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The present study aims to determine the carcinogenic and neurotoxic risks associated with acrylamide intake from cereal products. Analysis on a UPLC–MS/MS spectrometer revealed that oat-based and mixed cereals contain the highest amount of acrylamide among cereal products with levels as high as 271 and 348 μg/kg, respectively. Children were shown to exhibit both carcinogenic and neurotoxic risks regardless of the type of cereal product consumed. For adults above 50 years of age, only consumers of oat-based cereal products seem to exhibit carcinogenic and neurotoxic risks. To avoid a carcinogenic and neurotoxic risk among the Lebanese population, we propose that food processors set the maximum tolerable concentration for acrylamide in cereal products at 94.8 μg/kg product, a value which is threefolds lower than the average acrylamide levels found in this study. Alternatively, and unreasonably, the average Lebanese population and children among the Lebanese population may choose to cut down on cereal consumption by 1.7- and 7.2-folds respectively, should they want to avoid a health hazard as a result of acrylamide intake. The industry should also respond by optimizing the production process in a way to reduce acrylamide levels in cereals. more...

The present work investigates the energy consumption and yield of the esterification reaction of free fatty acids (waste oil pretreatment) under a simultaneous water removal by adsorption. The reaction was performed under methanol, ethanol, and 1-propanol at the optimum reaction temperature of 100°C. The higher boiling point temperature of 1-propanol reduced the energy requirement of the reaction by 36.3 and 34.4% compared to methanol and ethanol, respectively. Moreover, despite the higher reactivity associated with alcohols having lower carbon chains, the reaction yield was approximately 16.4% higher under 1-propanol than the other two alcohols. This can be ascribed to the ability to use higher amounts of 1-propanol while maintaining lower energy consumption. The results also indicated that the reaction at 100°C under methanol and ethanol had a similar energy consumption and yield, favoring the use of the renewable ethanol over the widely used nonrenewable methanol. Finally, these findings highli... more...

The properties of nickel nanoparticles inside the mesopores of SBA-15 support were tuned by a careful control of the calcination rate. Ni/SBA-15 catalysts containing 5 wt% nickel were prepared following three different calcination rate values (0.25 −0.5 −4.5 °C min −1 ). Their properties were characterized by N 2 -sorption, X-ray diffraction (low and wide angles), temperature programed reduction and transmission electron microscopy. These catalysts were then tested in dry reforming of methane (DRM). As a result, the catalyst calcined at 0.5 °C min −1 resulted in the formation of strong interaction between the active phase and the SBA-15 support, high nickel dispersion and accessibility that greatly enhanced its stability in dry reforming of methane. more...

ZSM5 zeolite was impregnated with different KOH loadings (15 wt.%, 25 wt.% and 35 wt.%) to prepare a series of KOH/ZSM5 catalysts. The catalysts were calcined at 500 °C for 3 h and then characterized by N2 adsorption–desorption and X-ray diffraction (XRD) techniques. The catalysts were tested in the transesterification reaction in a batch reactor at 60 °C and under atmospheric pressure. It was found that KOH/ZSM5 with 35 wt.% loading showed the best catalytic performance. The best reaction conditions in the presence of KOH/ZSM5 (35 wt.%) were determined while modifying the catalyst to oil ratio and the reaction time. The highest methyl ester yield (>95%) was obtained for a reaction time of 24 h, a catalyst to oil ratio of 18 wt.%, and a methanol to oil molar ratio of 12:1. The properties of produced biodiesel complied with the ASTM specifications. The catalytic stability test showed that 35KOH/ZSM5 was stable for 3 consecutive runs. Characterization of the spent catalyst indicated that a slight deactivation might be due to the leaching of potassium oxides active sites. more...

