Residues of lead,cadmium, mercury and tin in canned meat products from Egypt: an emphasis on permissible limits and sources of contamination

In an attempt to determine the residual levels of lead (Pb), cadmium (Cd), mercury (Hg) and tin (Sn) in canned meat products marketed in Egypt, a total number of 160 random samples (40 each) of canned chicken luncheon (CCL), canned beef luncheon (CBL), canned frankfurter (CF) and canned corned beef (CCB) were randomly collected from different supermarkets in Egypt to be analyzed using atomic absorption spectrophotometry. From the obtained results, it was found that the mean values of residual levels of Pb in examined CCL, CBL, CF and CCB samples were 0.330, 0.224, 0.206 and 0.334 mg/kg, respectively, while those of Cd were 0.057, 0.053, 0.039 and 0.042 mg/kg, those of Hg were 0.387, 0.450, 0.402 and 0.332 mg/kg, and finally those of Sn were 2.061, 2.308, 0.755 and 1.997 mg/kg. The obtained results were compared with the permissible limits of heavy metals recommended by international and national authorities. In addition, the public health significance as well as the sources of contamination of canned meat products by heavy metals were addressed.     

Effect of Germination on the Functional and Moisture Sorption Properties of High–Pressure-Processed Foxtail Millet Grain Flour

Foxtail millet is one of the commonly cultivated, nutritionally competitive source of protein, fibre, phytochemicals and other micronutrients, as compared to major cereals like wheat and rice. Considering the potential of these grains, the high pressure processed flours of germinated (GFMF) and non-germinated foxtail millet (NGFMF) grains were studied for its functional, moisture sorption and thermodynamic properties. Germination and high-pressure processing of foxtail millet grains significantly improved the functional properties of the flour. Apart from this, the moisture sorption isotherms of both the flours were determined at 10, 25 and 40 °C and the sorption data was fitted to Guggenheim-Anderson-De Boer (GAB) sorption model. The monolayer moisture content for NGFMF and GFMF ranged between 3.235–2.364 and 2.987–2.063 g g^?1, respectively. The isosteric heat of sorption ranged between ? 76.35 to ? 38.23 kJ mol^?1 for NGFMF and 172.55 to ? 34.02 kJ mol^?1 for GFMF at a moisture range of 0 to 36%, whereas, the integral entropy of sorption for NGFMF ranged between ? 0.404 and ? 0.120 kJ mol^?1 K^?1 and for GFMF between ? 0.667 and ? 0.383 kJ mol^?1 K^?1. Along with the validation of the compensation theory, the values of spreading pressures lied in the range of 0–0.078 J m^?2 for NGFMF and 0– 0.124 J m^?2 for GFMF, while, the glass transition temperatures ranged between 82.25 and 28.67 °C for NGFMF and from 51.11 to 11.83 °C for GFMF at all three temperatures.     

Enhancement of Bioactive Compounds and Antioxidant Activities of Olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) Leaf Extract by Instant Controlled Pressure Drop

In this work, the effect of Détente Instantanée Contrôlée (DIC) (French for instant controlled pressure drop) on the total polyphenol, flavonoids, α-tocopherol contents, and antioxidant activities of olive leaves was studied. Olive leaf extracts were pre-treated at one cycle DIC under 0.1 MPa pressure for 11 s and followed by an extraction with 95% ethanol at 55 °C during 3 h. The phenolic compounds, flavonoïds, oleuropein, and α-tocopherol contents were determined, showing 66.63 mg gallic acid equivalent (GAE)/g db, 12 mg catechin equivalent (CE)/g db, 43.9 mg/g db, and 0.15 mg/g db for the untreated leaves against 239.37 mg GAE/g db, 28 mg CE/g db, 70.3 mg/g db, and 0.59 mg/g db for DIC-treated leaves, respectively. Therefore, DIC allows more availability of bioactive compounds contributing to a high antiradical activity (DPPH) compared to a synthetic antioxidant butylated hydroxytoluene (BHT). Both extracts showed a total antioxidant capacity (method of phosphomolybdenum) greater than that of the standard BHT. Likewise, both extracts have a reducing power (FRAP test) significant concentration-dependent. The DIC-treated leaves showed a higher antioxidant capacity compared to that of untreated leaves. Thus, DIC could be an effective treatment to promote the extraction of bioactive molecules of high antioxidant activities from olive leaves.     

