Results for “Extraction and Processing Industry” — Page 49

PubMed2002

Enhanced bio-manufacturing through advanced multivariate statistical technologies.

The paper describes the interrogation of data, from a reaction vessel producing an active pharmaceutical ingredient (API), using advanced multivariate statistical techniques. Due to the limited number of batches available, data augmentation was used to increase the number of batches thereby enabling the extraction of more subtle process behaviour from the data. A second methodology investigated was that of multi-group modelling. This allowed between cluster variability to be removed, thus allowing attention to focus on within process variability. The paper describes how the different approaches enabled the realisation of a better understanding of the factors causing the onset of an impurity formation to be obtained as well demonstrating the power of multivariate statistical data analysis techniques to provide an enhanced understanding of the process.

Artifacts↗

PubMed2003

Microalgae mediated photoproduction of beta-carotene in aqueous-organic two phase systems.

Improving productivity is a usual requirement for most biotechnological processes, and the utilisation of two-phase aqueous organic systems has proved to be an effective way to improve the productivity of poorly water-soluble or toxic compounds. The high hydrophobicity of beta-carotene, which is highly demanded by the pharma and agrofood industry, makes it a good candidate for aqueous/organic biphasic photoproduction. In the present work we have investigated the viability of a two-phase system for the production of beta-carotene by the marine microalgae Dunaliella salina using decane as organic phase. Decane, with a logP(octanol) value of 5.6, showed no toxicity to Dunaliella cells for more than 72 h, and its ability for beta-carotene extraction is acceptable. Transferring Dunaliella cells from standard to carotenogenic conditions caused inhibition of chlorophyll production and induced a strong synthesis of beta-carotene. The two-phase aqueous/decane system was stable and beta-carotene content of the cells was increasing during 4-days. About 8% of the total carotenoids produced were excreted and extracted into the decane phase.

Adaptation, Physiological↗

PubMedDate not supplied

Optimization of ectoine synthesis through fed-batch fermentation of Brevibacterium epidermis.

A production process for ectoine has been developed, using Brevibacterium epidermis DSM20659 as the producer strain. First, the optimal conditions for intracellular synthesis of ectoine were determined. The size of the intracellular ectoine pool is shown to be dependent on the external salt concentration, type of carbon source, and yeast extract concentration. Under the optimized conditions of 1 M NaCl, 50 g/L monosodium glutamate, and 2.5 g/L yeast extract, a maximum concentration of intracellular ectoine of 0.9 g/L was obtained in shake flask cultures. After optimizing the batch fermentation parameters of temperature, pH, agitation, and aeration, the yield could be further increased by applying the fed-batch fermentation principle in 1.5- to 2-L fermentors. Glutamate and yeast extract were fed to the bacterial cells such that the total glutamate concentration in the broth remained constant. A total yield of 8 g ectoine/L fermentation broth was obtained with a productivity of 2 g ectoine/L/day. After the bacterial cells were harvested from the culture broth, the ectoine was recovered from them by a two-step extraction with water and ethanol. Crystallization of the product was obtained after concentration of the extract via evaporation under reduced pressure. After this downstream process, 55% of the ectoine produced in the fermentor could be crystallized in four fractions. The first fractions were of very high purity (98%). This production process can compete with other described production processes for ectoine in productivity and simplicity. Further advantages are the relatively low amounts of NaCl needed and the absence of hydroxyectoine, often a byproduct, in the final product.

Air↗

PubMed2005

Predicting inhibitory drug-drug interactions and evaluating drug interaction reports using inhibition constants.

