Interactions between flavour release and rheological properties in model custard desserts: Effect of starch concentration and milk fat

The influence of the concentration of various reagents and of the storage time on the flavour release of custard desserts was evaluated by headspace solid-phase microextraction and supported by rheological measurements. The presence of milk fat induced a significant decrease of the headspace concentration of flavour compounds, mainly due to hydrophobic matrix–flavour interactions. An elevated starch concentration enhanced the strength of the custard gels considerably. However, the increasing starch concentration resulted in an increased flavour release at low flavour concentrations, while a tendency to flavour retention was noted at higher flavour concentrations. During storage time, a denser network was formed as shown by rheological measurements, but no significant difference in flavour release was noted upon storage (three days). These results show that the complex interactions between flavour compounds and the food matrix in a model custard are difficult to predict and have to be carefully evaluated by a combination of rheological parameters and physicochemical interactions.     

High resolution two-dimensional electrophoresis as a tool to differentiate wild from farmed cod (Gadus morhua) and to assess the protein composition of klipfish

Tris and CHAPS–urea extracts from wild and farmed cod muscle and from rehydrated cod klipfish fillets were analyzed by one (1DE) and two-dimensional electrophoresis (2DE). 2DE maps of tris extracts from farmed cod differed from the wild in a series of spots of Mw 35 and 45 kDa. The CHAPS–urea extracts from farmed cod had a several spots of Mw between 100 and 45 kDa, which were hardly detectable in wild cod and very prominent in klipfish. Klipfish was clearly different from the other samples: the myosin heavy chain was hardly detectable in these samples, and the tris extracts contained fewer, and the CHAPS–urea more spots than the corresponding extracts from the raw muscles. Further identification of these potentially diagnostic spots will make it easier the differentiation of farmed from wild cod and the evaluation of klipfish processing on the protein content of the product.     

A multiple criteria evaluation of multi-family apartment block's maintenance contractors: I—Model for maintenance contractor evaluation and the determination of its selection criteria

The paper presents a model that describes the process of selecting dwelling maintenance contractors. The model is based on a multi-criteria evaluation of maintenance contractors, the determination of their utility level for the building's users and a bid price in negotiations that are made according to the results of the multiple criteria analysis. The proposed model could further be applied to plan dwelling maintenance operations. The criteria of maintenance contractor evaluation are selected by taking into consideration the interests and goals of the building's users as well as factors that influence the process of maintenance's efficiency. The correlation of the criteria characterizing maintenance contractors from various perspectives was determined.     

Evaluation of corrosion defects in oil pipelines based on the approaches of fracture mechanics

We study the development of corrosion defects in an industrial oil pipeline. Defects appearing in the pipeline after 5 and 10 yr of operation are measured by the ultrasonic method. It is shown that, after 10 yr of operation, the pipe wall becomes thinner by 22% (as compared with its initial thickness). To evaluate the defectiveness of state of the pipeline, we use the concepts of J -integral and crack-opening displacement δ. The experimental data on corrosion defects are used to find the values of J-integral.     

Codeposition of copper and tin from acid sulphate solutions containing polyether sintanol DS-10 and benzaldehyde

Cu(II) and Sn(II) reduction in acid sulphate solutions containing polyether laprol DS-10 and benzaldehyde (BA) was studied by means of impedance, voltammetric, XPS and XRD techniques. Both additives demonstrate weak surface activity on copper substrate in Cu(II) solutions in the absence of halide impurities. In contrast, their effect is overwhelmingly higher in the Sn|Sn(II) system. The additives induce a significant increase in Sn-electrode impedance and simultaneous strong inhibition of Sn(II) reduction over a wide range of cathodic polarizations. The effects of sintanol and BA in mixed Cu(II) and Sn(II) solutions demonstrate a kind of synergism. Underpotential deposition of tin on foreign (copper) substrate is observed at potentials more positive than the equilibrium potential of the Sn|Sn²⁺ system. Incorporation of tin into the Cu crystalline lattice results in the formation of multiphase material containing pure copper, α-CuSn phase, and intermediate hexagonal hcp phase. Formation of the pure tin phase occurs at more negative potentials and results in a strong inhibitive adsorption that manifests itself in the development of a deep voltammetric minimum. The tin content in the coatings depends on BA concentration and, particularly, on the electrode potential.     

