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At least 685 records · Page 38Linked to original sources
PubMed2006

Contamination of dry foods with trimethyldiphenylmethanes by migration from recycled paper and board packaging.

Contamination of foods with trimethyldiphenylmethanes is reported and the origin is shown to be migration from food packaging materials of which the use of recycled carbonless copy paper was found to be the major source. This chemical is one of the solvents used in the carbonless copy paper and its presence in food and the environment has not been previously identified. In this paper we have pursued previous studies on diisopropylnaphthalenes and hydrogenated terphenyls contamination from packaging and now report the identification of this new food contaminant and present evidence of its source. Solid foods such as egg pasta, barley coffee and rice were analysed by GC/MS and a mean concentration of 18 microg/kg of trimethyldiphenylmethanes was found. Extracts from carbonless copy paper were analysed by proton NMR to characterize the trimethyldiphenylmethanes. Since trimethyldiphenylmethanes are found in solid food together with diisopropylnaphthalenes, and considering their similar chemical character, they may follow the same migration pathway as one another.

Chromatography, High Pressure Liquid↗
PubMed1974

Enumeration of food-borne Clostridium perfringens in egg yolk-free tryptose-sulfite-cycloserine agar.

The SFP (Shahidi-Ferguson perfringens), TSC (tryptose-sulfite-cycloserine), EY (egg yolk)-free TSC, and OPSP (oleandomycin-polymyxin-sulfadiazine perfringens) agars have been tested for their suitability to enumerate Clostridium perfringens in naturally contaminated foods. Complete recoveries of C. perfringens were obtained in each of the four media, but only the TSC and EY-free TSC agars were sufficiently selective to ensure subsequent confirmatory tests without interference from facultative anaerobes. Because of some disadvantages associated with the use of egg yolk, EY-free TSC agar is recommended for enumeration of C. perfringens in foods. Several conditions for convenient shipment of foods and C. perfringens isolates with minimum loss of viability have been tested. The highest viable counts were preserved when foods were mixed 1:1 (wt/vol) with 20% glycerol and kept in a container with dry ice. Isolated C. perfringens strains remained viable for at least 2 weeks at ambient temperatures on blood agar slopes with a 2% agar overlay in screw-cap culture tubes.

Agar↗
PubMed2001

Reproductive and transgenerational effects of methylmercury or Aroclor 1268 on Fundulus heteroclitus.

This research determined the potential for methylmercury or Aroclor 1268 to disrupt reproduction and sexual differentiation in Fundulus heteroclitus. The research determined whether fish that are exposed to mercury or Aroclor 1268 survive and successfully reproduce; whether offspring of exposed fish hatch, survive, produce eggs, and fertilize them; and whether the second-generation offspring of exposed fish hatch and survive. Fundulus heteroclitus were exposed to mercury or Aroclor 1268 via contaminated food. Endpoints evaluated included survival, growth, fecundity, fertilization success, hatch success, larval survival, sex ratios, and the prevalence of gonadal abnormalities. In general, polychlorinated biphenyls were highly bioavailable and accumulated well through feeding. The only statistically significant effect observed as a result of treatment with Aroclor 1268 was an increase in growth in the offspring of exposed fish. Mercury was accumulated in a dose-dependent fashion via food exposures. Exposure to mercury in food increased mortality in male F. heteroclitus, which possibly occurred as a result of behavioral alterations. Increased mortality was observed at body burdens of 0.2 to 0.47 microgram/g. Offspring of F. heteroclitus fed mercury-contaminated food were less able to successfully reproduce, with reduced fertilization success observed at egg concentrations of 0.01 to 0.63 microgram/g, which corresponds with parent whole-body concentrations of 1.1 to 1.2 micrograms/g. Offspring of exposed fish also had altered sex ratios, with treatment at moderate concentrations producing fewer females and treatment at the highest concentration producing more females than expected. Alterations in sex ratios were observed at concentrations of less than 0.01 microgram/g in eggs or between 0.44 and 1.1 micrograms/g in parents. Offspring of mercury-exposed fish also had increased growth in moderate treatments, when egg concentrations were less than 0.02 microgram/g, or when parent whole bodies contained 0.2 to 0.47 microgram/g. In summary, exposure to mercury reduced male survival, reduced the ability of offspring to successfully reproduce, and altered sex ratios in offspring. Both direct effects on exposed fish and transgenerational effects were observed.

Animals↗
PubMed1971

Enumeration and identification of Bacillus cereus in foods. I. 24-hour presumptive test medium.

