SEARCH · Search PubMed

Results for “Extraction and Processing Industry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources

PubMed2003

Membrane-assisted extractive bioconversions.

This chapter summarizes the use of membrane reactors in extractive bioconversions as process integration systems leading to in situ product recovery. Several membrane reactor configurations are analyzed, taking into account the type of bioconversion, biocatalyst type and location (either in the aqueous phase or in the membrane), membrane chemistry and morphology, solvent (extractant) type and its biocompatibility. Modeling of liquid-liquid extractive membrane bioreactors operation is also analyzed considering kinetics and mass-transfer aspects. The chapter includes examples from the authors' laboratory as well as other published in the field. Both enzyme and whole cell-based bioconversions are considered. Relevant aspects related to the solvent (extractant) toxicity and how the membrane could protect the biocatalytic activity are analyzed. Trends in this field are also given.

Bioreactors↗

PubMedDate not supplied

Purchasing population health: aligning financial incentives to improve health outcomes.

OBJECTIVE: To review the concept of population health, including its definition, measurement, and determinants, and to suggest an approach for aligning financial incentives toward this goal. DATA SOURCE, STUDY DESIGN, DATA EXTRACTION: Literature review, policy analysis PRINCIPAL FINDINGS: The article presents the argument that a major reason for our slow progress toward health outcome improvement is that there is no operational definition of population health and that financial incentives are not aligned to this goal. Current attempts at process measures as indicators of quality or outcome are not adequate for the task. It is suggested that some measure of health-adjusted life expectancy be adopted for this purpose, and that integrated delivery systems and other agents responsible for nonmedical determinants be rewarded for improvement in this measure. This will require the development of an investment portfolio across the determinants of health based on relative marginal return to health, with horizontal integration strategies across sectoral boundaries. A 20-year three-phase development strategy is proposed, including components of research and acceptance, integrated health system implementation, and cross-sectoral integration. CONCLUSIONS: The U.S. health care system is a $1 trillion industry without a definition of its product. Until population outcome measures are developed and rewarded for, we will not solve the twenty-first century challenge of maximizing health outcome improvement for the resources available.

Delivery of Health Care, Integrated↗

PubMed1984

Determination of trace elements of Egyptian cane sugar (Naga Hammady factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analyses.

INAA, AAS and ICP-AES techniques are applied to the determination of trace amounts of Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in the stalks of sugar cane plant after extracting juice, raw juice principal (mixed) juice, juice withdrawn from the successive stages of sugar industry, sirup, deposits from evaporators, molasse, A-? and B-sugar and in the soil samples (collected from the field supplying the factories by cane plants) taken from the immediate vicinity of the plant roots at surface, 30 and 60 cm depth. The results obtained are in a good agreement of the safety baselines of using juice as beverage, molasse derivatives (honey, sweets, ...) as diet for common people in the developed countries and in industry (methanol, ethanol, acetone & acetic acid, ...) and sugar sweeting for many purposes (in beverages, desserts, ...). Differences of trace elements concentrations in soil samples may be reasoned to geochemical and biogeochemical fractionation while those in juice may be due to the changes in the environmental conditions, chemical composition and botanic structures. Variations in trace element contents in the products formed during the successive stages of sugar industry may be a result of evaporation, filtration processes, chemical treatments or corrosion of vessels, containers or engines. Trace elements are very important where they are responsible for enzymatic and biochemical reactions, matabolism, health and diseases.

Carbohydrates↗

PubMed2003

Near-infrared spectroscopy for on-line monitoring of lube base oil processes.

Near-infrared (NIR) spectroscopy has been utilized for monitoring the pour point of the lube base oil (LBO) process. Using partial least-squares (PLS) regression, necessary spectral features were successfully extracted and correlated to the reference pour-point data. In a preliminary laboratory feasibility study, it was found that PLS calibration performance was largely governed by the accuracy of the reference pour-point analysis. The same NIR spectroscopic methodology was moved to monitor the pour point continuously in an on-line manner. At this time, the NIR spectrometer was calibrated with the existing on-line pour-point analyzer, which was more accurate. In comparison with the on-line pour-point analyzer, NIR spectroscopy provided faster and more repeatable analytical data. With the help of NIR analysis, LBO process variations during product switch can be detected earlier, and necessary process-control strategy can be applied to improve the process efficiency.