OBJECTIVE: To review the use of inhibitory constants (Ki) determined from in vitro experiments in the prediction of the significance of inhibitory drug-drug interactions (DDIs). DATA SOURCES: Searches of MEDLINE (1966-August 2004) and manual review of journals, conference proceedings, reference textbooks, and Web sites were performed using the key search terms cytochrome P450, drug-drug interaction, inhibition constant, and Ki. STUDY SELECTION AND DATA EXTRACTION: All articles identified from the data sources were evaluated, and information deemed relevant was included for this review. DATA SYNTHESIS: The cytochrome P450 isoenzymes factor prominently in the explanation of numerous DDIs. Although the regulation of these enzymes by one drug can affect the pharmacokinetics of other drugs, the consequences may not necessarily be significant either in terms of pharmacokinetic or clinical outcomes. Yet, many DDI monographs originate as unconfirmed case reports that implicate the influence of one drug on the CYP-mediated metabolism of another, and these often uncorroborated mechanisms can eventually become regarded as dogma. One consequence of this process is the over-prediction of potentially important DDIs. The pharmaceutical industry, Food and Drug Administration, and pharmaceutical scientists have developed a strategy for predicting the significance of inhibitory DDIs at the earliest possible stages of drug development based on a new chemical entity's Ki value, determined in vitro. CONCLUSIONS: We suggest that the use of Ki values of drugs purported to behave as CYP inhibitors be incorporated in the assessment of case reports that ascribe DDIs to inhibition of metabolism of one drug by another.

Area Under Curve↗

PubMed1985

Genetic toxicology in the food industry.

In vitro testing of food products for mutagenic activity presents particular problems, especially in connection with the administration of the test material to the assay system, the possible interference of food components with the genetic end-point used for the assay, the presence in foods of various factors that may modify mutagenic activity, the identification of appropriate negative or positive controls and the avoidance of artefactual mutagen formation during the preparation of test samples. Ideally mutagenicity testing requires in vivo studies (although these too have particular problems when applied to foods) but, at present, in vitro tests provide the only practical means of screening large numbers of food samples or modifying factors and of assessing food-processing techniques. The tests can be carried out on model systems (e.g. amino acid/sugar mixtures), on isolated and purified constituents of foods, on fractionated solvent extracts or on whole-food homogenates subjected to digestion procedures. However, to determine genotoxic risk from foodstuffs, quantitative data from mammalian in vivo tests and from human consumption and metabolism studies are also required.

Animals↗

PubMed2004

Simultaneous determination of the acid/base antihypertensive drugs celiprolol, bisoprolol and irbesartan in human plasma by liquid chromatography.

A simple, rapid method for the simultaneous determination of cardiovascular drugs: celiprolol, bisoprolol and irbesartan in human plasma is described. The two main features of the proposed method deal first, with a simultaneous solid phase extraction of weakly basic beta-blockers derivatives and irbesartan which exhibit weak acidic properties; second with an absorbance monitoring using diode array detection in order to insure an improved selectivity. The separation is performed on a C(18) Kromasil 4.6 mm x 150 mm column using a linear gradient to achieve an entire separation of the four species in less than 20 min. The full analytical validation is performed according to guidance for industry for bioanalytical method validation. Linearity of the response was demonstrated for each drug for a range fulfilling the reported plasma levels, that is 10-500, 5-250 and 20-1000 ng l(-1) for celiprolol, bisoprolol and irbesartan respectively. Intra- and inter-day relative standard deviations for all compounds were, in any case, lower than 11% and the method exhibits a convenient accuracy (percentage of relative error lower than 6% for each drug). In each case, the LOD were sufficient to detect post dose trough concentrations for checking patient's observance. Moreover, selectivity towards either endogenous species or co-administered drugs was demonstrated by combination of the use of the solid phase extraction process, gradient elution and diode array detection facilities, making thus, the proposed technique especially suitable for routine drug monitoring of resistant hypertensive patients.

Antihypertensive Agents↗

PubMed2000

Lycopene in tomatoes: chemical and physical properties affected by food processing.

Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalability, pharmacology, biochemistry, and physiology must be done to reveal the mechanism of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer demand for healthy food products provides an opportunity to develop lycopene-rich food as new functional foods, as well as food-grade and pharmaceutical-grade lycopene as new nutraceutical products. An industrial scale, environmentally friendly lycopene extraction and purification procedure with minimal loss of bioactivities is highly desirable for the foods, feed, cosmetic, and pharmaceutical industries. High-quality lycopene products that meet food safety regulations will offer potential benefits to the food industry.