An egg yolk-polymyxin medium (KG) for rapid enumeration of Bacillus cereus is described. The test is presumptive in that differentiation of B. cereus (and closely related organisms) from other species is based on the formation of turbidity in the agar surrounding the colonies of the cereus group organisms. The medium is formulated to encourage sporulation and release of free spores for serological confirmatory tests within the 24-hr incubation period. The production of turbidity in egg yolk and free-spore production by 25 strains of B. cereus on KG agar were measured. The recovery of food poisoning strains of B. cereus inoculated into nonsterile food slurries was assessed. A comparison of KG agar and mannitol-egg yolk-polymyxin-agar indicated that the two media were comparable in their abilities to recover low levels of B. cereus from naturally contaminated foods. Since KG agar enhances spore formation by B. cereus, thus permitting early serological testing, its use in screening food products is advocated.

Bacillus cereus↗
PubMed2005

Dietary exposure to chemical migrants from food contact materials: a probabilistic approach.

A two-dimensional probabilistic model has been developed to estimate the short-term dietary exposure of UK consumers to migrants from food packaging materials. The current EU approach uses a default scenario of assuming that all individuals are 60 kg weight and consume 1 kg of food packaged in the material of interest per day. Using four UK National Dietary and Nutrition Surveys comprising 4-7 day dietary records for different age groups and survey years, a sample representative of the UK population has been obtained consuming around 4200 different food items. Each survey provides records for around 2000 individuals and supplies detailed information on the consumption of food and data on sex, height and socio-economic status which may be used to analyse the exposure of selected groups within the community. As a result we are able to address the variation in consumption of food amongst individuals, and account for actual body weights providing a more accurate representation of the 'true' exposure. The migrants bisphenol A diglycidyl ether (BADGE), di-2-ethylhexyl adipate (DEHA) and styrene were considered as specimen compounds although the methodology employed has the flexibility to adapt to other migrants and packaging types and indeed other food contaminants. Exposure for each individual is estimated by calculating and summing the individual exposure from each item in their diet, and is repeated for all individuals in each survey to produce a distribution of exposures for the population. The packaging type of each food item is assigned by utilizing known packaging types from the database or, by sampling from a distribution based upon market share information. The parameters contributing towards the exposure from a packaged dietary item are migrant concentration and item weight. Distributions are used to represent the inherent variation and uncertainty affecting these parameters. Where data on concentrations for a particular type of food are lacking, expert judgement is used to extrapolate from available data for other food types. The model can also be run using only migration data for food simulants. In this case, concentrations expected for each of the food items are assigned based on the data for the relevant food simulant. The primary outputs of the model are distributions of estimated daily intakes for the selected population. Each distribution gives the variation across the population subject to the uncertain parameters sampled in that iteration of the model. Analysing the ensemble of distributions allows us to obtain the confidence limits around estimates for percentiles due to the uncertainties. The probabilistic approach allows sensitivity analysis to evaluate the relative importance of the input parameters and places confidence bounds on the outputs to show the effect of the uncertainties and the contribution of each food type toward the overall exposure.

Adipates↗
PubMed1996

The effect of Zn on the digestive gland epithelium of Porcellio scaber (Isopoda, Crustacea).

The effect of zinc (Zn)-contaminated food on the shape of digestive gland epithelium was studied in the terrestrial isopod, Porcellio scaber. In animals fed with 5,000 micrograms Zn g-1 dry wt. of food, the epithelium was flattened in the anterior part of the gland tube. In the posterior part of the gland tube, the shape and size of cells did not change drastically, but they had folded apical surface. In animals fed with more Zn-contaminated food (10,000 micrograms Zn g-1 dry wt.) the epithelium was uniformly flattened and the basal lamina was intensively folded. In both cases, reduction of lipid bodies was evident. The possibility of using the shape of the gland epithelium as a biomarker of toxic chemicals is discussed.

Animals↗
PubMedDate not supplied

[Organic pathomorphological changes in animals with dietary infection by food products contaminated by Bacillus cereus].

The authors noticed marked vascular disorders in the capillary system, focal hemorrhages, and inflammatory, largely proliferative reactions in the stroma coupled with dystrophic and necrotic changes in parenchymal elements. The changes were found to be the most pronounced in the intestine, liver, myocardium, and in brain tissue. The degree of the lesions depended on the microorganism dosage. Provided the food contained 10(9)/g Bac. cereus, the injuring action was recorded to be more powerful, which manifested in the increased extent of vascular disorders with the hemorrhagic manifestations, thrombus formation in the vessels of the brain, heart, lungs, stomach and intestine, augmentation of dystrophic changes in organ parenchymal elements.

Animals↗
PubMed1979

Role of the fly in the transport of Yersinia enterocolitica.

