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Food Contamination (food + contamination)
Selected AbstractsInfluence of temperature on biofilm formation by Listeria monocytogenes on various food-contact surfaces: relationship with motility and cell surface hydrophobicityJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008G. Di Bonaventura Abstract Aims:, To assess the ability of Listeria monocytogenes to form biofilm on different food-contact surfaces with regard to different temperatures, cellular hydrophobicity and motility. Methods and Results:, Forty-four L. monocytogenes strains from food and food environment were tested for biofilm formation by crystal violet staining. Biofilm levels were significantly higher on glass at 4, 12 and 22°C, as compared with polystyrene and stainless steel. At 37°C, L. monocytogenes produced biofilm at significantly higher levels on glass and stainless steel, as compared with polystyrene. Hydrophobicity was significantly (P < 0·05) higher at 37°C than at 4, 12 and 22°C. Thirty (68·2%) of 44 strains tested showed swimming at 22°C and 4 (9·1%) of those were also motile at 12°C. No correlation was observed between swimming and biofilm production. Conclusions:,L. monocytogenes can adhere to and form biofilms on food-processing surfaces. Biofilm formation is significantly influenced by temperature, probably modifying cell surface hydrophobicity. Significance and Impacts of the Study:, Biofilm formation creates major problems in the food industry because it may represent an important source of food contamination. Our results are therefore important in finding ways to prevent contamination because they contribute to a better understanding on how L. monocytogenes can establish biofilms in food industry and therefore survive in the processing environment. [source] Cytotoxic Bacillus spp. belonging to the B. cereus and B. subtilis groups in Norwegian surface watersJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2004Ø. Østensvik Abstract Aims:, To investigate the presence and numbers of Bacillus spp. spores in surface waters and examine isolates belonging to the B. cereus and B. subtilis groups for cytotoxicity, and to discuss the presence of cytotoxic Bacillus spp. in surface water as hazard identification in a risk assessment approach in the food industry. Methods and Results:, Samples from eight different rivers with variable degree of faecal pollution, and two drinking water sources, were heat shocked and examined for the presence of Bacillus spp. spores using membrane filtration followed by cultivation on bovine blood agar plates. Bacillus spp. was present in all samples. The numbers varied from 15 to 1400 CFU 100 ml,1. Pure cultures of 86 Bacillus spp. isolates representing all sampling sites were characterized using colony morphology, atmospheric requirements, spore and sporangium morphology, and API 50 CHB and API 20E. Bacillus spp. representing the B. cereus and B. subtilis groups were isolated from all samples. Twenty-one isolates belonging to the B. cereus and B. subtilis groups, representing eight samples, were screened for cytotoxicity. Nine strains of B. cereus and five strains belonging to the B. subtilis group were cytotoxic. Conclusions:, The presence of cytotoxic Bacillus spp. in surface water represents a possible source for food contamination. Filtration and chlorination of surface water, the most common drinking water treatment in Norway, do not remove Bacillus spores efficiently. This was confirmed by isolation of spores from tap water samples. Significance and Impact of the Study:, Contamination of food with water containing low numbers of Bacillus spores implies a risk for bacterial growth in foods. Consequently, high numbers of Bacillus spp. may occur after growth in some products. High numbers of cytotoxic Bacillus spp. in foods may represent a risk for food poisoning. [source] The demand impacts of chicken contamination publicity,a case studyAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 4 2002Roger A. Dahlgran Adverse publicity regarding food contamination can depress demand, causing lost producer revenue. This study addresses the magnitude of those losses through the analysis of the impact of