Antioxidants↗

PubMed2000

Lycopene in tomatoes: chemical and physical properties affected by food processing.

Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalability, pharmacology, biochemistry, and physiology must be done to reveal the mechanism of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer demand for healthy food products provides an opportunity to develop lycopene-rich food as new functional foods, as well as food-grade and pharmaceutical-grade lycopene as new nutraceutical products. An industrial scale, environmentally friendly lycopene extraction and purification procedure with minimal loss of bioactivities is highly desirable for the foods, feed, cosmetic, and pharmaceutical industries. High-quality lycopene products that meet food safety regulations will offer potential benefits to the food industry.

Anticarcinogenic Agents↗

PubMed1996

New opportunities from the isolation and utilization of whey proteins.

Management of dairy whey has often involved implementation of the most economical disposal methods, including discharge into waterways and onto fields or simple processing into low value commodity powders. These methods have been, and continue to be, restricted by environmental regulations and the cyclical variations in price associated with commodity products. In any modern regimen for whey management, the focus must therefore be on maximizing the value of available whey solids through greater and more varied utilization of the whey components. The whey protein constituents offer tremendous opportunities. Although whey represents a rich source of proteins with diverse food properties for nutritional, biological, and functional applications, commercial exploitation of these proteins has not been widespread because of a restricted applications base, a lack of viable industrial technologies for protein fractionation, and inconsistency in product quality. These shortcomings are being addressed through the development of novel and commercially relevant whey processing technologies, the preparation of new whey protein fractions, and the exploitation of the properties of these fractions in food and in nontraditional applications. Examples include the following developments: 1) whey proteins as physiologically functional food ingredients, 2) alpha-lactalbumin and beta-lactoglobulin as nutritional and specialized physically functional food ingredients, and 3) minor protein components as specialized food ingredients and an important biotechnological reagents. Specific examples include the isolation and utilization of lactoferrin and the replacement of fetal bovine serum in tissue cell culture applications with a growth factor extract isolated from whey.

Animals↗

PubMed1994

[Immunologic reactions in poultry-processing workers].

The relationship between respiratory symptoms and immunological reactions was studied in 57 female workers holding jobs in the poultry food processing industry and in 51 non-exposed female workers. The prevalence of all chronic respiratory symptoms was significantly higher in exposed than in control workers (P < 0.01) except for occupational asthma. The prevalence of chronic respiratory symptoms in exposed workers was highest for chronic cough (49.1%), followed by dyspnoea (43.9%), rhinitis (38.6%), chronic phlegm (31.6%) and chronic bronchitis (26.3%). Occupational asthma was found in 5.3% of exposed workers. Exposed workers with positive skin prick test to poultry food demonstrated a higher prevalence of all chronic respiratory symptoms than those with negative skin tests, although the difference was statistically significant only for rhinitis (P < 0.05). The most frequent positive skin reactions were found for poultry food extract (exposed: 66.7%; control: 25.5%; P < 0.05). Increased IgE serum level was found in 19 (33.3%) exposed and in four (7.8%) control workers (P < 0.01). Three exposed workers with occupational asthma demonstrated increased IgE serum level. Our data indicate that occupational exposure to poultry food dust may be associated with the development of chronic respiratory symptoms and immunological changes in exposed workers.

Adult↗

PubMed1994

A field study of environmental impacts at a bleached kraft pulp mill site on the Baltic Sea coast.