Algorithms↗

PubMed2002

Variations in levels of acid phosphatase present in chicken whole leg meat.

Acid phosphatase (ACP) has been identified as a potential biomarker for endpoint temperature determination in further-processed poultry. Multiple analyses of the same sample for ACP have produced consistent results. The degree of variation in ACP levels present in different production lots has not been identified. This study was conducted utilizing a single flock of broilers. Birds were slaughtered on four separate days (replications), and whole leg, without skin, was homogenized. Proximate composition was analyzed for each replication. Water-soluble proteins were extracted from raw meat and assessed for initial ACP levels. Samples of meat were cooked to an internal temperature of 71.1 C. There were differences (P < 0.05) between replications for both moisture and fat content. When dry fat content was analyzed, no significant differences occurred between replicates. Initial ACP levels were different (P < 0.0001) between replicates (500.33 to 348.97 units of activity/kg). Levels of ACP activity after cooking were also different (P < 0.0001) between replicates (17.61 to 10.82 units of activity/kg). Percentage degradation of activity during cooking was similar (96.98 to 95.89%) between replicates. ACP levels were consistently measured within a replicate. Differences between replicates for both initial and cooked levels indicate a threshold level for determination of thermal endpoint would be difficult to establish. ACP may not be a sensitive measure to estimate the degree of doneness of meat samples in which initial ACP concentration is unknown. Identical raw sample required for such a comparison would be difficult for the processing industry to maintain.

Acid Phosphatase↗

PubMed2001

Herbal nutriceuticals: a primer for dentists and dental hygienists.

Herbs have been in use for centuries to prevent and control disease. In recent history demand by the public for herbal supplements has created a multimillion-dollar industry. Herbal extracts are effective because they interact with specific chemical receptors within the body and are in a pharmacodynamic sense, drugs themselves. A matter for public concern is that herbal supplements are currently independent of regulation by the Federal Drug Administration (FDA). The FDA considers herbal products to be dietary supplements, not drugs. The National Toxicology Program has recently started to examine the composition and standardization of commercial preparations to identify potential health hazards from contaminants or product over use. Many herbal preparations have significant pharmacological effects. The problem that arises for the dental professional is the effect these products have in concert with prescription medications as well as effects on the patient's general response to medication and dental treatment. Drug interactions with the large number of commercially available herbal products can be grouped by the mechanism of most common interactions. These major types of reactions are: (1) alteration of drug metabolizing enzyme activity, (2) interactions with the blood clotting process, and (3) alteration of the inflammatory and immune response. The widespread use of herbal supplements makes it essential that healthcare providers become informed about this aspect of a patient's personal health practices.

Blood Coagulation↗

PubMed2026

Transcriptomic insights into exogenous fatty acid-enhanced halotolerance in Zygosaccharomyces rouxii.

BACKGROUND: High salinity restricts microbial growth during brine-based food fermentation. Although exogenous unsaturated fatty acids improve the salt tolerance of Zygosaccharomyces rouxii, the associated transcriptional mechanisms remain unclear. This study investigated the transcriptomic response of Z. rouxii CGMCC 3791 to palmitoleic acid (C16:1) under high salt conditions. RESULTS: Cells were cultured in yeast extract peptone dextrose (YPD) containing 120 g L-1 NaCl, with or without 20 μg mL-1 C16:1. They were analyzed by RNA sequencing. Principal component analysis clearly separated the two treatments. Using q < 0.05 and |log2 fold change| > 1, 23 differentially expressed genes were identified - three upregulated and 20 downregulated. INO1, MLS1, POX1, MEP2, and SOD5 were among the major responsive genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that peroxisome-associated functions, lipid metabolism, oxidative stress responses, nitrogen utilization, and mitogen-activated protein kinase (MAPK) signaling were the principal C16:1-responsive processes. CONCLUSION: Exogenous C16:1 elicited a focused transcriptional adjustment rather than broad transcriptome-wide reprogramming in salt-stressed Z. rouxii. The results indicated that peroxisome-linked lipid processes and redox regulation were candidate mechanisms underlying fatty-acid-associated halotolerance and provided targets for improving the robustness of high-salt food fermentation. © 2026 Society of Chemical Industry.

