CTCPA

Nantes, France
Nantes, France

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Rigaux C.,French National Institute for Agricultural Research | Andre S.,CTCPA | Albert I.,French National Institute for Agricultural Research | Carlin F.,French National Institute for Agricultural Research | Carlin F.,University of Avignon
International Journal of Food Microbiology | Year: 2014

Microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as Geobacillus stearothermophilus, is a persistent problem in the food industry. An incubation test at 55°C for 7days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. We propose a microbial risk assessment model predicting the percentage of non-stability due to G. stearothermophilus in canned green beans manufactured by a French company. The model accounts for initial microbial contaminations of fresh unprocessed green beans with G. stearothermophilus, cross-contaminations in the processing chain, inactivation processes and probability of survival and growth. The sterilization process is modeled by an equivalent heating time depending on sterilization value F0 and on G. stearothermophilus resistance parameter zT. Following the recommendations of international organizations, second order Monte-Carlo simulations are used, separately propagating uncertainty and variability on parameters.As a result of the model, the mean predicted non-stability rate is of 0.5%, with a 95% uncertainty interval of [0.1%; 1.2%], which is highly similar to data communicated by the French industry. A sensitivity analysis based on Sobol indices and some scenario tests underline the importance of cross-contamination at the blanching step, in addition to inactivation due to the sterilization process. © 2013 Elsevier B.V.


Grob K.,Official Food Control Authority of the Canton of Zurich | Camus P.,4 ter rue du Bacco | Gontard N.,Montpellier University | Hoellinger H.,University of Paris Descartes | And 7 more authors.
Food Control | Year: 2010

Historically, due to the often overwhelming complexity of the substances migrating from food contact materials (FCMs) into food, the specific legislation in Europe started from the substances used to manufacture these materials and articles. There are, however, FCMs with migrates almost exclusively consisting of reaction products, such as those produced from resins used, e.g. for coatings (epoxy resins, polyesters, organosols, trimellitic acid resins). Since the reaction products do not necessarily have the same toxicological profile as the starting substances to produce the resins, the use of authorized starting substances does not rule out the migration of compounds endangering human health. The European framework Regulation 1935/2004 requires the safety of all substances migrating from FCMs into food. Resolution AP2004/1 on coatings of the Council of Europe puts the emphasis on the safety evaluation of the migrants rather than that of the substances used for manufacturing the resins and then the coatings. Nonetheless, the Code of Practice for Coatings recently issued by industry focuses on the evaluation of the starting substances to produce resins. The authors of this paper consider the present situation unsatisfactory. It is the duty of industry to respect the legal requirements and of the regulatory authorities to ensure that these requirements are met. The authors recommend setting a time limit to have this achieved. © 2009 Elsevier Ltd. All rights reserved.


Diao M.M.,French National Institute for Agricultural Research | Diao M.M.,University of Nantes | Andre S.,CTCPA | Membre J.-M.,French National Institute for Agricultural Research | Membre J.-M.,University of Nantes
International Journal of Food Microbiology | Year: 2014

Foodborne botulism is a serious disease resulting from ingestion of preformed Clostridium botulinum neurotoxin in foodstuff. Since the 19th century, the heat resistance of this spore forming bacteria has been extensively studied in order to guarantee the public health associated with low acidic, ambient stable products. The most largely used heat resistance parameters in thermal settings of such products are the D121.1°C values (time required to have a 10-fold decrease of the spore count, at 121.1°C) and the z-values (temperature increase to have a 10-fold decrease of D-values).To determine D121.1°C and z-values of proteolytic C. botulinum and its nontoxigenic surrogate strain C. sporogenes PA3679, a dataset of 911 D-values was collected from 38 scientific studies. Within a meta-analysis framework, a mixed-effect linear model was developed with the log D-value (min) as response and the heat treatment temperature as explicative variable. The studies (38), the C. botulinum strains (11), and the heat treatment media (liquid media and various food matrices, split into nine categories in total) were considered as co-variables having a random effect. The species (C. botulinum and C. sporogenes) and the pH (five categories) were considered as co-variables having a fixed effect.Overall, the model gave satisfactory results with a residual standard deviation of 0.22. The heat resistance of proteolytic C. botulinum was found significantly lower than the C. sporogenes PA 3679 one: the mean D-values at the reference temperature of 121.1. °C, in liquid media and pH neutral, were estimated to 0.19 and 1.28. min for C. botulinum and C. sporogenes, respectively. On the other hand, the mean z-values of the two species were similar: 11.3 and 11.1. °C for C. botulinum and C. sporogenes, respectively. These results will be applied to thermal settings of low-acid ambient stable products. © 2013.


