Volatile composition and nutritional quality of the edible mushroom Polyporus tenuiculus grown on different agro‐industrial waste

The volatile composition and the nutritional value of Polyporus tenuiculus grown on supplemented and nonsupplemented wheat straw and willow sawdust were determined. Thirty‐nine volatile compounds were detected, including acids, esters, alcohols, hydrocarbons, aldehydes and ketones. The main volatile compound in all samples was 1‐octen‐3‐ol, with increasing levels in mushrooms cropped on supplemented substrate. In addition, several precursors of this alcohol were identified in lower percentages. Mushrooms grown on supplemented substrates showed lower fat (5.2–5.7%) and carbohydrate contents (48.2%) and higher protein content (22–22.5%). Fibre and ash contents showed some variations between types of substrates. Compared to other edible fungi, P. tenuiculus high fibre and protein contents point to this species as a healthy nutritional alternative of interest for the food industry. Moreover, the wide spectrum of volatile compounds of P. tenuiculus reveals great potential for biotechnological applications such as the production of “non artificial” mushroom flavour.     

APPLICATION OF THE PIECEWISE PARABOLIC FINITE ANALYTIC METHOD TO THE THREE-DIMENSIONAL CAVITY FLOW

Abstract

The three-dimensional piecewise parabolic finite analytic method (PPFAM3D), with vector potential and vorticity as dependent variables, was used to solve the steady three-dimensional (3-D) laminar cavity flow. Predictions were obtained for Reynolds numbers between 100 and 2000. Results for Re = 100, 400, and 1000 are compared with those available in the literature. The overall agreement is excellent. Results are also compared with the two-dimensional PPFAM cavity flow, showing the effect of three-dimensionality on the velocity predictions at the symmetry plane. The PPFAM3D is a robust numerical algorithm requiring no relaxation to produce physically meaningful and numerically converged solutions. It is a promising tool for solving a variety of flow phenomena governed by unsteady second-order partial differential convection-diffusion equations     

Lactobacillus rhamnosus CRL1505 enhances systemic and respiratory innate immune response in immunocompromised malnourished mice

The effect of Lactobacillus rhamnosus CRL1505 on blood and bone marrow (BM) myeloid cells and their correlation with resistance against Streptococcus pneumoniae infection was evaluated in protein-malnourished mice. Repletion of malnourished mice with supplemental L. rhamnosus improved recovery of BM responsiveness against the infectious challenge through increase in myeloid progenitors and mobilisation of granulocytes. The CRL1505 strain normalised the number of Gr1⁺ cells and Gr1^low/Gr1^high cells balance in BM. These changes in BM correlated with improved neutrophils recruitment, higher phagocytic activity and increased resistance against pneumococcal infection in probiotic-treated mice. This research provides strong evidence of the importance of dietary supplementation with probiotic bacteria to reverse alterations in myeloid progenitors in malnourished mice. The present results strongly suggest that the CRL1505 strain could be used in the development of probiotic foods, which would be especially useful for the recovery of immunocompromised hosts.     

Ultra flat ideal concentrators of high concentration

A new method for the design of nonimaging devices is presented. Its application to the design of ultra flat compact concentrators is analyzed. These new concentrators are based on a combination of two stages: the first one is composed of a large number of small structures placed side by side and the second one is a very compact single device concentrating the radiation to the limit. These devices are ideal for 2D. These compact designs are much more compact than the traditional ones like lens–mirror combinations or parabolic primaries with nonimaging secondaries. Besides, they can be designed for any acceptance angle, while the traditional ones are limited to small acceptance angles.     

PECVD deposition of device-quality intrinsic amorphous silicon at high growth rate

The combined influence of RF-power density (RFP) and silane flow-rate (Φ) on the deposition rate of plasma-enhanced chemical vapour deposition (PECVD) intrinsic amorphous silicon has been investigated. The correlation of the results obtained from the characterisation of the material with the silane deposition efficiency, as deduced from mass spectrometry, has led to an interpretation allowing to deposit intrinsic amorphous-silicon films having an optical gap of 1.87 eV and a photoconductive ratio (ratio of ambient-temperature conductivities under 1 sun AM1 and in dark) of 6 orders of magnitude at growth rates up to 10 Å/s, without any structural modification of the PECVD system used. Such results are considered of high relevance regarding industrial competitiveness.     

