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Methanol extracts of olive pomace (two-phase olive oil extraction) and olive pulp were analysed by reverse phase HPLC and the eluted fractions were characterised by electrospray ionisation mass spectrometry. This technique allowed the identification of some common phenolic compounds, namely, verbascoside, rutin, caffeoyl-quinic acid, luteolin-4-glucoside and 11-methyl-oleoside. Hydroxytyrosol-1 -β-glucoside, luteolin-7-rutinoside and oleoside were also detected. Moreover, this technique enabled the identification, for the first time in Olea europaea tissues, of two oleoside derivatives, 6 -β-glucopyranosyloleoside and 6 -β-rhamnopyranosyl-oleoside, and of 10-hydroxy-oleuropein. Also, an oleuropein glucoside that had previously been identified in olive leaves was now detected in olive fruit, both in olive pulp and olive pomace. With the exception of oleoside and oleuropein, the majority of phenolic compounds were found to occur in equivalent amounts in olive pulp and olive pomace. Oleoside was the main phenolic compound in olive pulp (31.6 mg g −1 ) but was reduced to 3.6 mg g −1 in olive pomace, and oleuropein (2.7 mg g −1 in the pulp) almost disappeared (<0.

This study describes the preparation and characterization of nanofibrous mats obtained by electrospinning poly(ethylene terephthalate) (PET) solutions in trifluoroacetic acid/dichloromethane (TFA/DCM). Special attention was paid to the effect of polymer concentration and solvent properties on the morphology, structure, and mechanical and thermal properties of the electrospun nonwovens. The results show that the spinnable concentration of PET solution in TFA/DCM solvents is above 10 wt %. Mats have nanofibrous morphology with fibers having an average diameter in the range of 200–700 nm (depending on polymer concentration and solvent composition) and an interconnected pore structure. Higher solution concentration favors the formation of uniform fibers without beads and with higher diameter. Morphology and fiber assembly changed with the solvent properties. Solvent mixtures rich in TFA, i.e., those with higher dielectric constant and lower surface tension, originated fibers with small diameter. However, due to the lower volatility, those solvent mixtures also produced more branched and crosslinking fibers, with less morphologic uniformity. Mechanical properties (Young's modulus, ultimate strength, and elongation at break) and thermal properties (glass transition, crystallization, and melting) have been studied for the PET electrospun nanomats and compared with those of the original polymer. Solvent effect on fiber crystallinity was not significant, but a complex effect was observed on the mechanical properties of the electrospun mats, as a consequence of the different structural organization of the fibers within the mat network. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 460–471, 2008

Ionic liquids (ILs) with improved hydrogen-bonding acceptor abilities, such as acetate-based compounds, have shown great potential for CO 2 capture and biomass dissolution. In this context, the knowledge of the thermophysical properties of acetate-based fluids is essential for the design and scale-up of related processes. However, at this stage, acetate-based ILs are still poorly characterized. In this work, four thermophysical properties, specifically, density, viscosity, refractive index, and surface tension, were determined for five acetate-based ILs. Both protic and aprotic ILs were investigated, namely, N,N-dimethyl-N-ethylammonium acetate, 1-ethylimidazolium acetate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-1-methylpyrrolidinium acetate. From the temperature dependence of the measured properties, additional properties, such as the isobaric thermal expansion coefficient, the surface entropy and enthalpy, and the critical temperature, were further estimated. ■ INTRODUCTIONDuring the past decade research has emerged in various areas involving ionic liquids (ILs), and their potential applications are nowadays widespread. Ionic liquids are a group of molten salts normally composed of inorganic or organic anions, and relatively large organic cations, which do not easily form an ordered crystal and, therefore, they remain liquid at or near room temperature. 1−3 Recently, certain classes of ILs with improved hydrogenbonding acceptor capability, such as acetate-based fluids, have shown to be promising solvents for CO 2 capture 4−7 and cellulose and/or biomass dissolution. 8−11 Acetate-based fluids are able to strongly coordinate with CO 2 and hydrogen bond donator groups, such as −OH groups, and favorable results have thus been published. Moreover, acetate-based ILs present low toxicity, low corrosiveness, and favorable biodegradability. 12 Despite their undeniable interest, the thermophysical properties of acetate-based fluids are still poorly characterized. In a previous work we have determined the densities and viscosities of a series of imidazolium-based ILs which have shown potential for the dissolution of biomass. 13 Fendt et al. 14 presented the viscosities of acetate-based ILs and some of their mixtures with water and organic solvents. Qian et al. 15 explored the densities and viscosities of the protic IL 1-methylimidazolium acetate and its binary mixtures with alcohols. Additional scarce reports have addressed the measurements of densities, 16−18 viscosities, 19 refractive index, 16,20 and surface tension 18 of aprotic acetate-based ILs.In this work, the thermophysical properties of acetate-based ILs, specifically density, viscosity, refractive index, and surface tension, were measured as a function of temperature. The ILs are formed by the common anion acetate, combined either with protic (N,N-dimethyl-N-ethylammonium and 1-ethylimidazolium) or aprotic cations (1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium and 1-butyl-1-methylpyrrolydinium). Additio...

The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to wrap cheeses, throughout 60 d of storage, as an alternative to commercial nonedible coatings. Coatings were prepared using whey protein isolate, glycerol, guar gum, sunflower oil, and Tween 20 as a base matrix, together with several combinations of antimicrobial compounds-natamycin and lactic acid, natamycin and chitooligosaccharides (COS), and natamycin, lactic acid, and COS. Application of coating on cheese decreased water loss (~10%, wt/wt), hardness, and color change; however, salt and fat contents were not significantly affected. Moreover, the antimicrobial edible coatings did not permit growth of pathogenic or contaminant microorganisms, while allowing regular growth of lactic acid bacteria throughout storage. Commercial nonedible coatings inhibited only yeasts and molds. The antimicrobial edible coating containing natamycin and lactic acid was the best in sensory terms. Because these antimicrobial coatings are manufactured from food-grade materials, they can be consumed as an integral part of cheese, which represents a competitive advantage over nonedible coatings.