RESUMO
This study aimed to compare the effects of two extraction techniques (conventional n-hexane and supercritical CO2) on the oil extraction yields, fatty acids profile, anti-hyaluronidase activity, oxidative stability, and in vitro bioactivities of oils from Sacha Inchi (Plukenetia volubilis). Higher oil extraction yield (99 %) was achieved using the SC-CO2, although similar fatty acids profiles were depicted between both treatments (p < 0.05). The SC-CO2 oil presented higher anti-hyaluronidase (31 %) activity, but lower oxidative stability (5.05 h) compared to the solvent extraction (10 %, and 5.3 h, respectively). In vitro assays further revealed that the best human normal colon cells (FHC) cell viability (100 %), anti-inflammatory (50 % lower NO production), and antioxidant (20 % ROS reduction) activities were consistently observed in both extraction treatments at concentrations of 50 µg/mL and higher. These findings highlight the potential of supercritical CO2 extraction in yielding Sacha Inchi oil with enhanced bioactive properties without the disadvantages of the use of organic solvents extraction.
RESUMO
Croton lechleri, commonly known as Dragon's blood, is a tree cultivated in the northwest Amazon rainforest of Ecuador and Peru. This tree produces a deep red latex which is composed of different natural products such as phenolic compounds, alkaloids, and others. The chemical structures of these natural products found in C. lechleri latex are promising corrosion inhibitors of admiralty brass (AB), due to the number of heteroatoms and π structures. In this work, three different extracts of C. lechleri latex were obtained, characterized phytochemically, and employed as novel green corrosion inhibitors of AB. The corrosion inhibition efficiency (IE%) was determined in an aqueous 0.5 M HCl solution by potentiodynamic polarization (Tafel plots) and electrochemical impedance spectroscopy, measuring current density and charge transfer resistance, respectively. In addition, surface characterization of AB was performed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy techniques. Chloroform alkaloid-rich extracts resulted in IE% of 57% at 50 ppm, attributed to the formation of a layer of organic compounds on the AB surface that hindered the dezincification process. The formulation of corrosion inhibitors from C. lechleri latex allows for the valorization of non-edible natural sources and the diversification of the offer of green corrosion inhibitors for the chemical treatment of heat exchangers.
Assuntos
Cobre/química , Croton/química , Ácido Clorídrico/química , Extratos Vegetais/química , Zinco/química , CorrosãoRESUMO
Lactic acid fermentation increases the bioactive properties of shrimp waste. Astaxanthin is the principal carotenoid present in shrimp waste, which can be found esterified in the liquid fraction (liquor) after its lactic acid fermentation. Supercritical CO2 technology has been proposed as a green alternative to obtain astaxanthin from fermented shrimp waste. This study aimed to optimize astaxanthin extraction by supercritical CO2 technology from fermented liquor of shrimp waste and study bioaccessibility using simulated gastrointestinal digestion (GD) of the optimized extract. A Box-Behnken design with three variables (pressure, temperature, and flow rate) was used to optimize the supercritical CO2 extraction. The optimized CO2 extract was obtained at 300 bar, 60 °C, and 6 mL/min, and the estimated characteristics showed a predictive extraction yield of 11.17%, antioxidant capacity of 1.965 mmol of Trolox equivalent (TE)/g, and astaxanthin concentration of 0.6353 µg/g. The experiment with optimal conditions performed to validate the predicted values showed an extraction yield of 12.62%, an antioxidant capacity of 1.784 mmol TE/g, and an astaxanthin concentration of 0.52 µg/g. The astaxanthin concentration decreased, and the antioxidant capacity of the optimized extract increased during gastrointestinal digestion. In conclusion, our optimized supercritical CO2 process is suitable for obtaining astaxanthin from shrimp by-products after lactic acid fermentation.
Assuntos
Antioxidantes , Penaeidae/química , Animais , Antioxidantes/análise , Antioxidantes/isolamento & purificação , Dióxido de Carbono/química , Fermentação , Resíduos , Xantofilas/análise , Xantofilas/isolamento & purificaçãoRESUMO
Grape seeds are an important byproduct from the grape process. The objective of this work was to evaluate the effect of experimental parameters (temperature and time of pretreatment with ultrasound) to obtain grape seed oil using low pressure (Soxhlet-Sox and Bligh Dyer-BD) and high pressure (supercritical carbon dioxide-SFE) methods. The best condition for pretreatment of samples was 30 min of sonication at 30 °C before extraction by Sox or BD. Ultrasound pretreatment was efficient to increase oil extraction yield by 32.10 (Sox), 20.31 (BD) and 12.54% (SFE), depending on the extraction method used as well as, and certainly influenced the total phenolic concentration in 311 (Sox), 234 (BD), and 184 (SFE)%. Ten fatty acids were identified in the oils, the major ones being 18:2ω-6cis (linoleic 52.39%-63.12%), 16:0 (palmitic 20.22%-26.80%) and 18:0 (stearic 8.52%-13.68%). The highest epicatechin concentration was identified in the BD sample: 30-30 (150.49 ± 5.98mg/kg), which presented a concentration of ≥3 times compared to the control (56.68 ± 1.81mg/kg). Ultrasound pretreatment also contributed positively (56% and 99% increase) in the α-tocopherol content of the SFE: 30-30 and BD: 30-30 samples, respectively. The results indicate that the ultrasound pretreatment is a suitable technology to improve the quality of the oil from the grape seed.
Assuntos
Óleos de Plantas/análise , Vitis/química , Pressão Atmosférica , Cromatografia com Fluido Supercrítico , Ácidos Graxos/análise , Sementes/química , UltrassonografiaRESUMO
Endophytic fungi have been highlight in the production of secondary metabolites with different bioactive properties, such as in the production of the antioxidant compounds. Therefore, the objective of this work was the extraction of the antioxidant compounds from the biomass of Diaporthe schini using supercritical carbon dioxide (CO2) without and with ethanol as cosolvent. The biomass was produced by submerged fermentation and the parameters evaluated in the extraction process were: pressure (150-250 bar), temperature (40-60 ºC) and cosolvent [biomass: cosolvent ratio, 1:0, 1:0.75 and 1:1.5 (w/v)]. Extraction yield, antioxidant activity and chemical composition of the extracts were determined. The highest extraction yield (3.24 wt.%) and the best antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (96.62%) were obtained at 40 ºC, 250 bar and biomass:cosolvent ratio of 1:1.5 (w/v). The chemical compounds 1,4-diaza-2,5-dioxo-3-isobutyl bicyclo[4.3.0]nonane and benzeneethanol identified in GC/MS could be responsible for the antioxidant activity found in this study.
Assuntos
Antioxidantes , Ascomicetos/química , Dióxido de Carbono/química , Etanol/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Solventes/químicaRESUMO
In this work were extracted bioactive compounds from Brassica oleracea var capitata using supercritical CO2 and evaluated the antioxidant potential of the extracts. Five extractions were accomplished to investigate the influence of pressure (10-25 MPa) and temperature (20-60 °C) in the extraction yield, chemical composition and antioxidant potential towards peroxyl, superoxide and hydroxyl radicals. The highest extraction yield was obtained at 60 °C and 25 MPa, which was 0.47 wt% (run 2). In the characterisation of the extracts obtained was possible the identification of sulforaphane and iberin nitrile that present known biological properties. The extracts of all runs presented antioxidant activities towards the three radicals, but the highest activities for all radicals were using the extracts obtained in the run 2. The use of supercritical CO2 extraction to obtain bioactive compounds of B. oleracea var capitata showed to be a promising alternative to conventional extraction methods, since allowed the extraction of compounds with scientific and industrial interest.