Fuel-cell energy generation system based on the series-capacitor boost converter

This work introduces the development of a power-electronics customizable energy system for their application on renewable energy generation based on proton-exchange membrane fuel cells. The customizable energy system aims to regulate the output voltage from a fuel cell, which has a relatively low amplitude and wide range of variation, to a fixed voltage to feed a grid-tie inverter. The customizable energy system proposed is based on a dc-dc converter for which different configurations (topologies) are available, such as the traditional single-phase boost or the (interleaved) multi-phase boost. The dc-dc converter of the energy system is based on the series-capacitor boost converter, a recently proposed converter that has a similar configuration to the interleaved boost converter. This article shows that the series-capacitor boost topology offers benefits in the proposed application. An experimental prototype was developed and tested in order to demonstrate the advantages of the system proposed.     

Modified paramagnetic beads in a microfluidic system for the determination of zearalenone in feedstuffs samples

In this work, we have developed and characterised a novel microfluidic immunoassay methodology for rapid and sensitive quantification of ZEA in feedstuffs samples. The detection of ZEA was carried out using a competitive direct immunoassay method based on the use of anti-ZEA monoclonal antibodies immobilized on magnetic microspheres 3-aminopropyl-modified manipulated for an external remobilize magnets. The ZEA in feedstuffs sample is allowed to compete with ZEA-horseradish peroxidase (HPR) conjugated for the immobilized anti-ZEA antibody. The HPR, in the presence of hydrogen peroxide (H₂O₂) catalyses the oxidation of 4-tert-butylcatechol (4-TBC) whose back electrochemical reduction was detected on gold electrode at 0.0 V. The calculated detection limits for electrochemical detection and ELISA procedure were 0.41 and 2.56 μg kg⁻¹ respectively, the intra and inter-assay coefficients of variation were below 6.5% and the total assay time was 30 min. The microfluidic immunosensor showed higher sensitivity and lower detection limits than the standard ELISA method, which shows potential for detecting ZEA in foods and feeds diagnosis.     

Performance model to assist solar thermal power plant siting in northern Chile based on backup fuel consumption

In response to environmental awareness, Chile introduced sustainability goals in its electricity law. Power producers must deliver 5% from renewable sources by 2010 and 10% by 2024. The Chilean desert has a large available surface with one of the highest radiation levels and clearest skies in the World. These factors imply that solar power is an option for this task. However, a commercial plant requires a fossil fuel system to backup the sunlight intermittency. The authors developed a thermodynamical model to estimate the backup fraction needed in a 100 MW hybrid -solar-fossil- parabolic trough power plant. This paper presents the model aiming to predicting the performance and exploring its usefulness in assisting site selection among four locations. Since solar radiation data are only available in a monthly average, we introduced two approaches to feed the model. One data set provided an average month with identical days throughout and the other one considered an artificial month of different daylight profiles on an hourly basis for the same monthly average. We recommend a best plant location based on minimum fossil fuel backup, contributing to optimal siting from the energy perspective. Utilities will refine their policy goals more closely when a precise solar energy data set becomes available.     

Optimisation of Dosidicus gigas mantle proteolysis at industrial scale

The use of enzymatic preparations in food processing is very old and has a number of advantages such as the high specificity of the enzymes, which avoids unwanted products, and their use at moderate temperatures, hence reducing alterations in the most labile components of food. The aim of this work is to supply information that would allow the use of Dosidicus gigas, as a source of raw material, in the preparation of diverse frozen products. With this purpose, we studied the effect of seven proteases: collagenase F, collagenase H, collagenase/dispase, papain, pronase, subtilisin and trypsin, and centered on the rheological and sensory evaluation of the changes which occurred in the texture of D. gigas, in order to establish the optimal conditions for the use of each enzyme.