Solventless extraction methods for immature fruits: Evaluation of their antioxidant and cytoprotective activities.

In this study, extraction of immature fruits using an environmentally friendly pressurized hot water extraction (PHWE) method was compared with the traditional reflux method. Extracts were tested for their polyphenol content using the Folin-Ciocalteu assay and for their antioxidant activity using the oxygen radical absorbance capacity (ORAC) assay. The highest amount of polyphenol was extracted from grape (stem) using PHWE at 100°C, or reflux extraction. This was followed by reflux extraction of grape (fruit). The results were similar for the ORAC assay. All samples extracted using PHWE at 100°C showed cytoprotective activity against H2O2-induced oxidative stress in Crandell-Reese feline kidney (CRFK) cells. This study demonstrated that beneficial compounds can be extracted from immature fruits without the use of organic solvents. The utilization of beneficial compounds present in immature fruits can also contribute to the reduction in agriculture waste generated.

Surfactant-Assisted Pressurized Liquid Extraction at Room Temperature for Radix glycyrrhizae by a New Class of Surfactants.

A laboratory-assembled surfactant-assisted pressurized liquid extraction system at room temperature was used for the extraction of glycyrrhizin (GLY) in Radix glycyrrhizae. Environmentally friendly saccharide fatty acid ester such as glucose oleic acid ester is proposed to replace chemical-based surfactants. As the chemical properties of the surfactant obtained were unknown initially, lipase-catalyzed synthesis and liquid chromatography with tandem mass spectrometry were used to ascertain the identity. Surfactant-assisted pressurized liquid extraction (PLE) was carried out dynamically and the extraction efficiencies of the proposed method using different concentration of glucose oleic acid ester were compared with sonication using an organic solvent (ethanol/water, 70:30). The extraction efficiencies of GLY in Radix glycyrrhizae using surfactant-assisted PLE was observed to be higher compared with sonication. The method precision was found to vary from 1.3 to 5.1% (relative standard deviation, RSD, n= 6) on different days. The new method demonstrated the possibility for the extraction to be carried out at room temperature for the production of botanical extracts.

Determination of gastrodin and vanillyl alcohol in Gastrodia elata Blume by pressurized liquid extraction at room temperature.

Pressurized liquid extraction (PLE) at room temperature with a laboratory-assembled system was applied for the extraction of gastrodin (GA) and vanillyl alcohol (VA) in Gastrodia elata Blume. The proposed system setup for this current work was simpler as no heating and backpressure regulator was required. Extraction with PLE was carried out dynamically at a flow rate of 1.5 mL/min, at room temperature, under an applied pressure of 10-20 bars with an extraction time of 40-50 min. The extraction efficiencies of the proposed method using 20% aqueous ethanol were compared with heating under reflux using organic solvents such as methanol and ethanol/water (20:80) for different batches of medicinal plant materials. For the determination of GA and VA in G. elata Blume, the extraction efficiencies of PLE at room temperature were observed to be comparable with heating under reflux. The method precision was found to vary from 1.6 to 8.6% (RSD, n = 6) on different days. The marker compounds present in the various medicinal plant extracts were determined by gradient elution HPLC and HPLC/MS/MS. Our work demonstrated the possibility of implementation of PLE at room temperature and the advantages of minimizing the use of organic solvents in the extraction process.

Evaluation of surfactant assisted pressurized liquid extraction for the determination of glycyrrhizin and ephedrine in medicinal plants.

Surfactant assisted pressurized liquid extraction (PLE) with a laboratory made system was applied for the extraction of glycyrrhizin in radix glycyrrhizae/liquorice and ephedrine in Ephedra sinica. The proposed system set-up for this current work was simpler as no heating and back pressure regulator was required. Extraction with surfactant assisted PLE was carried out dynamically at a flow of 1.5 mL min(-1), at room temperature, under an applied pressure of 10-20 bar with an extraction time of 45-50 min. The extraction efficiencies of the proposed method using surfactants such as sodium dodecyl sulfate (SDS) and Triton X-100 were compared with sonication using organic solvent for different batches of medicinal plants materials. For the determination of glycyrrhizin in R. glycyrrhizae, the extraction efficiencies of surfactant assisted PLE with SDS and Triton X-100 was observed to be comparable with sonication. The method precision was found to vary from 1.6 to 2.6% (R.S.D., n=6) on different days. For ephedrine in E. sinica, surfactant assisted PLE with SDS was found to give higher extraction efficiencies compared to Triton X-100. The overall method precision for surfactant assisted PLE with SDS for ephedrine in E. sinica was found to vary from 1.5 to 4.1% (R.S.D., n=6) on different days. The marker compounds present in the various medicinal plant extracts were determined by gradient elution HPLC. Our data showed the possibility of PLE at room temperature and the advantages of eliminating the use of organic solvents in the extraction process.