The rate of technical development in bleaching of chemical pulp and the upgrading of process control and wastewater treatment systems in the pulp industry have been extremely rapid over the past few years. When assessing the environmental impacts of bleached kraft pulp mill effluents (BKMEs), it is therefore more important than ever to carefully characterize the bleaching process, the composition of the treated effluent, and the degree of exposure of sensitive target organisms in the receiving water body. These requirements have not always been fulfilled in previous reports on biological effects of BKMEs in Scandinavia. This work presents the results of a comprehensive field study of the impacts of a 350,000-tonne kraft mill, bleaching softwood and hardwood pulp in campaigns according to the sequence O(D25,C70+D5)(EOP)D(EP)D. The effluent is treated in an aerated lagoon with a mean retention time of 8-9 days, practically eliminating chlorate and resin acids, and reducing the discharge of adsorbable organic halogen (AOX) to an average of 1 t/day (1.3 and 0.4 kg/ADt for softwood and hardwood, respectively). The treated effluent is discharged through a 1.3-km-long diffuser, at a water depth of 9-12 m, into a well ventilated coastal area, giving a 1000-fold dilution within 3-4 km from the diffuser. The actual exposure of the coastal ecosystem to BKME components was determined by analysis of extractable organic chlorine in suspended solids and of conjugates of chlorophenolics in the bile of feral perch. Despite a major damage to the benthic communities that occurred about 10 years ago, and was due to large chlorate discharges at the time, no direct detrimental effects on benthic flora and fauna could be ascribed to the present BKME discharge. Instead, a clear recovery of the Fucus community, although not yet completed, could be demonstrated. Studies of the composition, abundance and biomass of the fish community, the recruitment and survival of fish fry, and the physiological status of perch, using a set of biomarkers, revealed that even in the most BKME-exposed area, only minor effects were detected. These effects were related to eutrophication/enrichment rather than to the action of toxic substances. The general effect picture, thus, was essentially of a different type than the one recorded in previous studies of mills, which used older technology and less effective process and effluent treatment control, and which were discharging into enclosed, shallow bays of the Baltic Sea.

Animals↗

PubMed2001

Yield production, chemical composition, and functional properties of emulsifier H28 synthesized by Halomonas eurihalina strain H-28 in media containing various hydrocarbons.

Halomonas eurihalina strain H-28 is a moderately halophilic bacterium that produces an extracellular polysaccharide not only in media with glucose but also in media supplemented with hydrocarbons (n-tetradecane, n-hexadecane, n-octane, xylene, mineral light oil, mineral heavy oil, petrol, or crude oil). In this study we investigated yield production, chemical composition, viscosity, and emulsifying activity of exopolysaccharides (EPS) extracted from the different media used. The largest amounts of biopolymer were synthesized in media with glucose and n-hexadecane. Chemical composition varied with culture conditions; thus EPS from cultures grown in the presence of hydrocarbons had lower contents of carbohydrates and proteins than EPS from media with glucose. However, the percentages of uronic acids, acetyls, and sulfates were always higher than glucose EPS. Crude oil was the substrate most effectively emulsified. All EPS were capable of emulsifying crude oil more efficiently than the three control surfactants tested (Tween 20, Tween 80, and Triton X-100). All polymers gave low viscosity solutions. EPS H28 could be attractive for application in the oil industry and/or in bioremediation processes, bearing in mind not only its functional properties, but also the capacity of producer strain H-28 to grow in the presence of high salt concentrations and oil substrates.

Culture Media↗

PubMed1999

High-performance liquid chromatographic-electrospray ionization mass spectrometric analyses for the integration of natural products with modern high-throughput screening.

Within the pharmaceutical industry, significant resources have been applied to the identification of new drug compound leads through the use of high-throughput screening (HTS). To meet the demand for rapid analytical characterization of biologically active samples identified by HTS, the technique of high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) has been utilized, and the application of this technique specifically for the integration of natural product sample mixtures into modern HTS is reviewed. The high resolution provided by reversed-phase HPLC coupled with the gentle and relatively universal ionization facilitated by the electrospray process has had significant impact upon a variety of procedures associated with the HTS of natural products, including extract sample diversity evaluation, dereplication, structure elucidation, preparative isolation, and affinity-based biological activity evaluation.

Chemistry, Pharmaceutical↗

PubMed2001

Characterization of soluble amaranth and soybean proteins based on fluorescence, hydrophobicity, electrophoresis, amino Acid analysis, circular dichroism, and differential scanning calorimetry measurements.

