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Saint-Laurent-sur-Saône, France

Araujo M.M.,Brazilian Nuclear Energy Research Institute (IPEN) | Araujo M.M.,University of Strasbourg | Araujo M.M.,French National Center for Scientific Research | Marchioni E.,University of Strasbourg | And 9 more authors.
LWT - Food Science and Technology | Year: 2015

Folates compounds are a B group vitamin vital for important biochemical processes like DNA synthesis and repair and in certain biological reactions as a cofactor. Folic acid (FA) is composed of a pteridine ring, p-aminobenzoic acid and glutamate moieties. Separately, the three moieties have no vitamin activity. Folate deficiency can lead to increased risk of several pathologies. FA is known to be a sensitive compound, easily degraded by pH, light, heat and food processing. Food irradiation is a process exposing food to ionizing radiations to reduce storage losses, extend shelf life and microbiological safety. Radiation treatment produces oxygen radicals and thereby induces oxidative damage in biomolecules such as proteins, lipids, DNA and vitamins. In the present work, aqueous FA solutions are submitted to electron-beam (E-beam) radiation in a dose range of 0.25-10kGy. Upon irradiation, main FA radio-products are quantified by HPLC. E-beam processing undergoes radiolysis to yield some known FA photoproducts and also new radio-products are formed: 6-(hydroxymethyl)pterin and N-(4-nitrobenzoyl)- l-glutamic acid. A radio-degradation pathway of FA is also discussed. © 2015 Elsevier Ltd.

Le Grandois J.,Institute technique agro industriel | Ruas M.,University of Strasbourg | Kalisa P.,Institute technique agro industriel | Jolissaint M.,University of Strasbourg | And 4 more authors.
LWT - Food Science and Technology | Year: 2013

DNA damage in frozen and chilled salmon (Salmo salar) was investigated using the comet assay. Frozen salmon was thawed at 10°C and chilled salmon was kept in flake ice, mimicking a thermal abuse and an extended storage, respectively. Electrophoresis conditions were as follows: a second layer of low-melting-point agarose at 1g/100mL; a voltage of 2.5Vcm-1; and running time of 1.0min. Control cells showed relatively round shaped comets with a large and intense head, and a short tail. Their olive tail moment (OTM) profiles showed a predominance of low values that were narrowly distributed (between 8 and 25). As thawing or chill storage progressed, comets showed an increase in tail size, a shift of intensity from the head to the tail and a clear separation between the two. This was associated with a shift of OTMs towardhigher values and a wider distribution of these values: between 17 and 43 after 42h of thawing; and between 12 and 46 after 12 days of chill storage. Based on OTM values and their distribution, the DNA damage in salmon cells was visible for frozen salmon after 3h of thawing at 10°C and for chilled salmon after 9 days of storage. © 2013 Elsevier Ltd.

Delchier N.,French National Institute for Agricultural Research | Delchier N.,University of Avignon | Ringling C.,TU Munich | Le Grandois J.,Institute technique agro industriel | And 6 more authors.
Food Chemistry | Year: 2013

Folates are described to be sensitive to different physical parameters such as heat, light, pH and leaching. Most studies on folates degradation during processing or cooking treatments were carried out on model solutions or vegetables only with thermal treatments. Our aim was to identify which steps were involved in folates loss in industrial processing chains, and which mechanisms were underlying these losses. For this, the folates contents were monitored along an industrial canning chain of green beans and along an industrial freezing chain of spinach. Folates contents decreased significantly by 25% during the washing step for spinach in the freezing process, and by 30% in the green beans canning process after sterilisation, with 20% of the initial amount being transferred into the covering liquid. The main mechanism involved in folate loss during both canning green beans and freezing spinach was leaching. Limiting the contact between vegetables and water or using steaming seems to be an adequate measure to limit folates losses during processing. © 2013 Elsevier Ltd. All rights reserved.

Martin H.,Fougeres Laboratory | Soumet C.,Fougeres Laboratory | Fresnel R.,Fougeres Laboratory | Morin T.,Institute technique agro industriel | And 5 more authors.
Journal of Applied Microbiology | Year: 2013

Aims: The virucidal activity of peroxy-products was evaluated and compared with sodium hypochlorite using the EN 14675 European suspension test and a surface test developed in our laboratory. The classical approach on infectivity of viruses was complemented with a prospective approach on virus genomes. Methods and Results: Both infectivity tests were adapted and/or developed to determine the activity of disinfectants against reference bovine enterovirus type 1 [enteric cytopathogenic bovine orphan virus (ECBO)] and resistant hepatitis A virus (HAV) in conditions simulating practical use. Similar concentrations of active chlorine were virucidal against both viruses, either at 0·062% using the suspension test or at 0·50-1% using the surface test. However, for potassium monopersulfate and peracetic acid products, concentrations of approximately three times (3%) to 72 times (9%) higher were necessary against HAV than ECBO when determined with the suspension test. With the surface test, 4-8% peroxy-products were virucidal against HAV, either 16 times more peroxy-products concentrations than against ECBO. No significant impact on the targeted area of the viral genome measured by real-time RT-PCRs was obtained for ECBO and HAV suspensions treated with disinfectants, even with doses higher than the minimal virucidal concentrations. Conclusions: Sodium hypochlorite, but not peroxy-products, had similar activity against ECBO and HAV. No relation could be established between infectivity tests and genome destruction. Significance and Impact of the Study: This is the first comparative study that investigates with novel suspension and surface tests the reduction of infectivity and genome destruction of two resistant viruses by peroxy-compounds. The results and conclusions collected with European standards are discussed. © 2013 The Society for Applied Microbiology.

Augustin J.-C.,National Veterinary School of Alfort | Ferrier R.,National Veterinary School of Alfort | Ferrier R.,Institute technique agro industriel | Hezard B.,Institute technique agro industriel | And 2 more authors.
Food Microbiology | Year: 2014

Individual-based modeling (IBM) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few Listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. The IBM approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °C. These results confirmed similar observations obtained with smear soft cheese (Ferrier et al., 2013). These two different food models were used to compare the IBM/microscale and population/macroscale modeling approaches in more global exposure and risk assessment frameworks taking into account the variability and/or the uncertainty of the factors influencing the growth of L. monocytogenes. We observed that the traditional population models significantly overestimate exposure and risk estimates in comparison to IBM approach when contamination of foods occurs with a low number of cells (<100 per serving). Moreover, the exposure estimates obtained with the population model were characterized by a great uncertainty. The overestimation was mainly linked to the ability of IBM to predict no growth situations rather than the consideration of microscale environment. On the other hand, when the aim of quantitative risk assessment studies is only to assess the relative impact of changes in control measures affecting the growth of foodborne bacteria, the two modeling approach gave similar results and the simplest population approach was suitable. © 2014 Elsevier Ltd. All rights reserved.

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