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1.
Industrially, thermal treatments are extensively used to inactivate microorganisms in foods. However, the demand for new pasteurization methods with reduced impact on the nutritional content and overall food quality is increasing. In this context, this study investigated and compared the effect of supercritical carbon dioxide (SC-CO2) alone or in combination with high power ultrasound (HPU) on both the natural microbial flora (mesophilic, lactic acid bacteria and yeast and molds) of coconut water and the pathogenic Gram-negative bacteria Salmonella enterica inoculated in the product. Inactivation kinetics were obtained at 12 MPa, by means of batch apparatuses, at different times (from 1 up to 60 min) and temperature conditions (from 25 up to 45 °C). The synergistic effect of SC-CO2 + HPU was evident and a higher microbial reduction was achieved compared to SC-CO2 alone: at 12 MPa and 40 °C about 5 log reductions were achieved for natural microbial flora in about 15 min while about 30 min were needed for SC-CO2 treatment. The storage study highlighted that SC-CO2 treated coconut water resulted microbiologically unstable and showed heavy regrowth phenomena during the storage, while, a full shelf life of 4 weeks was assured for SC-CO2 + HPU treated samples. 相似文献
2.
This work explored the potential of subcritical liquids and supercritical carbon dioxide (CO2) in the recovery of extracts containing phenolic compounds, antioxidants and anthocyanins from residues of blueberry (Vaccinium myrtillus L.) processing. Supercritical CO2 and pressurized liquids are alternatives to the use of toxic organic solvents or extraction methods that apply high temperatures. Blueberry is the fruit with the highest antioxidant and polyphenol content, which is present in both peel and pulp. In the extraction with pressurized liquids (PLE), water, ethanol and acetone were used at different proportions, with temperature, pressure and solvent flow rate kept constant at 40 °C, 20 MPa and 10 ml/min, respectively. The extracts were analyzed and the highest antioxidant activities and phenolic contents were found in the extracts obtained with pure ethanol and ethanol + water. The highest concentrations of anthocyanins were recovered with acidified water as solvent. In supercritical fluid extraction (SFE) with CO2, water, acidified water, and ethanol were used as modifiers, and the best condition for all functional components evaluated was SFE with 90% CO2, 5% water, and 5% ethanol. Sixteen anthocyanins were identified and quantified by ultra performance liquid chromatography (UPLC). 相似文献
3.
Ethanol modified supercritical carbon dioxide (SC-CO2) extraction of flavonoids from Momordica charantia L. fruits and its antioxidant activity were performed. The influences of parameters such as temperature, extraction time and pressure on the yield of flavonoids were investigated. The antioxidant activities of flavonoids were assessed by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and β-carotene bleaching test. The experimental data obtained indicated that pressure, temperature and time had significant effect on the extraction yield. The optimum extraction conditions, determined by the 3D response surface and contour plots derived from the mathematical models, were as follows: extraction temperature 46 °C, pressure 33.4 MPa, and extraction time 53.2 min. Under these conditions, the experimental value was 15.47 mg/g, which was well matched with value predicted by the model. The antioxidant activity of flavonoids obtained by ethanol modified SC-CO2 extraction method had higher antioxidant activity than the flavonoids extracted by conventional solvent extraction (CSE) method. The DPPH radical-scavenging ability of flavonoids obtained by ethanol modified SC-CO2 extraction method reached to 96.14 ± 1.02%, equivalent to the clearance rate of ascorbic acid at 1.2 mg/mL. Results indicated that ethanol modified SC-CO2 extraction was a suitable approach for the selective extraction of flavonoids from M. charantia L. 相似文献
4.
Supercritical carbon dioxide (SC-CO2) extraction of grape marc was studied using water (W) and ethanol (EtOH) as co-solvent at 15% (w/w), 100 and 200 MPa, and 313.15, 323.15 and 333.15 K to analyze their influence upon total phenols of the extracts. The overall extraction curves were determined and suggested 10 MPa and 313.15 K as the best operating conditions for SC-CO2 + 15%W extraction, and 10 MPa and 333.15 K for SC-CO2 + 15% EtOH. The phenolic yields obtained were 63.4 g/kg of extract for SC-CO2 + 15% W and 38.8 g/kg of extract for SC-CO2 + 15% EtOH. An alternative method combining Sc-CO2 + 15% W extraction, followed by SC-CO2 + 15% EtOH was tested. This procedure provided the best results allowing to obtain the highest phenolic yield (68.0 g/kg of extract), phenol content (733.6 mg GAE/100 g DM), proanthocyanidins concentration (572.8 mg catechin/100 g DM) and antioxidant activity (2649.6 mg α-tocopherol/100 g DM). SC-CO2 methods were compared with methanol extraction. 相似文献
5.
