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Abstract: The cook-chill operation, a widely used process within central cooking facilities, implies that cooked dishes have to be quickly cooled down immediately after cooking in order to prevent any food-borne diseases due to Clostridium perfringens. The food service operators are obliged to validate the efficiency of the cooling process in the context of their HACCP plan. To perform this cooling process, they can either ensure compliance with some reference criterion (maximal cooling duration) or demonstrate that the cooling operation is safe by carrying out prior tests. This document presents an experimental method to validate the sanitary efficiency of the cooling process. In the studied kitchen the food was cooked and, successively, distributed into plastic containers, cooled down in blast-chiller and then stored in cold room. The tests consisted in monitoring food temperature at the center of the containers from the end of cooking until the beginning of cold room storage. The measurements were performed during 6 cycles of food preparation. From the monitored time–temperature profiles, thermal cooling equations were established for modeling. Each parameter of these thermal equations was linked with a distribution fitted with the experimental data. Then these thermal equations were coupled with predictive microbiology equations. A probabilistic calculation of the C. perfringens potential growth was carried out by using @Risk software. The proposed method required only simple monitoring equipments and could be easily implemented in central kitchens under the usual working conditions. The cooling conditions in the studied kitchen could be considered as satisfactory because the calculations give only a 0.4% probability that the C. perfringens potential growth was equal or greater than 1 log10 cfu/g. [Copyright &y& Elsevier]

Abstract: Cooked dishes must be cooled rapidly after cooking to avoid significant growth of Clostridium perfringens. French regulations require that produce be cooled from 63 °C to 10 °C in less than 2 h. Cooling is a critical phase for central cooking facilities that need to cool large quantities of food. The food is cooled in blast-chillers before being placed in cold storage. We observed that in France the blast-chiller is usually switched off by operators as soon as a measured temperature is equal to or below 10 °C. This temperature measurement may be taken at any place in the batch. We studied the consequences of this procedure on the distribution of temperatures at the time when cooling is stopped. We did this by monitoring the core temperatures of the foodstuffs during 52 cooling operations carried out in seven central cooking facilities for hospitals or schools. The data allowed us to estimate the characteristics of the distribution of temperatures within batches. Simulations suggest that, when the blast-chiller is switched off after cooling, there can be significant differences between random temperature readings in the batch and the highest temperatures. For 5% of simulations, the difference could be greater than 17 °C. We propose alternative rules to reduce this discrepancy. If such a single measurement was replaced by three measurements, with each of them taken at the centre of a container, this difference would be less than 3.8 °C in 95% of the simulations. The improvement of methods for measuring temperatures is necessary to achieve the cooling durations recommended by the official organizations. [Copyright &y& Elsevier]

Cemented carbide parts have been manufactured from WC-12Co granules by "Solvent on Granules 3D-Printing" and compared with reference parts produced by conventional press and sintering. SG-3DP consists in growing a green part layer-by-layer by selective solvent jetting on powder-polymer granule beds. Both 3D printed green parts and uniaxially pressed compacts have been consolidated by thermal debinding and liquid phase sintering. Further densification has been achieved by hot isostatic pressing. 3D-printed parts subjected to hot isostatic pressing exhibit 99.9% of theoretical density, 1308 ± 10 HV30 hardness and 12.1 ± 0.3 MPa∙m½ indentation toughness, which are comparable to properties of a commercial fine grained WC-12Co. Percussion drilling tests with fully dense SG-3DP drill plates have also been carried out successfully on concrete. • Solvent on granules 3D-printing" (SG-3DP) is an effective Additive Manufacturing route to produce hard metal parts. • Fully dense WC-12Co parts successfully processed by SG-3DP technique followed by Hot isostatic pressing. • 3D-printed part microstructure equivalent to press and sintering microstructures. • 3D-printed drill bits show good shape retention and B04 porosity. • Functional parts processed and successful percussion drilling tests performed. [ABSTRACT FROM AUTHOR]