Yersinia enterocolitica were isolated from flies collected from a piggery and a kitchen of farm and from ham hung in a piggery. The cultures were identified as Y. enterocolitica biovar 4 and serovar 3 by biochemical and serological characteristics. From these results it is suggested that flies may play an important role in food contamination by Y. enterocolitica. In this study, the probable donors of Y. enterocolitica to the flies were swine.

Animals↗
PubMed2003

Rapid electrochemical detection and identification of catalase positive micro-organisms.

The rapid detection and identification of bacteria has application in a number of fields, e.g. the food industry, environmental monitoring and biomedicine. While in biomedicine the number of organisms present during infection is multiples of millions in the other fields it is the detection of low numbers of organisms that is important, e.g. an infective dose of Escherichia coli O157:H7 from contaminated food is less than 100 organisms. A rapid and sensitive technique has been developed to detect low numbers of the model organism E. coli O55, combining Lateral Flow Immunoassay (LFI) for capture and amperometry for sensitive detection. Nitrocellulose membranes were used as the solid phase for selective capture of the bacteria using antibodies to E. coli O55. Different concentrations of E. coli O55 in Ringers solution were applied to LFI strips and allowed to flow through the membrane to an absorbent pad. The capture region of the LFI strip was placed in close contact with the electrodes of a Clarke cell poised at +0.7 V for the detection of hydrogen peroxide. Earlier research identified that the consumption of hydrogen peroxide by bacterial catalase provided a sensitive indicator of aerobic and facultative anaerobic microorganisms numbers. Modification and application of this technique to the LFI strips demonstrated that the consumption of 8 mM hydrogen peroxide was correlated with the number of microorganisms presented to the LFI strips in the range of 2 x 10(1)-2 x 10(7) colony forming units (cfu). Capture efficiency was dependent on the number of organisms applied and varied from 71% at 2 x 10(2) cfu to 25% at 2 x 10(7) cfu. The procedure was completed in less than 10 min and could detect less than 10 cfu captured from a 200 microl sample applied to the LFI strip. The approached adopted provides proof of principle for the basis of a new technological approach to the rapid, quantitative and sensitive detection of bacteria that express catalase activity.

Biosensing Techniques↗
PubMed2003

Symmetric focal degeneration in the cerebellar and vestibular nuclei in swine caused by ingestion of Aeschynomene indica seeds.

A vestibulocerebellar disorder was observed in 2- to 4-month-old swine after consumption of broken rice contaminated with 13% Aeschynomene indica seeds. Affected animals recovered in 2-14 days after removal of the contaminated food. To reproduce the syndrome, 10 pigs were fed 13% A. indica seeds in commercial pig ration or rice. They showed clinical signs similar to those observed in the spontaneous cases, 1 hour to 6 days after ingestion. Three pigs recovered after the withdrawal of the contaminated food. The others were killed. Two pigs that were fed for 25 days with food containing 3% and 6% seeds and two control pigs did not show clinical signs. Histologic lesions were characterized by symmetric focal degeneration in the cerebellar and vestibular nuclei. The initial lesion, observed 24 hours after the first ingestion, was characterized by vacuolation of the neuropil. Subsequently, there was progressive loss of parenchyma, vascular reaction, a few small spheroids, astrocytosis, and accumulation of gitter cells. The brains from four pigs were perfused with a buffered solution of glutaraldehyde-paraformaldehyde 12-48 hours after they started to ingest the seeds. No ultrastructural lesions were observed in the cerebellar nuclei after 12 hours of seed consumption. At 24 hours, endothelial cells and pericytes were separated by empty spaces from astrocyte foot processes, suggesting perivascular edema. The astrocytes were enlarged, consistent with intracellular fluid accumulation. These results suggest that A. indica seeds are toxic, causing functional derangement of the vestibulocerebellar system, followed by alterations in the microvasculature in the cerebellar and vestibular nuclei.

Animals↗
PubMed2003

Finding optimal photosensitisers for the decontamination of foods by the photodynamic effect.

A new method for sanitation based on the photodynamic effect is introduced. Photosensitisers are compounds that generate cytotoxic oxygen species and free radicals after excitation with appropriate visible light. The cell killing efficacy is due to their chemical structure, to the actual environment and therefore also to their degree of aggregation. As has been shown, photosensitisers bound to the cell wall or incorporated into the cells are very effective cytotoxic agents after illumination. Even singlet oxygen generated in the gas phase surrounding the micro-organisms effectively kills cells. Especially membrane components are the targets of the photodynamic effect. Membrane disintegration is observed soon after illumination. The food contaminants under investigation are Bacillus subtilis, Bacillus cereus, forming endospores, Staphylococcus aureus, forming a wide range of agressins, exotoxins and enterotoxins, all gram positive micro-organisms, Escherichia coli, a hygiene indicator, and the yeasts Saccharomyces cerevisiae, Kloeckera javanica, Rhodotorula mucilaginosa, a blue and a pink pigmented isolate from foods. We investigated the capacity of several photosensitisers to induce the phototoxic effect towards those micro-organisms following excitation by visible light.