Carob pulp kibbles, a by-product of carob been gum production, was studied as a source of bioactive agents. Firstly, the carob kibbles were submitted to an aqueous extraction to extract sugars, and supercritical fluid extraction (SFE) was applied to the solid residue of that aqueous extraction, by using compressed carbon dioxide (SC-CO2) as the solvent and a mixture of ethanol and water (80:20, v/v) as a co-solvent. Pressure and temperature were studied in the ranges 15–22 MPa, and 40–70 °C. Particle diameter, and co-solvent percentage in ranges of 0.27–1.07 mm, and 0–12.4%, respectively, were also studied, as well as the flow rate of SC-CO2 between 0.28 and 0.85 kg h−1, corresponding, respectively, to 0.0062 and 0.0210 cm s−1 of superficial velocity. The extracts were characterised in terms of antioxidant capacity by DPPH method, and total phenolics content by the Folin–Ciocalteu method. The central composite non-factorial design was used to optimise the extraction conditions, using the Statistica, version 6 software (Statsoft). The best results, in terms of yield and antioxidant capacity, were found at 22 MPa, 40 °C, 0.27 mm particle size, about 12.4% of co-solvent and a flow rate of 0.29 kg h−1 of SC-CO2. The phenolics profile of the extracts obtained at these conditions was qualitatively evaluated by HPLC-DAD. The solid residue of the supercritical extraction was also studied showing to be a dietary fiber, which can be compared to Caromax™, a carob fiber commercialised by Nutrinova Inc. 相似文献
6.
The combined effect of supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) on the inactivation kinetics of Escherichia coli, Saccharomyces cerevisiae and pectin-methyl esterase (PME) in orange juice was studied in order to select models that can predict their inactivation behaviour based on process parameters. Experiments were performed at different temperatures (31–41 °C, 225 bar) and pressures (100–350 bar, 36 °C). The inactivation rate of E. coli, S. cerevisiae and PME increased with pressure and temperature during SC-CO2 + HPU treatments. The SC-CO2 + HPU inactivation kinetics of E. coli, S. cerevisiae and PME were represented by models that included temperature, pressure and treatment time as variables, based on the Biphasic, the Peleg Type B, and the fractional models, respectively. The HPU-assisted SC-CO2 batch system permits the use of mild process conditions and treatment times that can be even shorter than those of continuous SC-CO2 systems. 相似文献
7.
This work reports the use of Melia azedarach L. extracts obtained from supercritical carbon dioxide extraction (SC-CO2) as an insecticidal agent against fall armyworm (Spodoptera frugiperda). For this purpose, SC-CO2 extractions were performed, varying the pressure (150–250 bar), temperature (313–333 K), sample particle size and extraction time. Secondary metabolites from the classes of coumarins, sterols and terpenes were identified in the extracts, with the triterpene melianone being the major constituent. For the biological activity tests, diets were prepared with different SC-CO2 extract concentrations (100, 500, 1000 and 5000 mg/kg) and offered to S. frugiperda (Lepidoptera: Noctuidae). The results indicated that mortality increased with increasing extract concentrations with 50% mortality (LC50) at a concentration of 376.74 mg/kg and reaching 100% mortality at 5000 mg/kg. The inhibition of insect growth was observed at higher concentrations due to the antifeedant action of the extract. At the lowest extract concentration (100 mg/kg), ingestion caused low pupal viability and adults presenting morphological deformities, which thus indicated a chronic toxicity effect. 相似文献
8.