Intrinsic fluorescence (IF), surface hydrophobicity (S(o)), electrophoresis, amino acid analysis, circular dichroism (CD), and differential scanning calorimetry (DSC) were used to study folded and unfolded soluble proteins from Amaranthus hypochondriacus (A. h.) and soybean (S). Globulin (Glo) and albumin subfractions (Alb-1 and Alb-2) were extracted from A. h. and S and denatured with urea. Electrophoretic and functional properties indicated a significant correlation between soluble protein fractions from soybean and amaranth. The protein fractions shared some common electrophoretic bands as well as a similar amino acid composition. The larger percent of denaturation in protein fractions, which is associated with enthalpy and the number of ruptured hydrogen bonds, corresponds to disappearance of alpha-helix. The obtained results provided evidence of differences in their secondary and tertiary structures. The most stable was Glo followed by the Alb-2 fraction. Predicted functional changes in model protein systems such as pseudocereals and legumes in response to processing conditions may be encountered in pharmaceutical and food industries. These plants can be a substitute for some cereals.

Albumins↗

PubMed1997

Urinary excretion of phenols as an indicator of occupational exposure in the coke-plant industry.

OBJECTIVE: In the present study the relationship between the level of exposure to o-cresol and of 2,4- +2,5-, 3,4-, and 3,5-xylenols and the urinary excretion of their metabolites was examined. The mixed exposure to phenolic derivatives of exposed workers during their work shift was monitored by personal air sampling of the breathing-zone air and by measurements of phenol, o-cresol, and xylenol isomer concentrations in shift-end urine. METHODS: The study subjects were 76 men working at a coke plant who were 22-58 years old and 34 nonexposed subjects. Concentrations of phenolic compounds were determined in the breathing-zone air during the work shift, whereas concentrations of phenol, cresol, and xylenol isomers were measured in urine collected after the work shift. Concentrations of phenols in air and urine were determined by gas chromatography with flame-ionization detection. Urine samples were extracted after acid hydrolysis of glucuronides and sulfates by solid-phase extraction. The gas chromatography-mass spectrometry method was applied to identify metabolites in urine samples. RESULTS: The time-weighted average concentrations of phenol, cresol, and xylenol isomers detected in breathing-zone air showed that the exposure level of the workers was relatively low. The geometric mean values were as follows: 0.26 mg/m3 for phenol, 0.09 mg/m3 for o-cresol, 0.13 mg/m3 for p- and m-cresol, and 0.02-0.04 mg/m3 for xylenols at the tar-distillation process. Corresponding urinary concentrations were 10.39, 0.53, and 0.25-0.88 mg/g creatinine for phenol, o-cresol, and xylenol isomers, respectively. The correlation coefficients between the o-cresol and 2,4-, 2,5-, 3,4-, and 3,5-xylenol concentrations measured in urine and in the breathing-zone air were statistically significant, varying in the range of 0.54-0.74 for xylenol isomers and being 0.69 for o-cresol. CONCLUSION: We have found that the presence of o-cresol and xylenol isomers in urine can be used as a biomarker for phenol exposure. Analysis performed on workers at the tar-distillation process showed that they were exposed to relatively low concentrations of phenolic compounds.

Adult↗

PubMed2004

Tocopherol measurement in edible products of vegetable origin.

Since natural antioxidants present increasing interest for food industry due to their beneficial effect on health, new potential sources have been screened among edible aromatic plants and a microalgae, Spirulina platensis. The determination was performed after optimising a previously validated method, because important differences have been found among values described in literature for tocopherol content in products of vegetable origin. Values obtained ranged from 3.42 mg alpha-tocopherol/100 g of dill to 132.2 mg/100 g of fresh bay and from 0.14 mg gamma-tocopherol/100 g of spearmint to 3.45 mg/100 g of parsley. In all cases results were calculated from fresh leaves. Preliminary experiments were developed with bay (Laurus nobilis) plant to devise the supercritical fluid extraction of tocopherols, generating environmentally friendly processes to selectively extract fractions enriched with antioxidant compounds while removing fractions corresponding to essential oils, that is, those that correspond to the characteristic aroma of the plants. Another striking result has been the tocopherol content in the microalgae, 1.3 mg alpha-tocopherol/100 g of dried commercial spirulina, which do not justify the supposed source of antioxidant vitamins. Results suggest the need of more reliable determinations of tocopherols in vegetable sources to be included in databases.

