Non-starch polysaccharides in beer and brewing: A review of their occurrence and significance.

It has become apparent that beer (both alcoholic and nonalcoholic) contains appreciable amounts of non-starch polysaccharides, a broad subgroup of dietary fiber. It is worth noting that the occurrence of non-starch polysaccharides in alcoholic beer does not imply this should be consumed as a source of nutrition. But the popularity of nonalcoholic beer is growing, and the lessons learnt from non-starch polysaccharides in brewing can be largely translated to nonalcoholic beer.

Statistical Thermodynamics Unveils How Ions Influence an Aqueous Diels-Alder Reaction.

The kinetics of Diels-Alder (DA) reactions in water has been known to be altered by salts for a long time. Yet the question how salts influence the reaction rate, either as rate-enhancing or rate-reducing additives, has so far remained unresolved. Conflicting hypotheses involve (i) indirect salt contributions through the modulation of internal pressure and (ii) making (or breaking) of the so-called "water-structure" by salts that strengthen (or weaken) the hydrophobic effect.

Structure-property relationships in protic ionic liquids: a study of solvent-solvent and solvent-solute interactions.

The ionic nature of a functionalized protic ionic liquid cannot be rationalized simply through the differences in aqueous proton dissociation constants between the acid precursor and the conjugate acid of the base precursor. The extent of proton transfer, i.e.

Structure-property relationships in protic ionic liquids: a thermochemical study.

How does cation functionality influence the strength of intermolecular interactions in protic ionic liquids (PILs)? Quantifying the energetics of PILs can be an invaluable tool to answer this fundamental question. With this in view, we have determined the standard molar enthalpy of vaporization, , and the standard molar enthalpy of formation, , of three tertiary ammonium acetate PILs with varying cation functionality, and of their corresponding precursor amines, through a combination of Calvet-drop microcalorimetry, solution calorimetry, and ab initio calculations. The obtained results suggest that these PILs vaporize as their neutral acid and base precursors.

The properties of residual water molecules in ionic liquids: a comparison between direct and inverse Kirkwood-Buff approaches.

We study the properties of residual water molecules at different mole fractions in dialkylimidazolium based ionic liquids (ILs), namely 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM/BF) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM/BF) by means of atomistic molecular dynamics (MD) simulations. The corresponding Kirkwood-Buff (KB) integrals for the water-ion and ion-ion correlation behavior are calculated by a direct evaluation of the radial distribution functions. The outcomes are compared to the corresponding KB integrals derived by an inverse approach based on experimental data.

Interactions in Water-Ionic Liquid Mixtures: Comparing Protic and Aprotic Systems.

The sensitivity of ionic liquids (ILs) to water affects their physical and chemical properties, even at relatively low concentrations, yet the structural thermodynamics of protic IL- (PIL-) water systems at low water concentrations still remains unclear. Using the rigorous Kirkwood-Buff theory of solutions, which can quantify the interactions between species in IL-water systems solely from thermodynamic data, we have shown the following: (1) Between analogous protic and aprotic ILs (AILs), the AIL cholinium bis(trifluoromethanesulfonyl)imide ([Ch][NTf]) shows stronger interactions with water at low water concentrations, with the analogous PIL N,N-dimethylethanolammonium bis(trifluoromethanesulfonyl)imide ([DMEtA][NTf]) having stronger water-ion interactions at higher water contents, despite water-ion interactions weakening with increasing water content in both systems. (2) Water has little effect on the average ion-ion interactions in both protic and aprotic ILs, aside from the AIL [Ch][NTf], which shows a strengthening of ion-ion interactions with increasing water content.

Residual water in ionic liquids: clustered or dissociated?

How do residual water molecules in ionic liquids (ILs) interact with themselves, as well as with the ions? This question is crucial in understanding why the physical properties of ILs--and chemical reactions performed in them--are strongly affected by the residual water content. There have been three conflicting hypotheses regarding the structure and behaviour of the residual water: (i) water molecules are separated from one another, while interacting strongly with the ions, and dispersed throughout the medium; (ii) water molecules self-associate or form clusters in the ILs; (iii) residual water weakens ion-ion interactions. A satisfactory resolution of these conflicting suggestions has been hindered by the complexity and long range of the interactions in the water-IL mixture and by the often profound differences in physical structure between various different ILs.