The aim of the present study was to determine an effective sterilization method for safe handling and recycle-reuse of clinical solid waste materials. Supercritical fluid carbon dioxide (SC-CO2) was applied in the inactivation of gram positive Staphylococcus aureus (S. aureus) and gram negative Serratia marcencens (S. marcescens) in clinical solid waste. The colony forming activity of the bacteria was completely lost at pressures 10–40 MPa, temperatures 35–80 °C and treatment period between 5 and 120 min. An increase in pressure at constant temperature and vice versa with the increasing treatment time enhanced the SC-CO2 inactivation efficiency. The inactivation process was illustrated by the modified Gompertz equation. The SC-CO2 inactivation of bacteria was compared with the steam autoclaved bacteria. Regrowth of the bacteria was observed in the autoclaved sample while no re-growth was detected in the SC-CO2 treated clinical solid waste. Results from SEM image analysis, cellular protein and enzymatic activity of untreated, autoclaved and SC-CO2 treated S. marcescens and S. aureus cells confirmed that SC-CO2 is an effective sterilization method. 相似文献
9.
Go-Woon Jung Hee-Moon Kang Byung-Soo Chun 《Journal of Industrial and Engineering Chemistry》2012,18(1):360-363
Supercritical carbon dioxide (SC-CO2) and soxhlet extraction using was carried out to extract oil from wheat bran oil. For SC-CO2, the pressure and temperature were ranging from 10 to 30 MPa and 313.15–333.15 K. The extraction was performed in a semi batch process with a CO2 flow rate of 26.81 g/min for 2 h. Wheat bran oil was characterized to investigate the quality. Acid value (AV) and peroxide value (POV) were higher in hexane extracted oil compared to SC-CO2 extracted oil. Induction period was measured by rancimat test. The oil obtained by SC-CO2 extraction had higher capability to delay the oxidation by surrounding environment. The DPPH radical scavenging activity was also measured. The SC-CO2 extracted oil showed higher radical scavenging activity compared to hexane extracted oil. 相似文献
10.
Jun-Ho Yun Hye-Youn Lee A.K.M. Asaduzzaman Byung-Soo Chun 《Journal of Industrial and Engineering Chemistry》2013,19(2):686-691
Lecithin was isolated from squid viscera residues after supercritical carbon dioxide (SC-CO2) extraction at 25 MPa and 45 °C. The particle formation of squid lecithin with biodegradable polymer, polyethylene glycol (PEG) was performed by PGSS using SC-CO2 in a thermostatted stirred vessel. By applying different temperatures (40 and 50 °C) and pressures (20–30 MPa), conditions were optimized. Two nozzles of different diameters (250 and 300 μm) were used for PGSS and the reaction time was 1 h. The average diameter of the particles obtained by PGSS at different conditions was about 0.74–1.62 μm. The lowest average size of lecithin particle with PEG was found by the highest SC-CO2 density conditions with the stirring speed of 400 rpm and nozzle size of 250 μm. The inclusion of lecithin in PEG was quantified by HPLC. Acid value and peroxide value was measured after micronization of lecithin. 相似文献
11.
This work aims to study supercritical anti-solvent (SAS) micronization of lutein derived from marigold flowers. Lutein solution in dichloromethane (DCM) or ethanol was atomized into the stream of supercritical carbon dioxide (SC-CO2) through a concentric nozzle in a pressurized vessel. The effects of pressure and SC-CO2 flow rate on morphology, mean particle size (MPS) and particle size distribution (PSD) were investigated. The reduction in lutein MPS from 202.3 μm of unprocessed lutein to 1.58 μm and 902 nm could be achieved by SAS micronization using DCM and ethanol, respectively. In both solvent systems, no significant effects of pressure and SC-CO2 flow rate on particle morphology were observed. However, pressure was found to have a significant effect on MPS and PSDs of lutein particles. 相似文献
12.
Supercritical carbon dioxide (SC-CO2) extraction of lipid from Scenedesmus sp. for biodiesel production was investigated and compared to conventional extraction methods. The effect of biomass pre-treatment prior to extraction and extracting conditions, namely pressure in the range of 200–500 bar, temperatures in the range of 35–65 °C and CO2 flow rate in the range of 1.38–4.02 g min−1, on SC-CO2 extraction yield and quality of lipid were investigated. Three levels full factorial design of experiments and response surface methodology was used to model the system. A second order polynomial model was developed and used to predict the optimum conditions. Scaling up to a laboratory larger scale was also tested. The results indicated that SC-CO2 extraction was superior to other extraction techniques, but exhibited significant variations in yield with changes in operating parameters. In the developed model, it was found that the linear and quadratic terms of the temperature, as well as the interaction with pressure had a significant effect on lipid yield; whereas, their effect on lipid quality was insignificant. The best operating conditions, in the tested range, were 53 °C, 500 bar and 1.9 g min−1, in which lipid extraction yield of 7.41% (dry weight basis) was obtained. Negligible differences were observed when the fatty acid composition of SC-CO2 extracted lipid was compared to that extracted by the conventional methods. At the optimum conditions, SC-CO2 extraction was successfully scaled-up by eight-folds and the extracted lipid yield dropped by 16%. 相似文献
13.
