Effect of an active packaging with citrus extract on lipid oxidation and sensory quality of cooked turkey meat

An antioxidant active packaging was prepared by coating a citrus extract, consisting of a mixture of carboxylic acids and flavanones, on polyethylene terephthalate trays. The effect of the packaging in reducing lipid oxidation in cooked turkey meat and on meat pH, colour characteristics and sensorial parameters was investigated. An untrained sensory panel evaluated the odour, taste, tenderness, juiciness and overall acceptability of the meat, using triangle, paired preference and quantitative response scale tests. A comparison between the antioxidant effects of the different components of the extract was also carried out. The packaging led to a significant reduction in lipid oxidation. After 2 days of refrigerated storage the sensory panel detected differences in odour and, after 4 days, rated the meat stored in the active packaging higher for tenderness and overall acceptability. Citric acid appeared to be the most important component of the extract with regard to its antioxidant potency.     

Optimierung der Anodisierbarkeit bei Aluminiumautomatenlegierungen

Free-cutting aluminium alloys contain beside the typical strengthening alloying elements so called free-cutting phases which give benefits to the machining behaviour of the alloys. Compared to pure aluminium, they have lower melting points and less hardness. The third requirement in this context is their indissolubility in the aluminium matrix. Examples are Bi, Cd, In and Sn. For the commercial anodic treatment, most of the alloying elements are problematic. They could probably generate intermetallic phases in the anodic film, be in charge of building laminate layers, provoke the appearance of blisters, or produce other defects in the protecting layer. Current research about the anodization process at the Institute of Nonferrous Metallurgy, University of Leoben, covers a wide scope of topics, ranging from the machining processes to the final sealing step of anodic treatments and intends to optimize the whole product-chain with attention to sustainable requirements.     

Correlation between hydrogen storage properties and textures induced in magnesium through ECAP and cold rolling

It is feasible to obtain a significant enhancement of the hydrogen storage capability in magnesium by selecting an appropriate sequence of mechanical processing. The Mg metal may be produced with different textures which will then give significant differences in the absorption/desorption kinetics and in the incubation times for hydrogenation. Using processing by equal-channel angular pressing (ECAP), different textures may be produced by changing both the numbers of passes through the ECAP die and the ram speed. Significant grain refinement is easily avoided by using commercial coarse-grained magnesium as the starting material. The use of cold rolling after ECAP further increases the preferential texture for hydrogenation. The results show that the hydriding properties are enhanced with a (002) texture where the improved kinetics lie mainly in the initial stages of hydrogenation. An incubation time is associated with the presence of a (101) texture and this is probably due to the magnesium oxide stability in this direction.     

Trace-metal contamination in proton exchange membrane fuel cells caused by laser-cutting stains on carbon-coated metallic bipolar plates

Trace-metal contamination poses a threat to performance and stability of proton exchange membrane fuel cells (PEMFCs). In this study the source of origin and degree of metal dissolution from carbon-coated 316L bipolar plates (BPPs) are evaluated after a long-term PEMFC test run under conditions resembling a real-life automotive application. Despite intact carbon-coating, metal dissolution occurs from uncoated oxycarbide stains on the plates’ surface. Which correlates with post-mortem detection of chromium, iron and nickel in the membrane electrode assembly. The rate of cell voltage decrease throughout the high current operations is found to be twice as high in the presence of metal ions. Metal dissolution can be correlated with transients in cell voltage during dynamic current load cycling as a result of temporary global fuel starvation. The observed difference in metal dissolution on the anode and cathode BPP indicates weak galvanic coupling between the bipolar plate(s) and the electrode layer(s).     

