93 research outputs found
Use of edible and biodegradable coatings in fresh cut pineapple.
The use of edible coatings in vegetable products has been increasing because it offers several advantages as being biodegradable and extends the shelf-life of fruits and vegetables. The objective of this work was to evaluate the effect of two biodegradable edible coatings, sodiumalginate and Chitosan, on the quality and shelf life of minimally processed pineapple storage at 10°C. Five L of each coating solutions were prepared as following - 2% alginate solution: 100 g of Algenic acid sodium salt in 5 L of distilled water, heated at 70°C under constant stirring - 0,75% Chitosan solution: 150 g of monohydrated citric acid dispersed in 5 L of distilled water and addition 37.5g of Chitosan (Crab shells Chitosan, minimum 85% deacetylated, SIGMA), heated to 60°C to dissolve the Chitosan. The coating solutions were then stored at 5°C before the dipping. The Chitosan coating had an important benefic effect on the microbiological contamination and on the maintenance of the total phenolic content. The high concentration of citric acid in the coating solution contributed to the antimicrobial effect but changed the sensory taste of fresh pineapple. The alginate coating also decreased the contamination of yeasts and molds but its effect was lower than the Chitosan one. Visual aspect of its coating solution can be not well accepted by the consumers. The concentration of alginate must be decreased to avoid the formation of a too thick gel. The Chitosan treatment resulted in the best product at the end of experiment and the most slight decreasing of phenolic compounds during all the experiments
Melting of hybrid organic-inorganic perovskites.
Several organic-inorganic hybrid materials from the metal-organic framework (MOF) family have been shown to form stable liquids at high temperatures. Quenching then results in the formation of melt-quenched MOF glasses that retain the three-dimensional coordination bonding of the crystalline phase. These hybrid glasses have intriguing properties and could find practical applications, yet the melt-quench phenomenon has so far remained limited to a few MOF structures. Here we turn to hybrid organic-inorganic perovskites-which occupy a prominent position within materials chemistry owing to their functional properties such as ion transport, photoconductivity, ferroelectricity and multiferroicity-and show that a series of dicyanamide-based hybrid organic-inorganic perovskites undergo melting. Our combined experimental-computational approach demonstrates that, on quenching, they form glasses that largely retain their solid-state inorganic-organic connectivity. The resulting materials show very low thermal conductivities (~0.2âW m-1 K-1), moderate electrical conductivities (10-3-10-5âS m-1) and polymer-like thermomechanical properties
ESKIMO1 Disruption in Arabidopsis Alters Vascular Tissue and Impairs Water Transport
Water economy in agricultural practices is an issue that is being addressed through studies aimed at understanding both plant water-use efficiency (WUE), i.e. biomass produced per water consumed, and responses to water shortage. In the model species Arabidopsis thaliana, the ESKIMO1 (ESK1) gene has been described as involved in freezing, cold and salt tolerance as well as in water economy: esk1 mutants have very low evapo-transpiration rates and high water-use efficiency. In order to establish ESK1 function, detailed characterization of esk1 mutants has been carried out. The stress hormone ABA (abscisic acid) was present at high levels in esk1 compared to wild type, nevertheless, the weak water loss of esk1 was independent of stomata closure through ABA biosynthesis, as combining mutant in this pathway with esk1 led to additive phenotypes. Measurement of root hydraulic conductivity suggests that the esk1 vegetative apparatus suffers water deficit due to a defect in water transport. ESK1 promoter-driven reporter gene expression was observed in xylem and fibers, the vascular tissue responsible for the transport of water and mineral nutrients from the soil to the shoots, via the roots. Moreover, in cross sections of hypocotyls, roots and stems, esk1 xylem vessels were collapsed. Finally, using Fourier-Transform Infrared (FTIR) spectroscopy, severe chemical modifications of xylem cell wall composition were highlighted in the esk1 mutants. Taken together our findings show that ESK1 is necessary for the production of functional xylem vessels, through its implication in the laying down of secondary cell wall components
Herkules â Held zwischen Tugend und Hybris. Ein europĂ€ischer Erinnerungsort der FrĂŒhen Neuzeit?
This essay traces some of the contexts and media in which "Heracles-Hercules" - as a hero between virtue and hubris - was visible in European societies from the end of the middle ages onwards. It discusses whether this example of the reception, appropriation and transformation of classical myths in the early modern period can be understood as a European "lieu de mémoire", and to what extent the concept of "lieux de mémoire" (or sites of memory) can foster our understanding of a particular object of study (here the Heracles/Hercules myth). Against this backdrop, we conclude with some general questions about the more ambitious project* of a comprehensive register of European "lieux de mémoire".
* * Published as: Boer, Pim den / Duchhardt, Heinz / Kreis, Georg / Schmale, Wolfgang (eds.): EuropĂ€ische Erinnerungsorte, 3 vols., Munich 2011â201
Attributable risk in men in two French case-control studies on mesothelioma and asbestos
Flexibility of a metal-organic framework enhances gas separation and enables quantum sieving
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