Zygosaccharomyces rouxii↗

PubMed2006

Proposal of a sequential treatment methodology for the safe reuse of oil sludge-contaminated soil.

In this study sequential steps were used to treat and immobilize oil constituents of an oil sludge-contaminated soil. Initially, the contaminated soil was oxidized by a Fenton type reaction (13 wt% for H(2)O(2); 10mM for Fe(2+)). The oxidative treatment period of 80 h was carried out under three different pH conditions: 20 h at pH 6.5, 20 h at pH 4.5, and 40 h at pH 3.0. The oxidized contaminated sample (3 kg) was stabilized and solidified for 2h with clay (1 kg) and lime (2 kg). Finally, this mixture was solidified by sand (2 kg) and Portland cement (4 kg). In order to evaluate the efficiency of different processes to treat and immobilize oil contaminants of the oil sludge-contaminated soil, leachability and solubility tests were performed and extracts were analyzed according to the current Brazilian waste regulations. Results showed that the Fenton oxidative process was partially efficient in degrading the oil contaminants in the soil, since residual concentrations were found for the PAH and BTEX compounds. Leachability tests showed that clay-lime stabilization/solidification followed by Portland cement stabilization/solidification was efficient in immobilizing the recalcitrant and hazardous constituents of the contaminated soil. These two steps stabilization/solidification processes are necessary to enhance environmental protection (minimal leachability) and to render final product economically profitable. The treated waste is safe enough to be used on environmental applications, like roadbeds blocks.

Aluminum Silicates↗

PubMed2001

Anaerobic treatment of brewery wastewater with an internal membrane bioreactor.

Anaerobic treatment is growing very popular these days because of low sludge production compared to activated sludge processes. The drawback of the process is the risk of sludge washout, especially when the formation of granular sludge is not expected. By using an internal anaerobic bioreactor this problem can be overcome. A lab scale internal anaerobic membrane bioreactor was operated at SEGHERSbetter technology for Water N.V. to which brewery wastewater was fed (COD=2300 mg/l). Hollow fibres were inserted into the anaerobic bioreactor, from which the effluent was extracted by underpressure. The COD-removal was excellent and very constant at a value of 95%. No suspended solids were present in the effluent. The membrane permeability stabilised at relatively low value of 18 l/m2.h.bar due to an irreversible adhesion of constituents in the bioreactor. No growth of biomass was found during two months of operation. Inocculated granular sludge fell apart into loose flocs within several weeks of the startup, not affecting biological performance. The internal anaerobic membrane bioreactor is a promising new area within the field of wastewater treatment. It is expected that this process will have an important future.

Anaerobiosis↗

PubMed2007

Fermentation process tracking through enhanced spectral calibration modeling.

The FDA process analytical technology (PAT) initiative will materialize in a significant increase in the number of installations of spectroscopic instrumentation. However, to attain the greatest benefit from the data generated, there is a need for calibration procedures that extract the maximum information content. For example, in fermentation processes, the interpretation of the resulting spectra is challenging as a consequence of the large number of wavelengths recorded, the underlying correlation structure that is evident between the wavelengths and the impact of the measurement environment. Approaches to the development of calibration models have been based on the application of partial least squares (PLS) either to the full spectral signature or to a subset of wavelengths. This paper presents a new approach to calibration modeling that combines a wavelength selection procedure, spectral window selection (SWS), where windows of wavelengths are automatically selected which are subsequently used as the basis of the calibration model. However, due to the non-uniqueness of the windows selected when the algorithm is executed repeatedly, multiple models are constructed and these are then combined using stacking thereby increasing the robustness of the final calibration model. The methodology is applied to data generated during the monitoring of broth concentrations in an industrial fermentation process from on-line near-infrared (NIR) and mid-infrared (MIR) spectrometers. It is shown that the proposed calibration modeling procedure outperforms traditional calibration procedures, as well as enabling the identification of the critical regions of the spectra with regard to the fermentation process.

Calibration↗

PubMed2002

River systems as providers of goods and services: a basis for comparing desired and undesired effects of large dam projects.