The present study aims to quantify acrylamide in caffeinated beverages including American coffee, Lebanese coffee, espresso, instant coffee and hot chocolate, and to determine their carcinogenic and neurotoxic risks. A survey was carried for this purpose whereby 78% of the Lebanese population was found to consume at least one type of caffeinated beverages. Gas Chromatography Mass Spectrometry analysis revealed that the average acrylamide level in caffeinated beverages is 29,176 μg/kg sample. The daily consumption of acrylamide from Lebanese coffee (10.9 μg/kg-bw/day), hot chocolate (1.2 μg/kg-bw/day) and Espresso (7.4 μg/kg-bw/day) was found to be higher than the risk intake for carcinogenicity and neurotoxicity as set by World Health Organization (WHO; 0.3–2 μg/kg-bw/day) at both the mean (average consumers) and high (high consumers) dietary exposures. On the other hand, American coffee (0.37 μg/kg-bw/day) was shown to pose no carcinogenic or neurotoxic risks among the Lebanese community for consumers with a mean dietary exposure. The study shows alarming results that call for regulating the caffeinated product industry by setting legislations and standard protocols for product preparation in order to limit the acrylamide content and protect consumers. In order to avoid carcinogenic and neurotoxic risks, we propose that WHO/FAO set acrylamide levels in caffeinated beverages to 7000 μg acrylamide/kg sample, a value which is 4-folds lower than the average acrylamide levels of 29,176 μg/kg sample found in caffeinated beverages sold in the Lebanese market. Alternatively, consumers of caffeinated products, especially Lebanese coffee and espresso, would have to lower their daily consumption to 0.3–0.4 cups/day. more...

The batch fermentation process, inoculated by Pulsed Electric Field (PEF) treated wine yeasts (Saccharomyces cerevisiae Actiflore F33), was studied. PEF treatment was applied to the aqueous yeast suspensions ([Y] = 0.012 g/L) at the electric field strengths of E = 100 and 6000 V/cm using the same treatment protocol (number of pulses n = 1000, pulse duration ti = 100 μs, and pulse repetition time Δt = 100 ms). Electrical conductivity was increasing during and after the PEF treatment, which reflected cell electroporation. Then, fermentation was run for 150 h in an incubator (30 °C) with synchronic agitation. Electro-stimulation was revealing itself by the improvement of fermentation characteristics, and thus increased yeast metabolism. At the end of the lag phase (t = 40 h), fructose consumption in samples with electrically activated inoculum exceeded that of the control samples by ≈ 2.33 times for E = 100 V/cm and by ≈ 3.98 for E = 6000 V/cm. At the end of the log phase (120 h of fermentation), ≈ 30% mass reduction was reached in samples with PEF-treated inocula (E = 6000 V/cm), whereas the same mass reduction of the control sample required approximately 20 extra hours of fermentation. more...

Ni7.5/NaY catalysts were prepared using two different methods, the incipient wetness impregnation method and the “two-solvent” method. These catalysts were characterised by N2 sorption, XRD, TEM and TPR. Their activity and stability in the dry reforming of methane were tested at atmospheric pressure under an equimolar mixture of methane and carbon dioxide. Three different Ni species, very small, spherical, and layers of nickel silicate were observed by TEM. The preparation by the two-solvent method led to a better dispersion of the active phase as well as to better activity and stability. These catalysts were promoted with small amounts (0.1 wt%) of rhodium. Rhodium facilitates the reducibility and greatly enhances catalytic activity. A complete conversion (100%) for CH4 and CO2 over the Rh promoted catalyst is achieved at 584 °C and 559 °C respectively, while for the non-promoted Ni7.5/NaY catalyst, only a 60% conversion rate for CH4 and CO2 is reached at the same temperatures. more...

A B S T R A C T Different cobalt loadings (3, 6, 12, 24 wt%) were impregnated using the double-solvent technique on SBA-15 calcined at 500 8C presenting a high specific surface area. The impregnated solids were stabilized at 450 8C in the air. The impregnation of cobalt led to the incorporation of cobalt oxide nanoparticles in the mesoporosity of the SBA-15. The cobalt nanoparticles were easily reducible compared to similar solids prepared by different methods. The presence of these nanoparticles enhanced significantly the reactivity of the catalysts in the considered reaction. The addition of more than 12 wt% of cobalt did not enhance the catalytic reactivity due to the deposition of cobalt oxide species on the surface of the support. The cobalt-impregnated solids are efficient in decreasing the oxidation temperature of different probe molecules and are totally selective towards the formation of CO2 and H2O. more...

The catalysts in this study were prepared via the “two-solvents” impregnation method and labeled as: x Co and y Ru- x Co/SBA-15 ( x = 12 wt%, y = 0.75–1.125–1.5 wt%). These catalysts were characterized by N 2 sorption, X-Ray Diffraction (XRD) techniques, Transmission Electron Microscopy (TEM) analyses and Temperature Programmed Oxidation/Reduction (TPO/TPR). The catalytic activity of mono (Co) and bimetallic (Co–Ru) supported on SBA-15 was investigated in the dry reforming of methane (DRM) reaction. TEM and XRD data showed that Ruthenium species were mainly located outside the porosity of the support, while cobalt species were present inside and outside the pores. The addition of ruthenium promoted the reducibility of cobalt catalysts to lower temperatures and a complete reduction of the Ru–Co/SBA-15 catalysts at T T = 250 °C. more...

