INFLUENCE OF GUMS ON DOUGH PROPERTIES AND FLAT BREAD QUALITY OF TWO PERSIAN WHEAT VARIETIES

The effects of separate mixing of two hydrocolloids carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC) at 0.1, 0.3 and 0.5% levels with Sardary and Sorkheh wheat flours (two native Persian varieties) were studied. Chemical and rheological (Farinograph and Extensograph) tests, staling and sensory evaluations were performed on the two flours, their dough and the resulting Lavash flat bread, respectively. On the basis of split‐plot experiment in a complete random design and using the Duncan's multiple range tests, the data were evaluated and the average of replicates was compared at the statistical level of 1% (α = 0.01). Although the CMC and HPMC gums enhanced significantly the dough quality of the two wheat varieties by increasing water absorption and reducing resistances after 90 and 135 min (compared with control), the effect of HPMC was more pronounced than CMC. Anti‐staling properties of HPMC were better than CMC, especially for Sardary flour. Separate addition of 0.5% CMC and HPMC gums to Sorkheh and Sardary flours significantly delayed the staling process of the resulting Lavash bread by more than 45 and 42%, respectively. Additionally, sensory evaluation scores of the Lavash bread made from either Sorkheh flour containing 0.3% CMC or HPMC or Sardary flour containing 0.5% HPMC were 50 and 120% higher than control bread samples, respectively.     

TLC-Digital Image-Based Fluorometric Analysis of Ergosterol and Chitin Content in Food Grains Artificially Infested with <Emphasis Type="Italic">Aspergillus flavus</Emphasis> and <Emphasis Type="Italic">Fusarium verticillioides</Emphasis>

Novel thin-layer chromatography-digital image-based analytical methods were developed for the quantitation of ergosterol and chitin content in six food matrices (rice, wheat, maize, sorghum, groundnut, and sunflower), artificially infested with Aspergillus flavus (MTCC 6513)/Fusarium verticillioides (MRC 826). For ergosterol, single-step method, based on liquid/liquid extraction, was followed by thin-layer chromatography (TLC). Chitin was solubilized using lithium chloride (5%) in dimethyl acetamide and converted to chitosan using 5 N NaOH and subsequently complexed with calcofluor white dye. The absorption and emission maxima of chitosan-calcofluor complex were recorded at λ 350/230 and 430 nm, respectively. The sensitivity based on the limit of detection (LOD) was found to be 100 ng both for ergosterol and chitin analysis. Based on ergosterol and chitin analysis, groundnut and maize were found to be suitable substrates for A. flavus (p?<?0.013 and p?<?0.01), while sorghum followed by groundnut and sunflower were found to be ideal for F. verticillioides (p?<?0.01 and p?<?0.0001) and rice was established as poor substrate as there was no growth on it up to 12 days of incubation. A strong correlation was found between ergosterol and chitin contents with regression (r ²) values of 0.974 and 0.997 in food grains inoculated with A. flavus and F. verticillioides, respectively, during the period of infection. The authenticity of the two methods developed was further confirmed by applying them to commercial food grains and flours. Thus, ergosterol in combination with chitin analysis could be successfully used as an index of fungal contamination employing TLC-digital-based analytical methods.     

Optical, magnetic and structural characterization of Zn1 − x Co x O nanoparticles synthesized by solvothermal method

Nanoparticles of Co-doped ZnO with 3·8, 7·2 and 11·5 wt% were synthesized by solvothermal method through oxalate precursor route. X-ray diffraction studies showed the formation of hexagonal ZnO structure for x?= 0·038, however, secondary phase of Co₃O₄ arises on increasing the Co content up to 11·5%. Transmission electron microscopic studies showed that particles are in the nano-metric regime and the grain size decreases on increasing the Co concentration. Optical reflectance measurements showed an energy bandgap, which decreases on increasing Co concentration. Specific surface area of these nanoparticles was found to be very high and comes out to be 97·6, 112·1 and 603·8 m²g^???1, respectively. All the solid solutions showed paramagnetism with weak antiferromagnetic interactions. It is seen that the antiferromagnetic interaction increases on increasing Co concentration.     