In developing countries, large dam projects continue to be launched, primarily to secure a time-stable fresh-water supply and to generate hydropower. Meanwhile, calls for environmentally sustainable development put pressure on the dam-building industry to integrate ecological concerns in project planning and decision-making. Such integration requires environmental impact statements (EISs) that can communicate the societal implications of the ecological effects in terms that are understandable and useful to planners and decision-makers. The purpose of this study is to develop a basic framework for assessing the societal implications of the river ecological effects expected of a proposed large dam project. The aim is to facilitate a comparison of desired and potential undesired effects on-site and downstream. The study involves two main tasks: to identify key river goods and services that a river system may provide, and to analyze how the implementation of a large dam project may alter the on-site capacity and downstream potentials to derive river goods and services from the river system. Three river goods and six river services are identified. River goods are defined as extractable partly man-made products and river services as naturally sustained processes. By four main types of flow manipulations, a large dam project improves the on-site capacity to derive desired river goods, but simultaneously threatens the provision of desirable river goods and services downstream. However, by adjusting the site, design, and operational schedule of the proposed dam project, undesirable effects on river goods and services can be minimized.

Conservation of Natural Resources↗

PubMed2002

Toxicity testing and chemical analyses of recycled fibre-based paper for food contact.

Food-contact materials, including paper, have to comply with a basic set of criteria concerning safety. This means that paper for food contact should not give rise to migration of components, which can endanger human health. The objectives of this pilot study were, first, to compare paper of different qualities as food-contact materials and to perform a preliminary evaluation of their suitability, from a safety point of view, and, second, to evaluate the use of different in vitro toxicity tests for screening of paper and board. Paper produced from three different categories of recycled fibres (B-D) and a raw material produced from virgin fibres (A) were obtained from industry, and extracts were examined by chemical analyses and diverse in vitro toxicity test systems. The products tested were either based on different raw materials or different treatments were applied. Paper category B was made from 40% virgin fibres, 40% unprinted cuttings from newspapers, and 20% de-inked newspapers and magazines. Paper categories C and D were based on newspapers and magazines. However, paper D was de-inked, whereas C was not. To identify constituents of the papers with a potential to migrate into foodstuff, samples of the paper products were extracted with either 99% ethanol or water. Potential migrants in the extracts were identified and semiquantified by GC-IR-MS or GC-HRMS. In parallel to the chemical analyses, a battery of four different in vitro toxicity tests with different endpoints were applied to the same extracts. (1) a cytotoxicity test using normal human skin fibroblasts. The test was based on measurements of the reduction of resazurin to resorufin by cellular redox processes and used as a screening test for acute or general toxicity; (2) a Salmonella/microsome assay (Ames test) as a screening test for mutagenic and potentially carcinogenic compounds; (3) a recombinant yeast cell bioassay as a screening test for compounds with oestrogenic activity; (4) an aryl hydrocarbon (Ah)-receptor assay (CALUX assay) as a screening test for compounds with dioxin-like activity. In addition, the papers were testedfor microbial content and, in general, the microbiological load was quite low. The following microorganisms were counted and identified on both surface and homogenized pulp samples: the total number of aerobic bacteria, the number of aerobic and anaerobic spore formers, the number of Bacillus cereus/thuringiensis, and the number of yeast and moulds. The chemical analyses showed a significantly higher amount and different composition pattern of chemicals extracted with ethanol compared with water. Analyses of the ethanol extracts showed a distinctly smaller number and lower concentrations of chemicals in extracts prepared from sample A compared with extracts of samples B-D. The compounds identified in B-D were similar, but the amounts were lower in B compared with C and D. In accordance with the chemical analyses, the water extracts were less cytotoxic than the ethanol extracts. The extract prepared from virgin fibres was less cytotoxic than the extracts prepared from paper made from recycled fibres, and extracts prepared from C was the most cytotoxic. None of the extracts showed mutagenic activity. No conclusion about the oestrogenic activity could be made, because all extracts were cytotoxic to the test organism (yeast cells). Ethanol extracts of A and B showed a negligible positive response in the Ah-receptor assay at the highest nontoxic concentration, whereas C and D showed a more pronounced effect with C being the most potent. A comparable weak effect of water extracts of samples B-D was observed, too. However, the active compound(s) was not identified by chemical analyses.

Biological Assay↗

PubMedDate not supplied

Industrial-scale production of inactivated poliovirus vaccine prepared by culture of Vero cells on microcarrier.

