identified in all extracts, except for the extract obtained without the cosolvent. The main compounds by GC-MS were 1-triacontanol, nonacosane, heptacosane, phytol, γ-tocopherol, and α-tocopherol. Extracts obtained at 35 C showed the highest values of total phenolic compounds, DPPH, and FRAP, however, the lowest extraction yield. The central point extraction conditions (60 C and 20 MPa) had the best-combined results for yield (4.4%), total phenolic compounds (24 ± 1 mg GAE/g), DPPH (77 ± 2 μmol Trolox/g), FRAP (265 ± 9 μmol Trolox/g) and the presence of bioactive compounds. Practical ApplicationsSupercritical fluid extraction with CO 2 is a clean technology that employs low temperatures, producing high-quality extracts. Moringa oleifera leaf extracts showed different compositions according to the experimental conditions evaluated. The use of ethanol as a cosolvent and high temperatures positively influenced the extraction yield. All extracts showed antioxidant potential. Catechin, gallic, vanillic, and pcoumaric acids were the main phenolic compounds. The extract obtained at the central point condition had better antioxidant potential, yield, and bioactive compounds.

Moringa oleifera L. Screening: SFE-CO2 Optimisation and Chemical Composition of Seed, Leaf, and Root Extracts as Potential Cosmetic Ingredients

“…The fatty acids group, with a total relative composition of 29.51-31.83%, include the linolenic (18.85-20.17%), palmitic (4.50-5.28%), and linoleic acids (3.28-3.47%). The higher fatty acid content in Mo leaf SFE-CO 2 extracts obtained in this work compared to the other studies [25,36] may be a consequence of extraction conditions, environmental effects, and agriculture practices. The high unsaturated fatty acid content (linolenic and linoleic acids) makes the Mo leaf extracts a potential alternative for skin hydration and a protective barrier against pollution effects, mainly due to their antioxidant and antimicrobial activities [17].…”

“…Hydrocarbons are also present with a total relative composition of 34.46-36.73%, with the most relevant compound being nonacosane (17.74-22.89%). Other recent works on Mo SFE-CO 2 extraction reported the presence of the nonacosane hydrocarbon varying from 19.10% [25] to 60.06% [36]. Nonacosane belongs to the waxy compound family located on the leaves' surface, and shows reduced mass transfer resistance to the supercritical CO 2 [36].…”

“…The extraction ability of CO 2 , a non-polar solvent, can also be enhanced using a co-solvent such as ethanol. The mixture modifies the solvent characteristics and improves the polar molecules' affinity [25].…”

“…Parameters such as plant material granulometry, extraction time, CO 2 flow rate, and use of co-solvent are frequently considered in optimisation processes [26,27]. Recognised as a GRAS (Generally Recognised as Safe) process by the United States FDA (Food and Drug Administration) and European Union statements, SFE-CO 2 has been previously applied to obtain Mo seed [26][27][28][29][30][31][32][33][34] and leaf extracts [25,35,36]. Moreover, statistical methodologies, namely the response surface methodology (RSM), were used to improve the extraction of the target compounds.…”

Moringa oleifera Lam Leaf Extract Stimulates NRF2 and Attenuates ARV-Induced Toxicity in Human Liver Cells (HepG2)

“…Polyphenols found in MO are gallic acid, catechin, epicatechin, p-coumaric acid, ferulic acid, vanillin, caffeic acid, protocatechuic acid, cinnamic acid, procyanidins, aurantiamide acetate, quercetin glycoside, quercetin rhamnoglycoside, pterygospermin, and chlorogenic acid. Lastly, MO leaves are rich in minerals such as calcium, potassium, zinc, magnesium, iron, and copper, and vitamins including vitamins A, B, pyridoxine, nicotinic acid, and folic acid, C, D, and E [ 35 , 36 , 37 , 38 , 39 ]. Therefore, MO leaves provide powerful antioxidative benefits [ 40 , 41 ], free radical scavenging [ 42 ], anticancer [ 43 , 44 ], hepatoprotective [ 45 ], anti-proliferative, anti-mutagenic, promotes carbohydrate metabolism [ 46 ], and repairs DNA [ 43 ] thus validating the traditional claims.…”