International audience; Two silica supports either non porous (SiO2) or mesoporous (SBA-15) were impregnated with cobalt (12 wt%) in order to study the confinement effect on catalytic performances in dry reforming of methane. Further increase of activity was obtained by adding small amounts of rhodium (0.2 and 0.5 wt%) to the Co/SBA-15 catalyst. The structural and morphological properties of the calcined samples were characterized by N2 sorption, X-ray diffraction and high-resolution transmission electron microscopy (ultra-thin sections). Their reducibility was studied by temperature-programmed reduction. After in situ reduction of the materials, their catalytic activity was tested in dry reforming of methane up to 800 °C followed by stability testing at 550 °C for 550 minutes. Cobalt confinement in the mesopores of SBA-15 is shown to be highly beneficial towards not only activity but also stability, the reduced nanoparticles being then more resistant against sintering under stream. Rh plays a role as an additional active phase. It also strongly favors cobalt stabilization in the mesopores by permitting its reduction at a much lower temperature, which allows avoiding metal migration to the surface of the silica grains. The nature of coke is also shown to depend on rhodium addition, with less amount of carbon gamma (graphitic and destructive form) formed on the Rh-containing sample compared to the Rh-free Co/SBA-15 catalyst. more...

International audience; The effect of Rh addition on the catalytic performance of Ni/SBA-15 catalysts was studied in the dry reforming of methane. The SBA-15 silica support was synthesized in large quantities and the metals were deposited using the two solvents impregnation method. The properties of the calcined, reduced and spent catalysts were studied using the N2 sorption isotherms, XRD, H2-TPR, SEM, TEM and Raman spectroscopy. It was shown that the SBA-15 porous structure was maintained throughout the study with high dispersion of the metals inside the pores. The Ni/SBA-15 catalyst was stable for more than 90h of testing owing to the porous structure of the support that stabilizes the particles and prevents their sintering; thus the promotion with 0.5 wt% Rh showed a minor improvement of the catalytic stability. The 0.5Rh-Ni/SBA-15 catalyst was also stable at 650°C and 9 bars for more than 200 min. more...

International audience; A low weight % of Ni (5 wt %) and the two solvents technique of deposition are used to obtain well-dispersed Ni-species (either particles or species dispersed on the silica surface) and avoid the formation of large particles on three silicas SBA-15, Aerosil 300 and diatoms MN3. Stability tests at 650°C for valorization of methane obtained from natural or shale gas: methane dry reforming and at 800°C for bireforming are compared. For bireforming (steady state, 800°C, 10 h, CH4/CO2/H2O 1:0.4:0.8, 62,700 ml.g-1.h-1), an unexpected stability of Ni/Aerosil silica is observed and tentatively associated with the pretreatment applied to silica more...

ZSM5 supported nickel (Ni/ZSM5) and cobalt (Co/ZSM5) catalysts with a 7 wt.% total metal loading were prepared by the wet impregnation method. The CO 2 reforming of methane reaction was carried out in the 600 to 800°C temperature range at a gas hourly space velocity GHSV = 60000 mL.g−1.hr−1. Above 650°C, methane and carbon dioxide conversions were slightly higher over the Co/ZSM5 solid. During the dry reforming reaction, a large amount of carbon (46.4 wt.%) was deposited on the Ni/ZSM5 catalyst relatively to the small amount (3.6 wt.%) found in the Co/ZSM5 catalyst. Different carbonaceous species were identified in the spent Ni/ZSM5 solid. The X-ray diffraction spectra revealed that some graphitic carbon was deposited on the Ni/ZSM5 catalyst while such carbon species were absent in the Co/ZSM5 catalyst. more...

Catalysts prepared using three dimensional SBA-16 silica support (composed of micropores and cage-like mesopores) were tested in the reaction of methane dry reforming, in comparison with 2D hexagonal mesoporous SBA-15 support. The samples were evaluated by N2 sorption and X-Ray diffraction (XRD) for the assessment of their textural and structural properties. The reducibility was characterized by temperature programmed reduction (TPR). The catalytic performances were evaluated in methane dry reforming and spent catalysts (after reaction) were characterized for the evaluation of sintering and coke formation by TPH/MS, XRD and HR-TEM. more...