Le Bourvellec C.,French National Institute for Agricultural Research | Le Bourvellec C.,University of Avignon | Bouzerzour K.,French National Institute for Agricultural Research | Bouzerzour K.,University of Avignon | And 7 more authors.
Journal of Food Composition and Analysis | Year: 2011

Apple fruit is well known for its health properties, ascribed to its content in both phenolics and fibres. As more and more apples are consumed after processing, there is a need to understand the impact of the conventional process on the nutritional potential of applesauce. We have investigated the variation in composition between fresh and processed apples of 12 cultivars, focussing on polysaccharides and polyphenols. The polysaccharide content estimated in the alcohol insoluble solid (AIS) of the apple flesh varied from 17 (cv. Greensleeves, obtention TMR 7 A 82) to 25 (cv. Jolyne) mg/g fresh weight. The AIS contents varied from 15 to 32. mg/g fresh weight in applesauce. The applesauces were fractionated into serum, containing low concentrations (<5. mg/g) of soluble fibres, and particles concentrating the fibres (40-60. mg/g) and the cellulose (>30% of the AIS). Total phenolic concentrations varied in the flesh from 578 (cv. Golden Delicious) to 1596. mg/kg fresh weight (cv. 3535), and in the peel from 1658 (cv. Greensleeves) to 7658. mg/kg fresh weight (cv. Sinta). The applesauces contained flavonols, coming from the skin, and slightly higher concentration of dihydrochalcones coming from the pips than the flesh. A dihydrochalcone oxidation product was also detected. The concentration of hydroxycinnamic acids and flavan-3-ols was decreased in proportions depending on the cultivar. The flavan-3-ols were concentrated in the particles of the applesauce. The composition of applesauce thus appeared to be very close to that of apple flesh. © 2011 Elsevier Inc.


PubMed | CTCPA, University of Avignon and French National Institute for Agricultural Research
Type: | Journal: International journal of food microbiology | Year: 2013

Microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as Geobacillus stearothermophilus, is a persistent problem in the food industry. An incubation test at 55 C for 7 days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. We propose a microbial risk assessment model predicting the percentage of non-stability due to G. stearothermophilus in canned green beans manufactured by a French company. The model accounts for initial microbial contaminations of fresh unprocessed green beans with G. stearothermophilus, cross-contaminations in the processing chain, inactivation processes and probability of survival and growth. The sterilization process is modeled by an equivalent heating time depending on sterilization value F and on G. stearothermophilus resistance parameter z(T). Following the recommendations of international organizations, second order Monte-Carlo simulations are used, separately propagating uncertainty and variability on parameters. As a result of the model, the mean predicted non-stability rate is of 0.5%, with a 95% uncertainty interval of [0.1%; 1.2%], which is highly similar to data communicated by the French industry. A sensitivity analysis based on Sobol indices and some scenario tests underline the importance of cross-contamination at the blanching step, in addition to inactivation due to the sterilization process.


PubMed | University of Nantes, CTCPA and French National Institute for Agricultural Research
Type: | Journal: International journal of food microbiology | Year: 2015

In this study, a risk assessment of proteolytic Clostridium botulinum in canned foie gras was performed, the number of illnesses per year in France due to C. botulinum in foie gras was estimated. Data on initial level in raw materials were collected at manufacturers and analysed using a Negative Binomial distribution. The effect of the usual foie gras heat treatment (equivalent time at 121 C: F0=0.5 min) was considered at two levels: first, it led to an inactivation (estimated to 2.3 log); second it led to a spore injury and then to a spore inhibition. This latter effect was assessed by analysing data from a challenge test study carried out with Clostridium sporogenes spores in the foie gras product. The probability of spore recovering after thermal inhibition was estimated to 9.510(-8) (corresponding to 7.0 log). The data on the consumption pattern were collected on the French market. The Quantitative Microbiological Risk Assessment (QMRA) model and all the assumptions are reported in detail in the study. The initial contamination of raw materials, effect of thermal treatment on microbial inactivation and spore inhibition were handled mathematically using a probabilistic framework, considering only the variability dimension. The model was implemented in Excel and run through Monte Carlo simulation, using @Risk software. In parallel, epidemiological data collected from the French Institute for Public Health Surveillance during the period 2001-2012 were used to estimate an Appropriate Level Of Protection (ALOP) and then a Food Safety Objective (FSO): ALOP equalled to 2.510(-3) illnesses per million inhabitant per year, FSO equalled to 1.410(-9) foie gras portions containing C. botulinum spore (expressed in decimal logarithm, FSO=-8.9). The QMRA model output values were smaller, but on the same order of magnitude as these two figures: 8.010(-4) illnesses per million inhabitants per year, and, 4.510(-10) (-9.3 log) foie gras portions containing C. botulinum spores able to recover. It was then possible to conclude that the current practices regarding thermal treatment of canned foie gras are sufficient to control the risk of C. botulinum in foie gras in France.


