Functional properties of microwave-treated wheat gluten

In this study, the effects of microwave treatments on solubility, foaming and emulsifying properties of gluten were investigated. The solubility of microwave-heated gluten proteins gradually decreased as the treatment time increased, at all power levels applied. The highest solubility values were obtained for gluten samples microwave treated at 50% power level. The lowest emulsifying capacity values were obtained with the samples heated at 100% power level at all treatment times. The emulsifying stability values of microwave-heated gluten samples were found to be slightly higher than those of the control sample. However, there were no significant differences among the microwave power levels at all treatment times in terms of the emulsifying stability values. The foam volumes of the samples treated at 80 and 100% energy levels were slightly higher than those of the control gluten. The foam stability values of microwave-heated gluten samples gradually increased with treatment time at all power levels, which were more pronounced at 100% power level. Generally, microwave treatment did not cause major changes on the protein electrophoretic patterns of gluten samples at the power levels used.     

Synthesis of conducting polysiloxane — polypyrrole graft copolymers

Summary Polysiloxane-polypyrrole graft copolymers have been synthesized by a series of chemical reactions and subsequent electropolymerization. First, the hydrosilation of 4-vinyl aniline by dimethyl-methylhydrosiloxane copolymer gave the corresponding aminophenyl functional polydimethylsiloxane (PDMS-NH₂). The side chain pyrrole functionalized polysiloxanes were then prepared by the reaction of PDMS-NH₂ with glycidylpyrrole. Finally, the synthesis of graft copolymers of polysiloxane and pyrrole has been achieved electrochemically by using two different electrolytes, p-toluene sulfonic acid (PTSA) and tetrabutylammonium tetrafluoroborate (TBAFB). Characterization of these graft copolymers were performed by a combination of techniques consisting of scanning electron microscopy (SEM), thermal gravimetry (TGA), differential scanning calorimetry (DSC) analyses and FT-IR studies. The conductivities were measured by four-probe technique. Received: 19 September 2001/ Revised version: 4 December 2001/ Accepted: 2 December 2001     

Kinetics and mechanism of methylene blue removal by electrosynthesized ferrate(VI)

The oxidation of methylene blue (MB) by electrosynthesized ferrate(VI) in a semi-batch reactor is investigated. The effects of pH, Fe(VI) dose and initial MB concentration on the efficiency of the degradation process were studied. The original pH of MB solution was found more effective on the degradation and colour removal as 96.82% MB removal and 40.36% colour removal were gained. Initial MB solution and Fe(VI) dose affected the removal efficiencies. Degradation of MB by Fe(VI) was the second-order reaction kinetics. The density functional theory (DFT) analysis confirmed that density is intended mostly on the phenyl rings and least of all on the bonding orbitals of the middle heterocycle of МВ.     

Effects of probiotic bacteria and oils on fatty acid profiles of cultured cream

The aim of this study was to determine the effects of using various probiotic bacteria and plant oils in cultured cream on the fatty acid profiles including conjugated linoleic acids (CLA). L. acidophilus, B. bifidum, S. thermophilus and L. bulgaricus, P. thoenii (jensenii) P126, and P. jensenii B1264 and a mixed culture (blend of L. acidophilus, B. bifidum, S. thermophilus and L. bulgaricus) were used in the fermentation of cream samples at a level of 2%. Cream samples were fortified with sunflower oil, soybean oil and hazelnut oil at a level of 2%. Microbial counts and fatty acid profile analysis were performed. The microbial results demonstrated that fermented cream could be a superior product for the presence of probiotics. Even though the cream samples contained 52% milk fat, in the majority of the samples growth of probiotic bacteria was higher than 10⁶ cfu/g. Concentrations of short‐chain fatty acids such as butyric, caproic and capric acids in cultured cream samples differed depending on the cultures used, while long‐chain unsaturated fatty acids were significantly affected by the plant oil fortification. The highest CLA content was obtained in the sample produced with B. bifidum, containing 0.73 mg of CLA/g fat. The effect of different plant oils on CLA concentration was significant (p >0.05) for HO + YC, SFO + LBYC and SO + LBYC. Results of the study are important for the dairy industry since it is the first publication on fermented cream with improved functional properties. The development of functional cultured cream with plant oils and probiotic bacteria would provide an important alternative dairy product.     

Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation

This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge.     

Single Multiplicative Neuron Model Artificial Neural Network with Autoregressive Coefficient for Time Series Modelling

Neural Processing Letters - Single multiplicative neuron model and multilayer perceptron have been commonly used for time series prediction problem. Having a simple structure and features of easily...     

Synthesis of tin oxide-coated gold nanostars and evaluation of their surface-enhanced Raman scattering activities

Tin oxide-coated gold nanostar hybrid nanostructures are prepared by first synthesizing gold nanostars (ca. 400 nm), then introducing Na₂SnO₃ precursor followed by its hydrolysis and formation of a tin oxide layer on nanoparticle surface. The synthesized hybrid structures have been characterized by combination of UV–Vis spectroscopy, transmission electron microscope (TEM), energy-dispersive X-ray studies, scanning electron microscope (SEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The TEM and SEM analyses showed that gold nanostars have a coating with an approximate thickness of 15 nm. The tin (IV) oxide coating on the gold nanostars was identified by XRD and XPS analyses and confirmed by FTIR spectroscopy. Surface-enhanced Raman scattering (SERS) spectroscopy was performed on tin oxide-coated and uncoated gold nanostars with crystal violet as a probe molecule. The SERS studies revealed field enhancement properties of Au nanostars, thus their strong SERS activity remained after tin oxide coating.     

Investigation of physicochemical properties of breads baked in microwave and infrared-microwave combination ovens during storage

Staling of breads baked in different ovens (microwave, infrared-microwave combination and conventional) was investigated with the help of mechanical (compression measurements), physicochemical (DSC, X-ray, FTIR) and rheological (RVA) methods. The effect of xanthan-guar gum blend addition on bread staling was also studied. Xanthan-guar gum blend at 0.5% concentration was used in bread formulation. The gums were mixed at equal concentrations to obtain the blend. After baking, the staling parameters of breads were monitored over 5 days storage. During storage, it was seen that hardness, retrogradation enthalpies, setback viscosity, crystallinity values, and FTIR outputs related to starch retrogradation of bread samples increased, whereas FTIR outputs related to moisture content of samples decreased significantly with time. The hardness, retrogradation enthalpy, setback viscosity, and crystallinity values of microwave-baked samples were found to be highest among other heating modes. Using IR-microwave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones in terms of retrogradation enthalpy and FTIR outputs related to starch retrogradation. Addition of xanthan-guar gum blend decreased hardness, retrogradation enthalpy and total mass crystallinity values of bread samples showing that staling was delayed.