SOLVENT EXTRACTION OF PAKISTAN COALS (III) EXTRACTION AND CHARACTERIZATION OF THE EXTRACTS BY SPECTROSCOPIC TECHNIQUES

Abstract

The Makerwal coal of Pakistan gives higher extractibi1ity with Tetrahydrofuran ( THF ) as compared to Sharigh, Sor-Range and Lakhra coals. The structural characterization of Pakistan coal extracts by FT-IR spectroscopy indicates that all the extracts contained less condensed aromatic rings in comparision to their original coal.     

Novel aromatic and aromatic–aliphatic poly(thiourea‐amide)s for the extraction of toxic heavy metal ions

A series of novel aromatic and aromatic–aliphatic diamines [isophthaloyl bis(3‐(3‐aminophenyl)thiourea), terephthaloyl bis(3‐(3‐aminophenyl)thiourea), adipoyl bis(3‐(3‐aminophenyl)thiourea), sebacoyl bis(3‐(3‐aminophenyl)thiourea)] were synthesized starting from the dinitro compounds. Spectroscopic and elemental analyses were carried out for the structure elucidation of the monomers. Three series of poly(thiourea‐amide)s (PTAMs) bearing C?S groups were prepared through the condensation of new diamines with the diacid chlorides such as isophthaloyl, terephthaloyl and adipoyl chloride. The ensuing PTAMs were characterized using FTIR, ¹H‐NMR and ¹³C‐NMR techniques. Physical properties of the polymers such as solution miscibility, crystallinity, solution viscosity, molecular weight, and thermal properties were measured. Consequently, good organosolubility of these polymers was experiential in amide solvents as DMAc, DMF, DMSO and NMP. Moreover, PTAMs exhibited η_inh in the range of 0.92–1.56 dL/g and GPC measurements revealed M_w around 607 × 10²‐851 × 10². DSC served to envisage the glass transition temperatures (T_g) of poly(thiourea‐amide)s located between 232 and 258°C and the initial decomposition temperatures (T₀) probed by thermogravimetry were in the range of 305–419°C. Structure‐property relationship of these polymers was also studied. Eventually, solid?liquid extraction tests of the selected poly(thiourea‐amide)s systems revealed excellent results because these polymers show nearly 100% elimination of lead and mercury cations from water media. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of individual and combined administration of ochratoxin A and aflatoxin B1 in tissues and eggs of White Leghorn breeder hens

BACKGROUND: Mycotoxins, the secondary fungal metabolites, are unavoidable contaminants of human and animal food and feeds. The objectives of this study were to evaluate the effect of concurrent feeding of ochratoxin A (OTA) and aflatoxin B₁ (AFB₁) to breeder hens, upon their deposition in different tissues and eggs. RESULTS: Residues of OTA and AFB₁ in (ng g^?1) were significantly higher in liver followed by kidneys and breast muscles by 22.54 ± 1.48, 4.22 ± 0.93 and 0.56 ± 0.06 for OTA (group fed OTA at 5 mg kg^?1 diet) and 1.44 ± 0.21, 0.25 ± 0.01 and 0.03 ± 0.01 for AFB₁ (group fed AFB₁ at 5 mg kg^?1 diet), respectively. Residues of OTA and AFB₁ in eggs appeared at days 3 and 5 of toxin feeding and disappeared at days 5 and 6 of withdrawal of mycotoxins contaminated feed, respectively. The residues of OTA and AFB₁ were significantly lower in the tissues of hens fed these toxins concurrently compared with the groups fed OTA and AFB₁ independently. CONCLUSIONS: Residues of OTA and AFB₁ appeared in the tissues and eggs of laying hens kept on OTA‐ and AFB₁‐contaminated diets. Concurrent feeding of OTA and AFB₁ to hens significantly decreased the concentration of OTA and AFB₁ residues in the tissues and eggs. Copyright © 2011 Society of Chemical Industry     