PubMed | CTCPA and University of Avignon
Type: | Journal: International journal of food microbiology | Year: 2015

Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery.


PubMed | CNRS Food Processing and Microbiology Laboratory, CTCPA and French National Institute for Agricultural Research
Type: | Journal: International journal of food microbiology | Year: 2014

The objective of this study was to develop a probabilistic model in order to determine the contamination level of Salmonella and Listeria monocytogenes in ready-to-cook poultry meat, after a high pressure (HP) treatment. The model included four steps: i) Reception of raw meat materials, mincing and mixing meat, ii) Partitioning and packaging into 200-g modified atmosphere packs, iii) High pressure treatment of the meat, and iv) Storage in chilled conditions until the end of the shelf-life. The model excluded the cooking step and consumption at consumers home as cooking practices and heating times are highly variable. The initial contamination level of Salmonella and L. monocytogenes was determined using data collected in meat primary processing plants. The effect of HP treatment and potassium lactate on microbial reduction was assessed in minced meat, using a full factorial design with three high pressure treatments (200, 350 and 500 MPa), three holding times (2, 8 and 14 min) and two potassium lactate concentrations (0 or 1.8% w/w). The inactivation curves fitted with a Weibull model highlighted that the inactivation rate was significantly dependent on the HP treatment. From the literature, it was established that Salmonella was not able to grow in the presence of lactate, under modified atmosphere and chilled conditions whereas the growth of L. monocytogenes was determined using an existing model validated in poultry (available in Seafood Spoilage and Safety Predictor software, V. 3.1). Once implemented in the Excel add-in @Risk, the model was run using Monte Carlo simulation. The probability distribution of contamination levels was determined for various scenarios. For an average scenario such as an HP treatment of 350 MPa for 8 min, of 200 g minced meat containing 1.8% lactate (pH 6.1; aw 0.96), conditioned under 50% CO2, the prevalence rate of Salmonella and L. monocytogenes, after a 20-day storage at 6 C was estimated to be 4.1% and 7.1%, respectively. The contamination level was low considering that the product is going to be cooked by the consumer afterwards: the 99th percentile of the distribution was equal to -2.3log cfu/g for Salmonella and 0.5log cfu/g for L. monocytogenes. More generally, the model developed here from raw material reception up to the end of the shelf-life enables to recommend combinations of HP treatment and lactate formulation to guarantee an acceptable microbial concentration before cooking.


PubMed | CTCPA and University of Avignon
Type: Journal Article | Journal: Food microbiology | Year: 2014

Geobacillus stearothermophilus is the main thermophilic spore former involved in flat sour spoilage of canned foods. Three typing methods were tested and applied to differentiate strains at intra-species level: panC sequence analysis, REP-PCR and M13-PCR. panC gene was highly conserved within the studied strains, suggesting a low intra-specific diversity. This was supported by REP-PCR primary assays and M13-PCR results. M13-PCR profile analysis succeeded in differentiating six closely related groups (at 79% threshold similarity) among 127 strains from a range of spoiled canned food products and from different canneries. Phenotypic traits were investigated among 20 selected strains representing groups and origins. Ranges of growth under different temperatures (from 40 C to 70 C), pH (from 5.0 to 6.5), NaCl concentrations (from 1 to 5%) and sporulation conditions poorly differed between strains, but wet heat resistance of spores showed a 20-fold variation between strains. Furthermore, in this study, strains that belonged to the same M13-PCR genetic group did not share phenotypic characteristics or common origin. The work emphasizes a low diversity within the G. stearothermophilus species but data from this study may contribute to a better control of G. stearothermophilus spoilage in canned food.


Duranton F.,French National Center for Scientific Research | Maree E.,French National Center for Scientific Research | Simonin H.,French National Center for Scientific Research | Cheret R.,CTCPA | De Lamballerie M.,French National Center for Scientific Research
High Pressure Research | Year: 2011

High pressure/high temperature (HPHT) processing is an innovative way to sterilize food and has been proposed as an alternative to conventional retorting. By using elevated temperatures and adiabatic compression, it allows the inactivation of vegetative microorganisms and pathogen spores. Even though the microbial inactivation has been widely studied, the effect of such process on sensorial attributes of food products, especially meat products, remains rare. The aim of this study was to investigate the potential of using HPHT process (500MPa/115°C) instead of conventional retorting to stabilize Toulouse sausages while retaining high organoleptic quality. The measurements of texture, color, water-holding capacity and microbial stability were investigated. It was possible to manufacture stable products at 500MPa/115°C/30min. However, in these conditions, no improvement of the quality was found compared with conventional retorting. © 2011 Taylor & Francis.

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