Zhanqun Hou Yuanyuan Zheng Yanxiang Gao Xuan Liu Fang Yuan Guangmin Liu 《Food and Bioproducts Processing》2010,88(2-3):298-304
Supercritical CO2 (SC-CO2) extraction was applied to remove lipid and cholesterol from freeze-dried goat placenta. A response surface methodology (RSM) was employed to optimize the extraction parameters. The effects of pressure, temperature, flow rate of CO2 and extraction time on the yields of lipid and cholesterol were investigated. Response surface analysis showed that the data were adequately fitted to second-order polynomial model. The independent variables, quadratics of pressure and extraction time, and the interaction between pressure and temperature had significant effects on the yields of lipid and cholesterol, respectively. The optimum parameters within the experimental range of the variables were 34.6 MPa, 35.3 °C, 29.1 min with a CO2 flow rate of 18.2 L/h. Under such condition, the yields of lipid and cholesterol were predicted to be 21.02% and 8.46 mg/g, respectively. Furthermore, the removal efficiency of cholesterol by SC-CO2 was higher than those achieved by Soxhlet and Folch extraction methods. 相似文献
14.
This work aims to study supercritical anti-solvent micronization of marigold derived purified lutein that was dissolved in the mixture of hexane and ethyl acetate (70:30 v/v), the solvent used as the mobile phase for chromatographic purification. The results show significant effect of pressure on the morphology of micronized lutein particles. The increase in lutein initial concentration from 1.5 mg/ml to 3.2 mg/ml and the increase in SC-CO2 flow rate from 15 ml/min to 25 ml/min show no significant effects on the morphology of lutein particles. However, the reduction of mean particle size from about 2 μm to 0.8 μm was observed by increasing SC-CO2 flow rate. The X-ray diffraction patterns of the micronized lutein particles show apparent amorphous nature, while the Fourier transform infrared spectroscopy results show that no chemical structural changes occurred. Moreover, the solubility of the micronized lutein particles in aqueous solution was found to increase significantly from being almost insoluble to having approximately 20% solubility 相似文献
15.
Byeong Sub Kwak Byung-Hyun Choi Mi-Jung Ji Sun-Min Park Misook Kang 《Journal of Industrial and Engineering Chemistry》2012,18(1):11-15
Nanometer-sized nickel oxide (NiO) particles were synthesized by thermal reactions with nickel (II) carbonate as a metal-containing precursor and four solvents: water, ethanol, butanol, and acetone. The optimal reaction conditions to obtain spherical NiO were determined to be the acetone solvent, nickel carbonate precursor, and a reaction temperature and time of 200 °C and 48 h, respectively. TEM images revealed perfectly spherical NiO nanoparticles of size ranging from 2.0 to 10.0 nm in the acetone solvent. The reaction mechanism for the formation of the NiO nanoparticles is proposed based on a pathway of chelated Ni complex during crystal growth. Although metallic Ni was also formed from reactions using the two alcoholic solvents, the Ni(OH)2 structure remained in the water solvent after thermal treatment. 相似文献
16.
Coupling supercritical CO2 (SC-CO2) extraction with membrane separation leads to energy savings by recycling CO2 at supercritical state while separating extract components. However, high pressure operating conditions may cause physicochemical and morphological changes in polymer membranes, which in turn can adversely affect membrane performance. In this study, the effect of different flux (50 and 200 kg/m2 h), temperature (40 and 80 °C) and time (0–8 h) levels were investigated at 120 bar on two commercial reverse osmosis membranes, AK and SG using contact angle, ATR-FTIR and FE-SEM measurements. Contact angle of AK increased substantially with high flux and high temperature processing unlike SG. The peaks assigned to N–H and carbonyl groups at 1541, 1609 and 1663 cm−1 showed the highest decrease in absorbance with high flux processing while high temperature was more effective on O–H groups between 2700 and 3700 cm−1. AK membrane exhibited the formation of bead-like structures at different processing times and conditions. The effect of SC-CO2 processing on the membranes varied depending on their chemical structure, which is important to understand for further process development. 相似文献
17.