In 1980, the authors reported preliminary results of large-scale production of inactivated poliovirus vaccine in which virus was produced in Vero cell culture on a microcarrier. For this first stage of development, 150-liter tanks were used. The virus is now produced in 1,000-liter tanks. The main point concerning the quality of Vero cells, namely the absence of tumorigenicity, has been demonstrated, qualifying them for use in the Institut M erieux cell bank. The purity of the cell line has also been determined by checking for the absence of bacteria, fungi, mycoplasmas, and viruses. The search for oncornavirus and for reverse transcriptase activity was carried out, and the results were negative but are not described in this paper. The quality of the purification process was checked by a search for residual cellular DNA in concentrated, purified, and inactivated vaccine. With use of a molecular hybridization procedure, a specific probe was prepared to detect approximately 50 pg of DNA per filter. The preliminary results show that the purification procedure fulfills the World Health Organization's requirements. T1 oligonucleotide mapping has also shown the identity of poliovirus RNA extracted from virus grown on Vero cells and that from primary monkey kidney cells. These data have led to the awarding of a license by the French government to the Institut M erieux for production of this new, reassessed, inactivated poliovirus vaccine.

Animals↗

PubMed2002

Heavy metal contamination of the soils used for stocking raw materials in the former ILVA iron-steel industrial plant of Bagnoli (southern Italy).

The total contents and the chemical and mineralogical forms of the metals Fe, Al, Cu, Co, Cr, Pb, Zn, Ni and Mn in the horizons of a soil profile, representative of an area devoted to stocking raw materials in the dismantled iron-steel industrial plant of ILVA of Bagnoli (Naples), were studied by physical and chemical methods. The geological setting of the study area is the result of volcanic activity in the Phlegrean Fields, a group of polygenic volcanoes to the west of Naples, which give rise to the parent soil material. Soil morphology appeared to be strongly disturbed by the occurrence and stratification of materials used in the industrial process. Fine sediments illuviation down the profile resulted in the occurrence of silt and clay coatings. The total contents of Cu, Co, Cr, Pb, Zn and Ni, in the whole soil samples, especially in the surface layers, were above the regulatory levels (Cu 120, Co 20, Cr 150, Pb 100, Zn 150, Ni 120 mg kg(-1)) stated by the Italian Ministry of Environment for soils in public, private and residential areas, and below the levels (Cu 600, Co 250, Cr 800, Pb 1000, Zn 1500, Ni 500 mg kg(-1)) outlined for soils and subsoils of industrial and commercial areas (Gazzetta Ufficiale della Repubblica Italiana, 1999). Speciation of heavy metals and the determination of the different chemical pools in the fraction < 2 mm identified the large presence of elements trapped in the mineralogical structure of oxides and silicates and occluded in easily reducible manganese or iron oxides. A constant amount of Cu was associated with organic compounds. A significant amount of Zn (> 20%) was extracted in diluted acetic acid solution, indicating that the element was present in a more readily and potentially available form. In the clay fraction (< 2 microm) heavy metals were associated with both amorphous and crystalline iron forms. The presence of iron-rich clay coatings was evident in the illuvial pores of deeper horizons. Enrichment in Cu, Co, Cr and Zn of the coatings was observed. Possible translocation of metals down through the soil profile mainly bound to fine particles of relatively inert forms of iron is hypothesised. The dispersion in water of the clay fraction resulted in an average percentage dispersion of approximately 20% with a peak of 41.7% at 68-72 cm depth. Magnetite, goethite, hematite, calcite and quartz mixed with K-feldspars, clynopyroxenes and mica occurred in the coarse sand fractions (2-0.2 mm) of the soil samples from all the surface horizons. Talcum and goethite together with clay minerals at 1.4 nm, kaolinite and illite were found in the clays (< 2 microm).

Environmental Monitoring↗

PubMed2003

Inhibition of nitrobenzene-induced DNA and hemoglobin adductions by dietary constituents.