Bacillus cereus↗
PubMed2003

Rapid detection of respiring Escherichia coli O157:H7 in apple juice, milk, and ground beef by flow cytometry.

BACKGROUND: Rapid and simple methods to detect viable pathogenic microbes in foods and drinks are required. Flow cytometry was used for the rapid detection of respiring Escherichia coli O157:H7 cells in apple juice, milk, and ground beef. METHODS: CTC (5-cyano-2,3-ditolyl tetrazolium chloride) was used to estimate the respiratory activity of bacteria. Fluorescein isothiocyanate (FITC)-labeled anti-E. coli O157:H7 direct antibody (FA) was used for the specific detection of target cells. Food samples were inoculated with starved E. coli O157:H7 and E. coli K-12 cells, and analyzed by both fluorescent microscopy and flow cytometry after double staining with FA and CTC. RESULTS: Respiring E. coli O157:H7 cells in food samples showed strong fluorescence of both FA (green) and CTC (red); thus, they could be clearly and specifically distinguished from respiring E. coli K-12 or inactive cells. A good correlation was achieved in flow cytometric analysis between the numbers of inoculated viable E. coli O157:H7 and those detected in milk and apple juice. The detection threshold for this flow cytometry for E. coli O157:H7 in milk, apple juice, and ground beef was 10(3) cells/ml (milk and apple juice) or 10(3) cells/g (ground beef) of sample when the total bacterial number in the sample was 10(6) cells/ml. CONCLUSIONS: Respiring E. coli O157:H7 in food samples can be detected specifically within a few hours. Flow cytometry with FA-CTC double staining can be used to examine food contamination with various pathogenic microbes demonstrating physiologic activity through the use of a suitable fluorescent antibody.

Animals↗
PubMed1982

Epidemiological aspects of Campylobacter jejuni enteritis.

An epidemiological study on Campylobacter jejuni enterocolitis was performed in an urban Swedish community. The study included 55 patients gathered during a six-month period. Forty-one of the 55 patients (75%) were infected outside Sweden. Campylobacter enterocolitis was rare among children within the country. Patients infected in Sweden had eaten chicken significantly more often than a corresponding control group. Seven out of nine chicken consuming campylobacter patients also had prepared the fresh chicken alone, and none of their family members became ill. Thus the preparation of food contaminated with Campylobacter seems to elevate the risk for contracting the disease. Sick household pets transmitted the campylobacter infection to two patients. Forty-six of the patients had a total of 85 close household members. Three definite secondary cases were found. There was no evidence of transmission of Campylobacter by food prepared by two cooks who were working while still being asymptomatic excreters. Clinical reinfection with Campylobacter was observed in one patient. No patients became long-term carriers of Campylobacter.

Adolescent↗
PubMed2006

Cell death mechanisms in AtT20 pituitary cells exposed to polychlorinated biphenyls (PCB 126 and PCB 153) and methylmercury.

Polychlorinated biphenyls (PCBs) are persistent food contaminants that can have adverse effects on the endocrine and nervous systems, including the pituitary. In the present study, we have investigated cell death in the AtT20 pituitary cell line after exposure to coplanar PCB 126 and non-coplanar PCB 153. In addition, co-exposure to the PCBs and another neurotoxic food contaminant, methylmercury (MeHg), was studied to test possible interactive effects. Our results show that mainly necrosis is induced after exposure to the selected toxicants. Simultaneous exposure to moderately toxic doses of PCBs and MeHg resulted in additive or slightly synergistic effects on the induction of cell death. Furthermore, our data suggest that both PCB congeners trigger cell death in AtT20 cells via activation of calcium regulated calpains and lysosomal cathepsins, possibly through disruption of mitochondrial function and intracellular calcium signaling. However, caspase-activity appears not to be critical for PCB induced cell death in these cells. Presence of reactive oxygen species (ROS) and protective effects of pre-treatment with antioxidants were only found after MeHg exposure, suggesting that oxidative stress plays a major role in MeHg but not PCB toxicity in this experimental model.

Animals↗
PubMed2001

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market.

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GC-MS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1 mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl anti BFDGE.HCl.H2O at a level of 1.5 mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.

Benzhydryl Compounds↗