Titanium parts are produced by the "Solvent on granules 3D-Printing" technique (SG-3DP). Angular Titanium Hydride powders are used. A special purpose table-top machine, designed and built in a previous development, is used to print green parts, which are subsequently debinded, dehydrided and sintered in a muffle furnace. Porous electrode plates are produced with and without hole grids. The parts exhibit good shape preservation, with open interconnected porosities between 55 and 59%. The microstructure is characterized by optical metallography and scanning electron microscopy. In addition, experimental watch cases have been successfully printed and sintered. The results show the feasibility of using hydride powder for 3D-Printing of complex parts with good shape preservation. • "Solvent on granules 3D-Printing" is an effective Additive Manufacturing route to produce titanium parts from titanium hydride powder • Granules prepared from angularTiH2 powder • 3D-printed porous parts (open porosity of interest for electrolyser plates) • Complex watch case shows good shape retention after debinding, dehydriding and sintering [ABSTRACT FROM AUTHOR]

Tungsten cemented carbide parts have been produced by the "Solvent on Granule" 3D-Printing technique. It consists in growing layer-by-layer a green part by spreading a powder-polymer granule bed, followed by selective solvent jetting, and layer consolidation after solvent evaporation. The granules are prepared by wet blending, drying, milling and sieving to appropriate size range. The printed green parts are consolidated by thermal debinding and liquid phase sintering. Fully dense WC-Co test parts and a drill bit have been produced from presintered powder and elementary Co powder. The microstructures are equivalent to those of press and sintered parts. Good shape retention and tolerances are achieved. • « Solvent on granule » 3D-printing is an effective Additive Manufacturing route to produce hard metal parts • Granules prepared from presintered WC-Co powder and additional elementary Co • 3D-printed dense WC-17.7Co parts • 3D-printed part microstructure equivalent to press and sintering microstructures • Complex 3D-printed drill bit shows good shape retention and porosity less than A04 [ABSTRACT FROM AUTHOR]

Little is known about the interaction of nanoparticles (NPs) with soil constituents and their effects in plants. Boron (B), an essential micronutrient that reduces crop production at both deficiency and excess, has not been investigated with respect to its interaction with cerium oxide NPs (nano-CeO 2 ). Considering conflicting results on the nano-CeO 2 toxicity and protective role as antioxidant, their possible modulation on B toxicity in sunflower ( Helianthus annuus L.) was investigated. Sunflower was cultivated for 30 days in garden pots containing original or B-spiked soil amended with nano-CeO 2 at 0–800 mg kg −1 . At harvest, Ce and B concentrations in tissues, biomass, and activities of stress enzymes in leaves were determined. Results showed that in the original soil, Ce accumulated mainly in roots, with little translocation to stems and leaves, while reduced root Ce was observed in plants from B-spiked soil. In the original soil, higher levels of nano-CeO 2 reduced plant B concentration. Although morphological effects were not visible, changes in biomass and oxidative stress response were observed. Sunflower leaves from B-spiked soil showed visible symptoms of B toxicity, such as necrosis and chlorosis in old leaves, as well as an increase of superoxide dismutase (SOD) activity. However, at high nano-CeO 2 level, SOD activity decreased reaching values similar to that of the control. This study has shown that nano-CeO 2 reduced both the B nutritional status of sunflower in original soil and the B phytotoxicity in B-spiked soil. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to assess the temperature conditions in neonatal care units for the preparation and storage of infant milk formula (IMF) and infant feeding using bottles and continuous feeding syringes. Enterobacter sakazakii in IMF for feeding infants has been chosen as the subject of this study because of the high risk incurred by IMF manufacture without total microbial destruction and the high sensitivity and mortality rates of this population group. From IMF preparation till neonate feeding, time–temperature profiles of IMF samples were monitored and analysed. In order to show the health impact of this data, potential E. sakazakii growth was calculated. As IMF can be also contaminated with Salmonella, potential Salmonella growth was also calculated. However potential E. sakazakii growth data were only analysed because of E. sakazakii and Salmonella spp. data being close. The study of 25 neonatal care units in 15 hospitals showed that the final potential growth for bottles depended on different parameters: initial water temperature, room temperature where IMF was prepared, cold storage temperature and time, reheating temperature and time. One parameter was not usually enough to determine the final growth increment alone and a well-controlled and high performance stage could result in an incorrect food safety indication if the other stages are less effective. On the other hand, the final potential growth for the continuous feeding syringes depended mainly on the feeding period since the IMF was kept in a particularly high ambient air temperature (≈25°C) in the infant’s bedroom. This stage would be controlled first (with a cold syringe cover for example); then, as for bottles, the other stages would be controlled to result in a correct food safety indication. [Copyright &y& Elsevier]

