Evaluation of the Effect of Different Co-Solvent Mixtures on the Supercritical CO2 Extraction of the Phenolic Compounds Present in Moringa oleifera Lam. Leaves

Abstract

Supercritical fluid extraction (SFE), using CO2, is a novel, sustainable and very efficient technique for the recovery of highly apolar compounds. However, the recovery of phenolic compounds requires the use of different co-solvent combinations such as water and ethanol to enhance the recovery of these compounds through the optimization of a number of variables. In this sense, the effect of pressure (100, 150 and 200 bar), temperature (50, 65 and 80 °C), extraction time (30, 60, 90, 120, 150 and 180 min) and the effect of the different percentages of ethanol and water as co-solvents on the composition and phenolic content of moringa leaf extracts were evaluated. Six major flavonoids were identified by ultra-high-performance liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer (UHPLC-Q-ToF-MS). Pressure and temperature had a significant effect on the phenolic composition of the extracts, as well as on their concentrations. The highest concentration of total flavonoids compounds (TFCs) was obtained by using a mixture of CO2 and water of 50:50 (v/v) at 100 bar, at 65 °C after a 120 min extraction time that produced a concentration of 11.66 mg ± 0.02 mg TFC g−1 sample, which corresponds to 89.0% of the total flavonoids of the sample, obtained by exhaustive extraction.

Extraction of Bioactive Compounds from Prestonia mollis Leaves and Their Impregnation into Polylactic Acid Using High-Pressure Technologies: Potential for Biomedical Application

“…Another study described the impregnation of PLA filaments with mango leaf extract. In this case, the best impregnation conditions were registered at 100 bar and 55 • C [30]. These results agree with those established in this work.…”

“…leaves using ESE have identified the presence of some flavanoids among which we should highlight quercetin derivates as quercetin 3-O-glucoside, quercetin malonyl glucoside, quercetin acetyl glucoside, kaempferol 3-Oglucoside and kaempferol malonyl glucoside. Not all the conditions tested extracted all the compounds, quercetin 3-O-glucoside, quercetin malonyl glucoside and kaempferol malonyl glucoside being the most representative ones and those that were recovered under every pressure and temperature configuration tested [30].…”

“…For the ESE, a higher proportion of CO 2 (50% v/v of the total solvent flow) was employed. All conditions were chosen based on the results previously obtained when using other raw materials [30]. The total yields obtained were calculated as the ratio of the total dry extract mass divided by the mass of the raw material, and the results were expressed as a percentage according to Equation (1), where m d is the mass of the dry extract, and m l is the initial mass of the leaves.…”

Ultrasound-Assisted Extraction of Isoquercetin from Ephedra alata (Decne): Optimization Using Response Surface Methodology and In Vitro Bioactivities

“…The addition of formic acid as a cosolvent can enhance the ISQ release into the solvent by improving the contact with the solid. As a result, the yield surface can be increased [ 36 ]. Figure 3 c shows an interaction between ultrasonic power (X4) and ultrasonic temperature (X2).…”