Corrosion of anode current collectors in molten carbonate fuel cells

Corrosion of metallic parts is one of the life-time limiting factors in the molten carbonate fuel cell. In the reducing environment at the anode side of the cell, the corrosion agent is water. As anode current collector, a widely used material is nickel clad on stainless steel since nickel is stable in anode environment, but a cheaper material is desired to reduce the cost of the fuel cell stack. When using the material as current collector one important factor is a low resistance of the oxide layer formed between the electrode and the current collector in order not to decrease the cell efficiency. In this study, some candidates for anode current collectors have been tested in single cell molten carbonate fuel cells and the resistance of the oxide layer has been measured. Afterwards, the current collector was analysed in scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). The results show that the resistances of the formed oxide layers give a small potential drop compared to that of the cathode current collector.     

Dealcoholized red wine reverse vascular remodeling in an experimental model of metabolic syndrome: role of NAD(P)H oxidase and eNOS activity

The present study examines the effect of chronic administration of dealcoholized red wine Malbec (DRW) on vascular remodeling and NAD(P)H oxidase and endothelial nitric oxide synthase activity (eNOS) in an experimental model of metabolic syndrome induced by fructose administration. Thirty-day old male Wistar rats were fed a normal rat diet (control) or the same diet plus 10% fructose in drinking water (FFR). During the last 4 weeks of a 10-week period of the corresponding diet, a subgroup of control and FFR (n=8 each) received DRW in their drinking water. Systolic blood pressure (SBP), a homeostasis model assessment of insulin resistance (HOMA-IR), aortic NAD(P)H oxidase and eNOS activity in the heart and vascular tissue were evaluated. Vascular remodeling was evaluated in the left carotid artery (CA) and interlobar, arcuate and interlobular renal arteries (RA) through lumen to media (L/M) ratio determination. At the end of the study FFR increased the SBP (p < 0.001), HOMA-IR (p < 0.001), and aortic NAD(P)H oxidase activity (p < 0,05) but reduced cardiac and vascular eNOS activity (p < 0.01), L/M ratio in CA (p < 0.001) and RA (p < 0.01) compared with the C group. DRW reduced SBP (p < 0.05), aortic NAD(P)H oxidase (p < 0.05), and recovered eNOS activity (p < 0.001) and L/M in CA (p < 0.001) and RA (p < 0.001) compared with FFR. This study provides new data about the beneficial effect of DRW on oxidative stress and vascular remodeling in the experimental model of metabolic syndrome. Data suggest the participation of mechanisms involving oxidative stress in FFR alterations and the usefulness of natural antioxidant substances present in red wine in the reversion of these changes.     

Effect of cold rolling on the structure and hydrogen properties of AZ91 and AM60D magnesium alloys processed by ECAP

This investigation was conducted to evaluate the effect of cold rolling on the structure and hydrogen properties of two magnesium alloys, AZ91 and AM60D, after processing by equal-channel angular pressing (ECAP). The results show that the use of cold rolling after ECAP significantly increases the preferential texture for hydrogenation and increases the potential for the use of these alloys as hydrogen storage materials. The ECAP was performed through two different numbers of passes in order to give different grain sizes and both materials were subsequently cold-rolled through the same numbers of passes for a comparison of the hydrogenation absorption. It is shown that the hydriding properties are enhanced by an (0001) texture which improves the kinetics primarily in the initial stages of hydrogenation. The results demonstrate that optimum sorption properties may be acquired through a combination of fine grains and appropriate texture.     

Method for retrospective collection of work-related psychosocial risk factors for musculoskeletal disorders: Reliability and aggregation.

Information on psychosocial work conditions during a 24-year period for 484 participants was collected retrospectively. Analyses were made of the interrater reliability, stability, specificity, and aggregation of data. The main finding was that it is possible to collect reliable information about psychosocial work conditions retrospectively for a long period of years when using a time ruler in a structured interview when earlier conditions are compared with the present. Interrater agreement was satisfactory for the larger part of the studied retrospective psychosocial risk factors and excellent for some of them. For most of the studied risk factors, the risk of overreporting exposure was low. The aggregation of data resulted in 2 indexes: poor social relations at work and low influence over work conditions. In conclusion, an individual time ruler works satisfactorily as a method of collecting retrospective information about psychosocial risk factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)