VAPOR-LIQUID EQUILIBRIA OF TOLUENE + n-BUTANOL AND TOLUENE + n-BUTANOL + CALCIUM CHLORIDE AT 94.0kPa

Vapor-liquid equilibrium data of toluene + n-butanol and toluene+ n-butanol + CaCl₂ (at saturation) were measured at a pressure of 94.0 kPa, using a modified Malanowski equilibrium still. The salt investigated in this work, i.e., CaCl₂, exhibits a slight salting-out effect on toluene. The experimental results of the salt-free binary were compared with those obtained from NRTL, ASOG, and UNIFAC models. The latter two models predicted the bubble-point temperatures within 0.5 K (as a root mean square deviation, RMSD) whereas the NRTL model, which was employed to establish thermodynamic consistency by directly fitting the experimental data, correlated the bubble-point temperatures with an RMSD of 0.2 K. On the other hand, the experimental data of toluene+n-butanol+CaCl₂ were compared with those predicted by the NRTL-Tan model for the effect of the electrolyte. This model predicted the bubble-point temperatures with an RMSD of 0.5 K. Calcium chloride has been shown not to have a sensible effect on the azeotropic composition.     

Electrical and optical measurements in the early hydrogen discharge of GLAST-III

This work presents the first electrical and optical measurements of the initial phase of hydrogen discharge in the upgraded spherical tokamak GLAST-III, initiated with electron cyclotron heating (ECH). Diagnostic measurements provide insights into expected and unexpected physics issues related to the initial phase of discharge. A triple Langmuir probe (TLP) has been developed to measure time series of the floating potential, plasma electron temperature and number density over the entire discharge, allowing monitoring of the two phases of the discharge: the ECH pre-ionization phase following by the plasma current formation phase. A TLP has the ability to give time-resolved measurements of the floating potential (V_float), electron temperature (T_e) and ion saturation current (I_sat∝ n_e√kT_e). The evolution of the ECH-assisted pre-ionization and subsequent plasma current phases in one shot are well envisioned by the probe. Intense fluctuations in the plasma current phase advocate for efficient equilibrium and feedback control systems. Moreover, the emergence of some strong impurity lines in the emission spectrum, even after only a few shots, suggests a crucial need for improvements in the base vacuum level. A noticeable change in the shape of the temporal profiles of the floating potential, electron temperature, ion saturation current (I_sat) and light emission has been observed with changing hydrogen fill pressure and vertical magnetic field.     

Microwave-assisted pre-ionization experiments on GLAST-Ⅲ

GLAss Spherical Tokamak(GLAST-Ⅲ) is a spherical tokamak with an insulating vacuum vessel that has a unique single-passage capability for incident microwaves.In this work,electron cyclotron resonance heating(ECRH)-assisted plasma pre-ionization in GLAST-Ⅲ is explored for three radio-frequency(RF) polarizations(the O-,X-,and M-modes) at different toroidal-field(TF) strengths and filled gas pressures.The optimum hydrogen pressure is identified for efficient plasma pre-ionization.A comparison of the plasma pre-ionizations initiated by the O-,X-,and M-modes shows prominent differences in the breakdown time,location,and wave absorption.In the case of O-mode polarization,microwave absorption occurs for a relatively shorter duration,resulting in a bell-shaped electron-temperature(T_e) temporal profile.Microwave absorption is dominant in the case of the X-mode,leading to a broader T_e temporal profile.The M-mode discharge contains features of both the X-and O-modes.Efficient plasma pre-ionization is achieved in the X-mode polarization for the intermediate TF strengths(with a central toroidal magnetic field B_0=0.075 T).Traces of the electron-number density show a similar tendency,as revealed by T_e.These results suggest that the X-mode is the best candidate for efficient plasma pre-ionization at low filled gas pressures(~10~(-2) Pa) in small tokamaks.     

Solution of the 2-dimensional Bratu problem using neural network,swarm intelligence and sequential quadratic programming

In this paper, stochastic techniques have been developed to solve the 2-dimensional Bratu equations with the help of feed-forward artificial neural networks, optimized with particle swarm optimization (PSO) and sequential quadratic programming (SQP) algorithms. A hybrid of the above two algorithms, referred to as the PSO-SQP method is also studied. The original 2-dimensional equations are solved by first transforming them into equivalent one-dimensional boundary value problems (BVPs). These are then modeled using neural networks. The optimization problem for training the weights of the network has been addressed using particle swarm techniques for global search, integrated with an SQP method for rapid local convergence. The methodology is evaluated by applying on three different test cases of BVPs for the Bratu equations. Monte Carlo simulations and extensive analyses are carried out to validate the accuracy, convergence and effectiveness of the schemes. A comparative study of proposed results is made with available exact solution, as well as, reported numerical results.