Chromatography, Supercritical Fluid↗

PubMed1980

[Organisation, installations and operation of a carcass rendering plant exemplified by the Regau by-products plant (author's transl)].

In Upper Austria, carcasses, offals and all kinds of animal material are collected in hygienically safe manner and taken to the Regau by-products plant. This plant was built in the light of the latest advances to keep environmental pollution at a minimum and is divided in a clean and unclean area. The raw material, including uncut carcasses, is dumped into troughs and then transported by a screw conveyor to the crusher. By steam pressure the material is pushed into a receptacle called "the gun" and from there it is conveyed to the extractor, which functions as sterilizer (30 min 134 degrees C), extractor and drier. The wet extraction procedure using perchloroethylene produces hygienically unobjectionable animal meal and fat. The method of deodorization, which was described in full detail, has made it possible to create not only optimum working conditions in the plant itself but also acceptable living conditions in the residential areas at a distance of some 400 m. Extensive automation of all processes results in optimum hygienic working conditions and also permits a reduction of the staff, in contrast to the conditions prevailing in the former knackeries.

Abattoirs↗

PubMed1991

The genetic toxicology of organic compounds in natural waters and wastewaters.

This review was drawn from the literature describing genotoxic organic compounds in natural water (rivers, lakes, streams) and wastewater, as well as from recent discussions with industrial scientists and environmental regulators. Testing of wastewaters for genotoxicity may become a routine requirement for some industrial wastewater discharge permits, not unlike the more common requirement for routine aquatic toxicity tests. The stimuli for this are concerns that aquatic organisms inhabiting waters impacted by wastewater discharges suffer an increased risk of genetic damage or cancer, and that humans utilizing these waters for recreational and drinking water purposes may suffer similar genetic or carcinogenic risks. Some evidence suggests that neoplasia in aquatic organisms is related to habitat contamination, yet field evaluations fail to substantiate adequately a cause-and-effect relationship. Because aquatic organisms respond like mammals to the same genotoxic compounds, the increased burden of genotoxic compounds to the environment may impact certain endemic species. Wastewater discharges may be one source of genotoxic organic compounds in those impacted areas. With respect to potential human health impacts, evidence is supportive of increased cancer risk to individuals drinking water from surface sources; however, this risk may or may not relate to whether the drinking water source received input of wastewater discharges or known carcinogens. Throughout the published literature reviewed herein, the Salmonella/Ames gene mutation test was widely used to assess genotoxic activity, although studies using indigenous plants and aquatic organisms as in vivo monitors of genotoxic activity exist. No "standard" or frequently followed protocols for sample collection, sample processing, selection of tests or their conduct, or interpretation of data exist for most of the genotoxicity studies reviewed. For the Salmonella/Ames test, the aqueous samples were concentrated usually on XAD resin or by liquid:liquid extraction, and without this concentration step few samples exhibited genotoxic activity. Hence, in most instances, the ambient concentration of the compounds causing this activity is below that which is readily detectable by this test, a finding not new to this review. In contrast, aquatic organisms in laboratory and field studies responded to ambient concentrations of genotoxic compounds, thus alleviating the need for sample concentration. However, there appears to be a reluctance to utilize this information for extrapolation to potential human health effects. Unfortunately, no generally accepted and scientifically validated protocol for preparing aqueous samples for genotoxicity testing exists. Developing such a protocol is necessary before embarking on widespread genotoxicity testing of wastewaters, especially if results are to be used for permit compliance.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