Invasive aspergillosis (IA) is a life-threatening infection in severely immunocompromised haematological malignancy patients. In this study, the efficacy and safety of caspofungin, voriconazole or the combination as primary and salvage therapy in patients with IA were compared. The study included 181 patients with haematological malignancies and IA who received primary or salvage therapy with caspofungin, voriconazole or the combination. In total, 138 patients who received treatment for ≥7 days were analysed; 86 underwent primary antifungal therapy (15 with caspofungin, 38 with voriconazole and 33 with both). Among the salvage therapy patients, 17 received caspofungin, 24 received voriconazole and 35 received both. In the primary therapy group, no difference in therapy response was found, but caspofungin was associated with higher IA mortality rates. A multivariate competing risk analysis of primary antifungal therapy revealed that voriconazole was independently associated with lower IA-associated mortality rates than caspofungin (hazard ratio=0.2, 95% confidence interval 0.06-0.96; P=0.04). In the salvage therapy group, the three treatment groups had similar responses and IA-associated mortality rates. The combination of voriconazole and caspofungin did not result in better outcomes compared with voriconazole alone, as primary or salvage therapy, in haematological malignancy patients. However, voriconazole was associated with a lower Aspergillus-associated mortality rate compared with caspofungin monotherapy. more...

International audience; ZSM-5/SBA-15 composites with high textural properties were synthesised by a microwave-assisted zeolitisation of Al-SBA-15 in the presence of tetrapropylammonium bromide. The effect of the hydrothermal treatment temperature and of ammonium fluoride, often used as a catalyst, was studied. Resulting materials were characterised by XRD, SEM, N2 sorption, HR-TEM, hyperpolarised Xe NMR, pyridine sorption as well as by their stability toward boiling water. It was shown that the hydrothermal synthesis has to be carried out at 140 °C in order to better preserve the structure of the mesoporous precursor. Composite materials could be obtained only from a fluoride-free synthesis at short crystallisation times, t < 5 h. Appearance of 2-5 nm nanoparticles in some of the corresponding samples, has been related to the increase in the total acidity. Inclusion of zeolitic material in the remaining Al-SBA-15 structure was demonstrated by hyperpolarised xenon NMR studies. more...

The aim of this work was to study the efficiency of inactivation of Escherichia coli cells in aqueous suspensions using combined moderate pulsed electric field (PEF) and thermal treatments. The inactivation kinetics of E. coli cells in aqueous suspensions (1 wt%) was monitored using conductometric technique. The electric field strength E was within 5-7.5 kV/cm, the effective PEF treatment time was within 0-0.75 s, the pulse duration ti was within 0.3-1 ms, the medium temperature was 30-50°C, and the time of thermal treatment tT was within 0-7000 s. The organic acid concentration was within 0-0.5 g/L.The damage of E. coli was accompanied by release of intracellular components. The synergy between the PEF and thermal treatments in E. coli inactivation was clearly demonstrated. The damage efficiency was noticeably improved by addition of organic acids, especially lactic acid. more...

This work discusses pulsed electric fields (PEF) induced effects in treatment of aqueous suspensions of concentrated yeast cells (S. cerevisiae). The PEF treatment was done using pulses of near-rectangular shape, electric field strength was within E = 2 – 5 kV / cm and the total time of treatment was t PEF = 10 −4 – 0.1 s . The concentration of aqueous yeast suspensions was in the interval of C Y = 0 – 22 (wt%), where 1% concentration corresponds to the cellular density of 2 × 10 8 cells / mL . Triton X-100 was used for studying non-ionic surfactant additive effects. The electric current peak value I was measured during each pulse application, and from these data the electrical conductivity σ was estimated. The PEF-induced damage results in increase of σ with t PEF increasing and attains its saturation level σ ≈ σ max at long time of PEF treatment. The value of σ max reflects the efficiency of damage. The reduced efficiency of damage at suspension volume concentration higher than φ Y ≈ 32 vol% is explained by the percolation phenomenon in the randomly packed suspension of near-spherical cells. The higher cytoplasmic ions leakage was observed in presence of surfactant. Experiments were carried out in the static and continuous flow treatment chambers in order to reveal the effects of mixing in PEF-treatment efficiency. A noticeable aggregation of the yeast cells was observed in the static flow chamber during the PEF treatment, while aggregation was not so pronounced in the continuous flow chamber. The nature of the enhanced aggregation under the PEF treatment was revealed by the ζ-potential measurements: these data demonstrate different ζ-potential signs for alive and dead cells. The effect of the electric field strength on the PEF-induced extraction of the intracellular components of S. cerevisiae is discussed. more...