Design and in vitro evaluation of polymeric formulae of simvastatin for local bone induction

Simvastatin (SVS), a cholesterol-lowering drug, has been shown to stimulate bone formation. This study deals with the design and in vitro evaluation of local delivery systems for simvastatin. They are intended to treat bony defects resulting from periodontitis or to induce osteogenesis around the titanium implants. Granules and gels were formulated using bioerodible/biocompatible polymers, namely hydroxypropylmethyl cellulose (H), sodium carboxymethyl cellulose (C), and chitosan (Ch). The in vitro release profiles and kinetics were evaluated and the swelling and/or erosion was monitored. Differential scanning calorimetry (DSC) and infrared (IR) were used to detect any SVS/polymer interactions that may affect drug release. The results revealed variable extents of controlled drug release from the designed formulae depending on the polymer nature. About 50% cumulative SVS was released from both H granules and gel formulae within 24 h and ∼66% and ∼88% from C granules and gel, respectively. Ch formulae exhibited ∼50% release from granules and ∼30% from gel.     

Development of the high performance magnesium based hydrogen storage alloy

Series of MgNi type alloys with Ti, Al, Zr, Pd and Co additive elements were synthesized by mechanical alloying and their electrochemical hydrogen storage characteristics were investigated. Systematical alloy designing indicated that Mg_0.80Ti_0.15Al_0.05Zr_0.05Ni_0.95 alloy has the best electrode performance. The atomic fractions in this alloy were believed to be optimum to get the reasonable amount of hydrogen storage with the improved cyclic stability. Titanium was estimated to enter into Mg(OH)₂ layer during the discharging process and make this barrier layer more penetrable by elemental hydrogen. Al and/or Al-oxides were predicted to dissolve selectively throughout the barrier hydroxide layer and thus reduce the stability of this layer. The main contribution of Zr was estimated to arise from its large atomic size that Zr atoms can create extra sites for the elemental hydrogen in the alloy structure. As the alloy charge transfer resistances decreased, the alloy retention rates increased. Improvement in the alloy capacity retaining rate was also closely related with the hydrogen diffusion coefficients in the alloy.     

Green Alternatives to Nitrates and Nitrites in Meat-based Products–A Review

Several food additives are added in food for their preservation to maintain the freshness of food (antioxidants) or to slow down or stop the growth of microorganisms (preservative agents). Nitrites and nitrates are used as preservative agents in meat. Nitrites give a smoked taste, a pinkish color in the meat and protect the consumers against the risk of bacterial deterioration. Their addition is however very limited as, in high dose, it can have risks on human health and the environment. Nitrites may also combine with secondary or tertiary amines to form N-nitroso derivatives. Certain N-nitroso compounds have been shown to produce cancers in a wide range of laboratory animals. Thus, alternatives of nitrates and nitrites are the object of numerous research studies. Alternatives, such as the addition of vitamins, fruits, chemicals products, natural products containing nitrite or spices, which have similar properties of nitrites, are in evaluation. In fact, spices are considered to have several organoleptic and anti-microbial properties which would be interesting to study. Several spices and combinations of spices are being progressively evaluated. This review discusses the sources of nitrites and nitrates, their use as additives in food products, their physicochemical properties, their negatives effects and the use of alternatives of nitrites and nitrates in preserving meat products.     

Evaluation of chitosan tripolyphosphate gel beads as bioadsorbents for iron in aqueous solution and in human blood in vitro

Nonimprinted and Fe³⁺ imprinted chitosan tripolyphosphate gel beads were prepared via physical gel formation. A method based on in situ crosslinking using ethylene glycol diglycidyl ether was developed to imprint the chitosan tripolyphosphate gels with Fe³⁺ ion without deteriorating the gel beads. The beads were characterized by FTIR, SEM, XRD, and DSC with respect to the chemical structure, surface morphology, crystallinity, and thermal behavior. Swelling kinetics and Fe³⁺ ion adsorption behavior from aqueous solution were studied. The Fe³⁺ imprinted and in situ crosslinked beads proved to be durable and effective adsorbents for Fe³⁺ in solution. The bead prepared by in situ crosslinking and in the presence of 10 mM template ion had an equilibrium iron adsorption capacity of 53.9 mg/g after 3-hour contact with 5 mM Fe³⁺ solution. The pros and cons of the beads as biomedical iron adsorbents were tested by evaluating their serum iron removal capacities from human blood. The preliminary tests carried out showed that Fe³⁺ imprinted beads were more effective in decreasing serum iron in human blood when compared to the nonimprinted beads. The decrease in serum iron level accompanied a parallel decrease in the hemoglobin level. The calcium level was also affected upon contact with the beads. The Fe³⁺ imprinted beads were less effective than the nonimprinted ones in decreasing the calcium level indicating selectivity towards iron containing species. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Edible Coating Effects on Fried Potato Balls