TV and print news coverage of bacterial contamination of chicken in the United States. An inverse demand model for chicken is estimated using weekly data from 1982 through 1991. Our findings indicate adverse publicity about salmonella contamination of chicken depressed the demand for chicken, but that the effect was small, less than 1% during the period of maximum exposure. Further, consumers soon forget this news as they reverted to prior consumption patterns in a matter of weeks. [EconLit citation: D120] © 2002 Wiley Periodicals, Inc. [source] Aflatoxin contamination of consumer milk caused by contaminated rice by-products in compound cattle feedJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2009Erik Nordkvist Abstract BACKGROUND: Elevated levels of aflatoxin M1 were observed in routine checks of consumer milk in southern Sweden in early 2006. A trace-back study revealed contaminated milk from several farms, and a total of 68 farms were banned from delivering milk to dairies for shorter or longer periods. The maximum level of aflatoxin M1 in a single sample from an individual farm was 257 ng kg,1 fresh milk. RESULTS: Aflatoxin analyses of commercial compound feed revealed that the contamination originated from the ingredient rice feed meal, a by-product from the preparation of Basmati rice for human consumption. Up to 56 µg kg,1 of aflatoxin B1 was found in rice feed meal at one feed mill. CONCLUSION: The present example shows that an aflatoxin-contaminated minor feed ingredient included at less than 10% (w/w) of compound cattle feed can significantly contaminate the milk produced. This emphasises the need for effective monitoring of the feed chain of food-producing animals in order to prevent food contamination. Copyright © 2008 Society of Chemical Industry [source] Using Empirical Likelihood to Combine Data: Application to Food Risk AssessmentBIOMETRICS, Issue 1 2009Amélie Crépet Summary This article introduces an original methodology based on empirical likelihood, which aims at combining different food contamination and consumption surveys to provide risk managers with a risk measure, taking into account all the available information. This risk index is defined as the probability that exposure to a contaminant exceeds a safe dose. It is naturally expressed as a nonlinear functional of the different consumption and contamination distributions, more precisely as a generalized U-statistic. This nonlinearity and the huge size of the data sets make direct computation of the problem unfeasible. Using linearization techniques and incomplete versions of the U-statistic, a tractable "approximated" empirical likelihood program is solved yielding asymptotic confidence intervals for the risk index. An alternative "Euclidean likelihood program" is also considered, replacing the Kullback,Leibler distance involved in the empirical likelihood by the Euclidean distance. Both methodologies are tested on simulated data and applied to assess the risk due to the presence of methyl mercury in fish and other seafood. [source] The ,Malbouffe' Saga La Saga de la ,Malbouffe' Die Saga von ,Malbouffe"EUROCHOICES, Issue 1 2007Alain Rérat summary The ,Malbouffe' Saga After the end of the Second World War, a marked increase in animal and plant production was observed in France, little by little considered by consumers to be obtained at the expense of product quality. The pejorative term ,malbouffe' soon emerged, in connection not only with the hygiene of food, but also with its organoleptic and technological characteristics. This article focuses on food safety in France, with special attention paid to the incidence of toxi-infections and food contaminations of biological and chemical origin. The Mad Cow outbreak is reviewed, along with its consequences for human health in the form of new variant Creutzfeldt-Jakob's disease. It is emphasized that food-related human mortality , almost exclusively due to biological contaminations , represented only 647 cases in 1995, i.e., 0.12 per cent of the overall mortality rate. The main contaminants were Salmonella, whose number is steadily decreasing, and Campylobacter, but parasite and phycotoxic risks are increasing. Mortality due to chemical