Nitrobenzene (NB), a widely used industrial chemical, is a likely human carcinogen. Many dietary constituents can suppress the DNA-adduction, acting as the inhibitors of cancer. In this study, we investigated the inhibitory effects of vitamin C (VC), vitamin E (VE), tea polyphenols (TP), garlic squeeze, curcumin, and grapestone extract on NB-DNA and NB-hemoglobin (Hb) adductions in mice using an ultrasensitive method of accelerator mass spectrometry (AMS) with 14C-labelled nitrobenzene. All of these dietary constituents showed their inhibitory effects on DNA or Hb adduction. VC, VE, TP and grapestone extract could efficaciously inhibit the adductions by 33-50%, and all of these six agents could inhibit Hb adduction by 30-64%. We also investigated resveratrol, curcumin, VC and VE as inhibitors of NB-DNA adduction in vitro using liquid scintillation counting technique. These agents in the presence of NADPH and S9 components also pronouncedly blocked DNA adduction in a dose-dependent profile. Our study suggests that these seven constituents may interrupt the process of NB-induced chemical carcinogenesis.

Animals↗

PubMed2003

Rapid classification of basil chemotypes by various vibrational spectroscopy methods.

The potential of vibrational spectroscopy methods (attenuated total reflectance/Fourier-transform-infrared (ATR/FT-IR), FT-Raman and near infrared (NIR) spectroscopy) for the identification and quantification of valuable as well as carcinogenic substances in different basil chemotypes is described. It is shown that all main volatile components occurring in different basil accessions can be reliably determined in the isolated essential oils or solvent extracts but also in the air-dried herbs. While NIR data can be interpreted only by chemometric methods, IR and Raman spectra present characteristic key bands of the individual volatiles; therefore, in the latter case, a discrimination of basil chemotypes is frequently possible without applying chemometric algorithms. NIR calibrations are successfully established for various terpenoids and phenylpropanoids; on the basis of these data, the content of the two carcinogenic compounds methyleugenol (range: 2-235 microg/100 g) and estragole (range: 34-138 microg/100 g) can be reliably predicted in air-dried basil leaves (R (2) (coefficient of determination) = 0.951; SECV (standard error of cross validation) = 19.1 microg/100 g and R (2) = 0.890; SECV = 12.8 microg/100 g, respectively). The described methods were found to be very useful tools for the efficient selection of special basil single plants, adapted to the new demands set by the legislator and the consumer. Furthermore, they can be applied in industry to very easily control the purifying, blending, and redistilling processes of basil oil.

Calibration↗

PubMed1977

Analysis of the polycyclic aromatic hydrocarbon content of airborne particulate pollutants in a Søderberg paste plant.

A method of enrichment and separation of polycyclic aromatic hydrocarbons (PAH) in air samples is described. Airborne particulate samples from the work atmosphere of a Soderberg carbon-paste plant were collected on glass fiber and Acropor filters using high volume samplers. The filters were Soxhlet-extracted using cyclohexane and extractable matter was subject to a liquid/liquid separation. The PAH-fraction was concentrated and separated on a gas chromatographic system with the possibility of mass spectrometric identification. More than 40 PAH compounds and some heterocyclic compounds having from 3-6 rings have been separated and identified. Quantitative determinations show that some of the PAH-components are 2-3 decades more abundant than recently reported data from urban air samples. The results are presented as a PAH-profile. It is suggested that the PAH-profile may be a characteristic of the process involved. Furthermore, the profile has a potential use of the profile in evaluating potentially hazardous risk of the PAH's.

Air Pollutants↗

PubMed2006

Supercritical CO2 extraction of oilseeds: review of kinetic and equilibrium models.

Mass transfer models on supercritical carbon dioxide (SC-CO2) extraction of vegetable oils are reviewed, that may facilitate the scale-up of laboratory data for industrial design purposes. Reviewed mechanisms of oil transport within the solid matrix include the desorption from the solid, the formation of a shrinking core of condensed oil in a non-adsorbing porous matrix, and diffusion in a homogenous medium. Analyzed simplificat ions of a general mass transfer model include external control of mass transfer rates, internal control of mass transfer rates, consideration of a linear driving force, and steady state approximations, among others. More complex two-stage models, and critical comparisons of some of the proposed models are also included. Trends for the external mass transfer coefficient and effective diffusivity in the solid matrix from studies on SC-CO2 extraction of oil from vegetable substrates are thoroughly discussed and contrasted with those obtained using simpler model systems. The possible effect of the axial dispersion on the rate of extraction is also discussed. Finally, the high-pressure vegetable oil-CO2 phase equilibrium is discussed in connection with its influence on the mass transfer process. Special emphasis is given to the role of the solid matrix on high-pressure phase equilibrium.

Carbon Dioxide↗