The effects of various treatments and frying times on some physical, chemical, and sensorial properties of potato balls coated with chickpea and wheat flour were studied. Potato balls were pre-dusted with chickpea flour (CF) or wheat flour (WF) as an initial coating which was followed by dipping into 0.1% xanthum gum solution as the second coating. The last coating was breading with 1:3 CF/WF, 1:1 CF/WF, and 3:1 CF/WF mixtures. Coated potato balls were fried at 185 °C for 5, 7, and 9 min. The pre-dusting materials, particularly the effect of CF, enhanced yield values and sensorial properties as well as increased adhesion degree as it decreased frying loss. Although, the breading materials raised the yield values compared to the control, the yield and moisture content values decreased with increasing frying time. Frying loss, fat absorption, penetrometer values, and texture values also increased. Results revealed that CF is suitable as a pre-dusting material, and 7 min was the more efficient frying time for coated potato balls.     

A sandwich-type DNA array platform for detection of GM targets in multiplex assay

Over the last decade, array detection has been developed to qualitatively assess the presence of genetically modified organisms (GMOs). To date, DNA array systems have the highest capabilities as a result of GMOs analysis. We describe the construction of an array platform in the sandwich hybridization format for the detection of transgenic promoter of Cauliflower mosaic virus (CaMV; p35S). Sequence-specific signal development has been achieved by a sandwich complex composed of a surface immobilized capture probe and a fluorescein-tagged signal probe, which are partially complementary to the p35S oligonucleotide. We used poly-l-lysine-coated glass slides as support material, on which capture probes were immobilized by a heterobifunctional cross-linker. The comparative results of optimization studies including cross-linker types probe concentrations and hybridization conditions (sequence, temperature and duration) were reported. An optimum hybridization signal was obtained with a 32.5 ? cross-linker, 10???M capture and 20???M signal probe concentrations, respectively. A relatively short hybridization time (2.5?h) provided reproducible array signals. No significant effect of hybridization sequence on the fluorescence intensity was observed. The described platform can specifically detect label-free transgenic sequences with a target of 0.01???M concentration, while the optimized system exhibits great potential for the application of different GMO target sequences (p35S, tNOS, bar and cry) to multiplex array formats.     

Evaluation of surface topography changes in three NiTi file systems using rotary and reciprocal motion: An atomic force microscopy study

Aim: To evaluate the surface topography changes in three nickel‐titanium (NiTi) file systems using either rotary or reciprocal motion using atomic force microscopy (AFM), and to determine the effect of scanning area on the AFM results in this study. Methodology: Five points on a F2 Protaper file, R25 Reciproc file, and a Primary file from WaveOne systems were scanned preoperatively in 1 × 1 and 5 × 5 µm² with an AFM device that can scan an intact (not sectioned) file. One standardized resin block was used for each instrument, according to the manufacturer's recommendations. Points were re‐scanned postoperatively using the same AFM and settings. Root‐mean‐square (RMS) and roughness average (Ra) values were obtained. The preoperative and postoperative surface topographies were compared separately in terms of RMS and Ra values. The surface topography change scores were analyzed using Kruskal–Wallis and Mann–Whitney U tests using a 0.10 significance level. Results: There were no significant differences preoperatively among the NiTi file systems in 1 × 1 or 5 × 5 µm² areas. Postoperatively, the WaveOne Primary had more surface irregularities (significant for 5 × 5 µm² scan in Ra evaluation). Conclusions: Three‐dimensional AFM images of instrument surfaces showed topographic irregularities preoperatively and postoperatively. AFM results differ depending on the scanning area and file used. Microsc. Res. Tech. 77:177–182, 2014. © 2013 Wiley Periodicals, Inc.