Supercritical CO2 Extraction of Narcissus poeticus L. Flowers for the Isolation of Volatile Fragrance Compounds

Cocoa Pod Husks (CPH) and by-product from supercritical CO2 extracted Rosa damascena Mill. (RDCO2) were used as biopreservatives in muffins. Both by-products were rich source of polyphenols: 28.3 ± 0.6 mg/g Dry Weight (DW) and 17.9 ± 0.7 mg/g DW RDCO2 and CPH, respectively, and exhibited potent antioxidant capacity: 449.1 ± 8.5 µmol Trolox Equivalents (TE)/g DW (by ORAC method) and 58.9 ± 2.1 µmol Gallic Acid Equivalents (GAE)/g DW (by HORAC method) for the RDCO2, and 373.8 ± 9.0 µmol TE/g DW (by ORAC) and 36.8 ± 3.8 µmol GAE/g DW (by HORAC) for the CPH. RDCO2 extracts successfully inhibited development of several important pathogenic and saprophytic microorganisms causing microbial spoilage of food systems. The control muffins were good for consumption up to the 17th day, while the products supplemented with RDCO2 and CPH: until 20th day of storage at 22 ± 0.5 °C. The amount of dietary fibers in muffins supplemented with both by-products increased 3 times (8.57 ± 0.12 %) compared to control (2.91 ± 0.12 %) and the polyphenolic compounds increased 2.5 times (from 50.0 ± 0.3 for the control to 185.9 ± 0.6 mg/g DW). For the first time by-product of supercritical CO2 extraction of Rosa damascena Mill. was characterized and used as natural and cheap biopreservative.

The article presents the optimization of supercritical CO2 extraction (SFE-CO2) parameters using response surface methodology (RSM) with central composite design (CCD) in order to produce single variety hop (cv. Ella) extracts with high yield and strong in vitro antioxidant properties. Optimized SFE-CO2 (37 MPa, 43 °C, 80 min) yielded 26.3 g/100 g pellets of lipophilic fraction. This extract was rich in biologically active α- and β-bitter acids (522.8 and 345.0 mg/g extract, respectively), and exerted 1481 mg TE/g extract in vitro oxygen radical absorbance capacity (ORAC). Up to ~3-fold higher extraction yield, antioxidant recovery (389.8 mg TE/g pellets) and exhaustive bitter acid extraction (228.4 mg/g pellets) were achieved under the significantly shorter time compared to the commercially used one-stage SFE-CO2 at 10–15 MPa and 40 °C. Total carotenoid and chlorophyll content was negligible, amounting to <0.04% of the total extract mass. Fruity, herbal, spicy and woody odor of extracts could be attributed to the major identified volatiles, namely β-pinene, β-myrcene, β-humulene, α-humulene, α-selinene and methyl-4-decenoate. Rich in valuable bioactive constituents and flavor compounds, cv. Ella hop SFE-CO2 extracts could find multipurpose applications in food, pharmaceutical, nutraceutical and cosmetics industries.

Precious metals, in particular Pd, have a wide range of applications in industry. Due to their scarcity, precious metals have to be recycled, preferably with green and energy-saving recycling processes. In this article, palladium extraction from an aluminosilicate-supported catalyst, containing about 2 wt% (weight%) of Pd (100% PdO), with supercritical CO2 (scCO2) assisted by complexing polymers is described. Two polymers, p(FDA)SH homopolymer and p(FDA-co-DPPS) copolymer (FDA: 1,1,2,2-tetrahydroperfluorodecyl acrylate; DPPS: 4-(diphenylphosphino)styrene), were tested with regards to their ability to extract palladium. Both polymers showed relatively low extraction conversions of approximately 18% and 30%, respectively. However, the addition of piperidine as activator for p(FDA-co-DPPS) allowed for an increase in the extraction conversion of up to 60%.