Production of synthesis gas from propane using thermal water vapor plasma

In this work, an experimental plasma-chemical reactor equipped with a water vapor plasma torch was used for catalyst-free thermal plasma reforming of propane to produce a synthesis gas. Thermal arc discharge plasma (a mixture of water vapor and argon) was generated at atmospheric pressure.     

Electroless cobalt deposition from a glycinate solution using morpholine borane as a reducing agent

Electroless cobalt films were deposited from a neutral pH glycinate solution without additives using morpholine borane (MB) as a reducing agent. The rate of deposition rises with increase in concentration of solution components (Co ions, MB and glycine), and pH. The efficiency of cobalt discharge increases when the deposition is performed from the Co(II) complex with glycine. XPS data indicate that boron and oxygen are incorporated into the cobalt films. Two forms of boron (elemental and its oxide) were detected in the electrolessly deposited cobalt films.     

Comparison Study of Gravity-Dependent Displacement of Amyloplasts in Statocytes of Cress Roots and Hypocotyls

In this study, the kinetics of gravity-dependent movement of amyloplasts (statoliths) along root statocytes and hypocotyls (endodermis cells) has been analyzed and compared in order to testify cytoskeleton involvement in the displacement of statoliths in cress (Lepidium sativum L.) seedling statocytes. After 32 h of growth at 1 g or under a fast clinorotation (50 rpm), the seedlings were treated for 24 min as follows: exposition to clinorotation or 180° inversion and the action of gravitational force in root tip or hypocotyl tip direction. Statolith displacement was studied by light microscopy on semi-thin longitudinal sections of hypocotyls and root caps, measuring the distance between the centre of plastids and morphological cell bottom. Considerable temporal differences have been determined between the kinetics of the longitudinal motion of amyloplasts in root and hypocotyl statocytes of 1-g seedlings upon exposition to fast clinorotation and inversion. In statocytes of both organs of seedlings grown under fast clinorotation, the gravity provoked displacement of statoliths in the direction of its action; however, the displacement was much faster in hypocotyl than in root statocytes. It has been assumed that the gravity-determined longitudinal transport of amyloplasts, both in hypocotyl endodermic cells and root statocytes of cress seedlings, is modulated by the cytoskeleton.     

Formation of Phosphate Coatings on Steel and Corrosion Performance of Phosphated Specimens in Alkaline Solutions

Crystalline and amorphous phosphate coatings were formed on steel samples with the intention of using them for corrosion resistance enhancement of steel reinforcement in concrete. The physical properties of the phosphate coatings were studied using the following methods: the weights of phosphate coating and those of dissolved metal were calculated from gravimetric measurements, surface morphology studies were carried out with an AFM and the phase composition of coatings was analysed by X-ray diffraction. An indicator of film porosity was considered as the maximum difference between potential values of growth completeness of phosphate film and those of metal dissolution. The corrosion behaviour of phosphated steel specimens was studied in 1 × 10^?5 and 0.1 M NaOH solutions (pH=8.5, 13) without/with 0.1 M Cl^? ions. The phosphate coating protection abilities were related to its composition, thickness and porosity. All the crystalline phosphate coatings studied protect steel from corrosion in alkaline solutions in a wide range of pH even when Cl^? ions are present. The best protective properties were exhibited by medium weight crystalline phosphate coatings. Amorphous phosphate coating is not chemically stable in strongly alkaline solutions because of the hydrolysis of iron phosphate present in it.     

Influence of Corrosion on Microstructure of Chromated Zinc Surfaces. Part 1. Microstructure changes of electrodeposited zinc in the process of chromating

The microstructure of zinc surfaces has been investigated using x-ray photoeiectron spectroscopy and scanning electron microscopy. The inclusion of a 0.5% HNO₃ bright dip stage into the technological process of zinc chromating stimulates equal-rate generation of anode-active spots on zinc surfaces and at the same time influences the formation of more uniform conversion coating. Intensive zinc surface etching is observed under the forming conversion coating.