contaminants is very low i.e., 10 cases or 0.002 per cent of overall mortality These contaminants, either accidental (dioxin, hydrocarbons, radioactive isotopes) or unavoidable (residues from phytochemicals, fertilisers) may be at the source of acute or chronic intoxications with sometimes unknown consequences. Nevertheless, food safety in France does not merit the spiteful term ,malbouffe'. Nach dem Ende des Zweiten Weltkriegs war in Frankreich im Bereich der Tier- und Pflanzenproduktion ein deutlicher Zuwachs zu beobachten, welcher in den Augen der Verbraucher zunehmend auf Kosten der Produktqualität erreicht wurde. Der abwertende Begriff ,Malbouffe" (in etwa ,schlechtes Essen") entstand bald darauf nicht nur im Hinblick auf die Nahrungsmittelhygiene, sondern auch in Bezug auf die organoleptischen und technologischen Eigenschaften der Nahrungsmittel. Dieser Beitrag konzentriert sich auf die Nahrungsmittelsicherheit in Frankreich unter besonderer Berücksichtigung der aufgetretenen Infektionen durch Giftstoffe und der Kontamination von Nahrungsmitteln biologischen und chemischen Ursprungs. Der BSE-Ausbruch und dessen Auswirkungen auf die Gesundheit des Menschen in Form von einer neuen Variante der Creutzfeldt-Jakob-Krankheit werden noch einmal betrachtet. Es wird hervor gehoben, dass die nahrungsmittelbedingte Sterblichkeit bei Menschen, die nahezu ausschließlich auf biologische Kontaminationen zurückzuführen ist, 1995 bei nur 647 Fällen lag, d.h. bei 0,12 Prozent der gesamten Sterblichkeitsrate. Die Nahrungsmittel wurden hauptsächlich durch Salmonellen (die Anzahl dieser Fälle nimmt kontinuierlich ab) und Campylobacter kontaminiert, die parasitären und phykotoxischen Risiken nehmen jedoch zu. Die auf chemische Kontaminationen zurückzuführende Sterblichkeit ist sehr gering und macht zehn Fälle oder 0,002 Prozent der gesamten Sterblichkeitsrate aus. Bei diesen Kontaminationen, die entweder zufällig herbei geführt werden (durch Dioxin, Kohlenwasserstoff, radioaktive Isotope) oder unvermeidbar sind (durch Rückstände pfl anzenchemischer Substanzen, Düngemittel), könnte es sich um die Ursache für akute oder chronische Vergiftungen handeln, welche zum Teil unbekannte Konsequenzen nach sich ziehen. Dennoch hat die Nahrungsmittelsicherheit in Frankreich den verächtlichen Begriff ,Malbouffe" nicht verdient. Après la fi n de la deuxième guerre mondiale, l'agriculture française a connu une augmentation spectaculaire des rendements des productions animale et végétale, rapidement accusée d'avoir été obtenue aux dépens de la qualité des produits consommés. Ainsi est apparue le terme barbare de «malbouffe», lié dans l'esprit des consommateurs, non seulement aux qualités hygiéniques de l'alimentation, mais également à ses caractéristiques sensorielles, voire technologiques. Ce rapport se focalise uniquement sur la salubrité alimentaire en France, soulignant, en particulier, l'évolution de l'incidence des toxi-infections et des contaminations alimentaires d'origine biologique et chimique. Après avoir rappelé l'épizootie de la vache folle (1000 cas en France depuis 1996 et actuellement en cours d'extinction) et de ses conséquences sur la santé humaine (nouvelle variante de la maladie de Creutzfeldt-Jakob) limitées actuellement à 13 cas mortels dans notre pays, ce rapport précise que la mortalité humaine liée à l'alimentation , presque totalement due à des contaminations biologiques - ne représentait en 1995 que 647 cas, i.e. 0.12% de la mortalité générale. Pour l'essentiel, ces contaminants sont des salmonelles, en baisse constante, et des campylobacter, mais on peut craindre la progression des risques parasitaires et phycotoxiques, encore réduits actuellement. La mortalité liée aux contaminants chimiques est très faible (10 cas, i.e. 0.002% de la mortalité générale); mais ces contaminants -qu'ils soient accidentels (dioxine, hydrocarbures, isotopes radio-actifs,) ou inévitables (résidus de phytosanitaires, d'engrais,)- peuvent être à l'origine de crises aiguës ou d'intoxications chroniques dont on ne connaît pas toujours les implications. Néanmoins, dans l'ensemble, la salubrité alimentaire en France ne mérite nullement la connotation malveillante du terme «malbouffe». [source] | ||||||||||