Biobased packaging for improving preservation of fresh common mushrooms (Agaricus bisporus L.)

Freshness of common mushrooms was related to the internal atmosphere composition during modified atmosphere packaging (MAP) experiments at 20 °C and 80% RH with stretchable polyvinylchloride (PVC) film, paper, and the same paper coated with a wheat gluten solution. MAP with the stretchable film led to a detrimental deterioration of mushrooms after only one day of storage: dark brown blotches appeared and almost 30% of mushrooms exhibited open veil. This was due to the formation of condensed water at the inner surface of the material and onto mushrooms combined to a high O₂ partial pressure (16 kPa) in the headspace. Wheat gluten (WG) coated paper was the most effective to improve the shelf-life of mushrooms since it allowed the preservation of a fair colour, unbroken veils, and an acceptable texture during 3 days. This beneficial effect was attributed to the combination of a medium CO₂ (9.5 kPa) and low O₂ (2.5 kPa) partial pressure, without condensation. The main drawback of using WG-coated paper was its high water vapour permeability that led to an important weight loss (3.8 wt.% on day 3). However it did not affect the overall quality of mushrooms within the storage duration.

Industrial relevance

Even with the development of micro-perforated materials that provide the largest range of O₂ and CO₂ permeability values, several limitations are still encountered for synthetic MAP applications such as

– an insufficient perm-selectivity ratio that remains lower than 6 (value of 1 for micro-perforated material): generated atmosphere cannot reach both low O₂ and low CO₂ partial pressures and then are not adapted to CO₂-sensitive fresh produces.

– unattractive water condensation at the inner surface of the packaging that might occur due to a low water vapour permeability, favouring the development of microorganisms.

– their non biodegradability.

Previous studies reported a high selectivity ratio and a high water vapour permeability for biodegradable materials made from crops proteins (wheat gluten, for instance) that appeared well adapted for fresh fruits and vegetables preservation. However, despite low cost and such interesting functional properties, these materials exhibited poor mechanical properties and cannot be used as packaging material. Combination with other materials, such as cellulosic fibres, appeared to one way to get round this major drawback without losing its biodegradability. Indeed paper exhibits an environmental-friendliness potential (recyclability, sustainability, biodegradability, and compostability) and a high versatility in food packaging.By choosing common mushrooms, known to be sensitive to high CO₂ content, and a stretchable PVC film, commonly used to over-wrap mushrooms in tray (on European market), we demonstrate that this material was greatly less effective than a new biobased material (wheat gluten film coated onto paper) developed in collaboration with Smurfit Worldwide Research Center. This work confirms the interest in developing functionalised paper based packaging material with agro-based polymers adapted to the storage of fresh fruits and vegetable storage in ambient temperature.     

A new dual luminescent pillared cerium(IV)sulfate–diphosphonate

A new pillared cerium(IV) sulfate–diphosphonate with formula Ce₂(2H₂O)[(O₃PCH₂)–NC₁₀H₁₈N–(CH₂PO₃)(SO₄)₂] · 6H₂O has been hydrothermally synthesized and its structure has been solved ab initio from laboratory X-ray powder diffraction data.The luminescent and thermal properties of this compound have been preliminarily studied and the encouraging results place it in the field of functional hybrid materials.     

Comparison of low‐temperature processes for oil and coenzyme Q10 extraction from mackerel and herring

Among the fat fish species available from Eastern Quebec (Canada), whole Atlantic mackerel (Scomber scombrus) and herring (Clupea harengus) represent abundant fishery resources which are currently under‐utilized. They have relatively high contents of oil and coenzyme Q10 (CoQ10) in their tissues, which could be valuable for nutraceutical applications. Therefore, two low‐temperature extraction processes were compared for the recovery of oil and CoQ10 from these resources, such as enzymatic hydrolysis using Protamex? and supercritical CO₂ (SCO₂) using fish lyophilizates. The results revealed that highest yields of oil and CoQ10 were obtained using the enzymatic hydrolysis process with mackerel. Whatever the process used, CoQ10 concentrations were higher in herring oil, due mainly to a more selective extraction of CoQ10 over that of the oil. The highest CoQ10 recovery rates (extraction efficiencies) were obtained using the enzymatic hydrolysis process with both types of fish, but also the SCO₂ process with herring under some conditions. For mackerel, the lower CoQ10 recovery rates obtained from the SCO₂ process were explained by its more important matrix effect. An economic assessment of both processes revealed that the enzymatic hydrolysis extraction process would be the most promising for up‐scaling the recovery of oil and CoQ10 from these resources.     