Abstract: Clostridium perfringens is responsible for foodborne diseases often associated with processed meats in institutions. This study investigated the behavior of C. perfringens in beef-in-sauce products in a French hospital. In the studied process, the final reheating step makes the inactivation of C. perfringens vegetative cells possible. The aim of this study was thus to combine microbial, thermal and dose response modeling to propose, for this reheating step, three new control measures which are as efficient as current French regulation while also being easier to apply. These measures were based on thermal process duration (DA53), final temperature in food (FTF) and sum of temperatures-minutes above 53 °C (ST53) required to achieve food safety. A criterion was defined to describe the ability of the proposed control measures to lower the risk of foodborne illness related to the consumption of products with high populations of C. perfringens vegetative cells before reheating. To estimate acceptable values of DA53, FTF and ST53, variability and uncertainty were taken into account separately. A two dimensional Monte Carlo simulation enabled the definition of 14 measure thresholds which made sure with a 97.5% confidence that less than 20%, 10% or 5% of exposed consumers in a specified population would experience diarrhea. The three proposed control measures, single and combined, were then compared by estimating the duration required to reach control measure thresholds. This required duration differs significantly from a control measure to the other, with the lowest duration for the combination of FTF and DA53. [Copyright &y& Elsevier]

Abstract: Our aim was to determine factors that have an impact on the bacterial load of inner surfaces of food refrigeration equipment to develop recommendations that should be made to consumers. We investigated 23 domestic refrigerators (DRs) and, for comparison, six serve-over counters (SOCs). Several zones were studied for aerobic mesophilic counts (AMC) presumptive Bacillus cereus and coagulase-positive staphylococci. In addition, for each DR sample, we collected data on the condition of the sampled surface and refrigeration practices. In DRs, there was no correlation between AMC and temperature, relative humidity, pH or cleaning frequency. AMC counts in SOCs, which are cleaned and disinfected weekly, were similar to the figures from the less frequently cleaned DRs, but B. cereus and coagulase-positive Staphylococus were less frequently found in SOCs. In DRs, the highest AMC counts were reached when both condensation and food traces were visible, i.e. when growth conditions were met, resulting in a mean of 104 CFU/cm2 against of mean of 32 CFU/cm2 on clean surfaces and dry surfaces with food traces. Consequently, two recommendations for consumers are (1) to avoid condensation and (2) to clean up food spills as soon as possible. [Copyright &y& Elsevier]

Abstract: This paper sets out a bacterial hazard analysis methodology, based on the ISO 22000 standard, which could be adopted by small food manufacturers. The paper provides a practical example: meat pâté prepared by pork butchers. The results of the hazard analysis showed that many bacterial hazards, particularly Listeria monocytogenes, Salmonella and Staphylococcus aureus could be effectively controlled by good hygiene practices. For three microbial hazards –Bacillus cereus, Clostridium botulinum and Clostridium perfringens – specific control measures must be implemented. Hazard analysis provided the necessary basis for a rational choice of these specific control measures. [Copyright &y& Elsevier]

Abstract: We prepared a Mg-2 mass % multiwall carbon nanotubes composite employing a powder metallurgy technique. The kinetics of hydrogen absorption/desorption of the as-synthesized composite was much faster than that of reference samples of pure Mg. The pressure-composition isotherm (measured at 300 °C) of the as-synthesized composite exhibited no measurable pressure hysteresis, with the equilibrium hydrogen pressures in the plateau region being higher than those of pure Mg by a factor of up to 1.8. Equal channel angular pressing of the as-synthesized composite led to a slow down of the absorption/desorption processes at the initial stages of the processes, and to their acceleration at the later stages. We suggested that the mechanism responsible for the good kinetic performance of the as-synthesized composite was fast diffusion of hydrogen through the cores of carbon nanotubes. We put forward a hypothesis relating the increase in equilibrium hydrogen pressure in the as-synthesized composite to the elastic constraints imposed by carbon nanotubes on the Mg matrix. [Copyright &y& Elsevier]