In this study, the essential oil of aerial parts of a species of a plant called Smyrnium cordifolium Boiss (SCB) was extracted by supercritical CO2. The essence was analyzed by the method of GC/MS. Design of experiments was carried out with response surface methodology by Minitab 16 software to optimize four operating variables of supercritical carbon dioxide (SC-CO2) extraction (pressure, temperature, CO2 flow rate and extraction dynamic time). This is the first report announcing optimization of the operation of supercritical extraction of SCB in laboratorial conditions. Optimizing process was done to achieve maximum yield extraction. Independent variables were dynamic time (td), pressure (P), temperature (T) and flow rate of SC-CO2 (Q) in the range of 30–150 min, 10–30 MPa, 40–60 °C and 0.5–1.7 ml/min, respectively. The experimental optimal recovery of essential oil (0.8431, w/w%) was obtained at 13.43 MPa, 40 °C, 150 min (dynamic) and 1.7 ml/min (CO2 flow rate). 相似文献
18.
M.S. Liza R. Abdul Rahman B. Mandana S. Jinap A. Rahmat I.S.M. Zaidul A. Hamid 《Food and Bioproducts Processing》2010,88(2-3):319-326
The bioactive flavonoid compounds of Strobilanthes crispus (Pecah Kaca) leaves obtained by using supercritical carbon dioxide (SC-CO2) extraction were investigated and the obtained crude extract yields were compared in order to select the best operation parameters. Since carbon dioxide is a non-polar solvent, ethanol was used as co-solvent to increase the polarity of the fluid. The studied parameters were pressure (100, 150 and 200 bar), temperature (40, 50 and 60 °C) and dynamic extraction time (40, 60 and 80 min). The optimum extraction condition occurred at 200 bar, 50 °C and 60 min. Based on the mean value, pressure had dominant effect on the extraction yield. Apart from the optimum SFE conditions two other conditions namely at minimum (100 bar, 40 °C, 40 min) and maximum (200 bar, 60 °C, 80 min) levels of each studied parameters as control runs were analyzed by HPLC to determine the major bioactive flavonoid compounds from S. crispus. Under the optimum conditions eight flavonoid compounds were identified; they were (+)-catechin, (?)-epicatechin, rutin, myricetin, luteolin, apigenin, naringenin and kaempferol. 相似文献
19.
Nowadays due to wide usages of supercritical fluids (SCFs) technology in different industrial fields, thermal conductivity estimation of carbon dioxide is so significant. In this study, a new correlation for the prediction of supercritical carbon dioxide (SC-CO2) thermal conductivity based 600 data points from the literature is proposed. The simple correlation is function of density and temperature. The proposed SC-CO2 thermal conductivity correlation has better performance (lower AARE%) and higher thermal conductivity prediction ability at wider range of temperature from 290 to 800 K and density between 1 and 1200 kg/m3 respect to Jarrahian et al. and Bahadori et al. thermal conductivity models. 相似文献
20.
Adsorption kinetics of four volatile organic compounds (VOCs) (acetone, toluene, n-hexane and n-decane) on activated carbon under supercritical carbon dioxide (scCO2) conditions was studied. Breakthrough curve measurements of VOCs in scCO2 were performed with a fixed bed method for activated carbon (ca. mean particles diameter: 100 μm, specific surface area: 1300 m2/g and mean pore diameter: 0.687 nm, respectively). The measured breakthrough curves could be correlated with a kinetic model by using only one fitting parameter (effective diffusion coefficient in pore) within 10% of average relative deviation. The determined effective diffusion coefficient decreased with decreasing temperatures and increasing pressures at all conditions. Additionally, a generalized model of the determined effective diffusion coefficients was developed, and the proposed model could satisfactorily describe temperature and pressure dependence at all VOCs conditions. 相似文献