Anthropogenic impacts in North Poland over the last 1300 years — A record of Pb, Zn, Cu, Ni and S in an ombrotrophic peat bog

Lead pollution history over Northern Poland was reconstructed for the last ca. 1300 years using the elemental and Pb isotope geochemistry of a dated Polish peat bog. The data show that Polish Pb-Zn ores and coal were the main sources of Pb, other heavy metals and S over Northern Poland up until the industrial revolution. After review of the potential mobility of each element, most of the historical interpretation was based on Pb and Pb isotopes, the other chemical elements (Zn, Cu, Ni, S) being considered secondary indicators of pollution. During the last century, leaded gasoline also contributed to anthropogenic Pb pollution over Poland. Coal and Pb-Zn ores, however, remained important sources of pollution in Eastern European countries during the last 50 years, as demonstrated by a high ²⁰⁶Pb/²⁰⁷Pb ratio (1.153) relative to that of Western Europe (ca. 1.10). The Pb data for the last century were also in good agreement with modelled Pb inventories over Poland and the Baltic region.     

Anti-Inflammatory Effect of Very High Dose Local Vessel Wall Statin Administration: Poly(L,L-Lactide) Biodegradable Microspheres with Simvastatin for Drug Delivery System (DDS)

Atherosclerosis involves an ongoing inflammatory response of the vascular endothelium and vessel wall of the aorta and vein. The pleiotropic effects of statins have been well described in many in vitro and in vivo studies, but these effects are difficult to achieve in clinical practice due to the low bioavailability of statins and their first-pass metabolism in the liver. The aim of this study was to test a vessel wall local drug delivery system (DDS) using PLA microstructures loaded with simvastatin. Wistar rats were fed high cholesterol chow as a model. The rat vessels were chemically injured by repeated injections of perivascular paclitaxel and 5-fluorouracil. The vessels were then cultured and treated by the injection of several concentrations of poly(L,L-lactide) microparticles loaded with the high local HMG-CoA inhibitor simvastatin (0.58 mg/kg) concentration (SVPLA). Histopathological examinations of the harvested vessels and vital organs after 24 h, 7 days and 4 weeks were performed. Microcirculation in mice as an additional test was performed to demonstrate the safety of this approach. A single dose of SVPLA microspheres with an average diameter of 6.4 μm and a drug concentration equal to 8.1% of particles limited the inflammatory reaction of the endothelium and vessel wall and had no influence on microcirculation in vivo or in vitro. A potent pleiotropic (anti-inflammatory) effect of simvastatin after local SVPLA administration was observed. Moreover, significant concentrations of free simvastatin were observed in the vessel wall (compared to the maximum serum level). In addition, it appeared that simvastatin, once locally administered as SVPLA particles, exerted potent pleiotropic effects on chemically injured vessels and presented anti-inflammatory action. Presumably, this effect was due to the high local concentrations of simvastatin. No local or systemic side effects were observed. This approach could be useful for local simvastatin DDSs when high, local drug concentrations are difficult to obtain, or systemic side effects are present.     

Millimeter wave band ultra wideband transmitter MMIC

This paper presents a new millimeter-wave (MMW) ultra wideband (UWB) transmitter MMIC which has been developed in an OMMIC 0.1 μm GaAs PHEMT foundry process (f_t = 100 GHz) for 22-29 GHz vehicular radar systems. The transmitter is composed of an MMW negative resistance oscillator (NRO), a power amplifier (PA), and two UWB pulse generators (PGs). In order to convert the UWB pulse signal to MMW frequency and reduce the total power consumption, the MMW NRO is driven by one of the UWB pulse generators and the power amplifier is triggered by another UWB pulse generator. The main advantages of this transmitter are: new design, simple architecture, high-precision distance measurements, infinite ON/OFF switch ratio, and low power consumption. The total power consumption of the transmitter MMIC is 218 mW with a peak output power of 5.5 dBm at 27 GHz.     

Viewpoint on the Formation and Evolution of Annealing Twins During Thermomechanical Processing of FCC Metals and Alloys

Metallurgical and Materials Transactions A - The question of the formation mechanism of annealing twins in face-centered cubic metals and alloys, which is still not resolved in spite of the fact...     

A new inhomogeneous partially reflecting surface for Fabry‐Perot antenna to reduce side lobe level

In this article, an extension of the spatial filter method to study Fabry‐Perot antennas with homogeneous or inhomogeneous partially reflecting surface (PRS) of finite size is proposed. This tool was subsequently validated through the study of different Fabry‐Perot antennas, with homogeneous PRS and inhomogeneous GRadient‐INdex (GRIN) PRS that present very high side lobe level (SLL). Since they are due to structure truncation, a new inhomogeneous PRS to reduce the SLL is designed with the new analytical tool. The new inhomogeneous PRS for Fabry‐Perot antenna is characterized by simulations and measurements. Compared to the homogeneous PRS antenna, the proposed PRS allows a SLL reduction of 5 dB without decreasing the 14 dBi directivity.