Microwave-Assisted Extraction of Brewers' Spent Grain Arabinoxylans

Brewers´ spent grain (BSG) is a by-product from beer industry that can be exploited as a source of arabinoxylo-oligosaccharides (AXOS) with prebiotic activity. In this study, microwave-assisted extractions were performed during 2 min at 140-210°Cin order to evaluate the feasibility of this extraction technology for quantitative extraction of the arabinoxylans (AX) or AXOS from BSG. The AX yield increasedwith the increase of the temperature in the range used. The best condition of extraction of the AXwas 210 ºC during 2 min, allowing the extraction of 43% of total AX. These AX showed structural variability which allow to define specific types of compounds for different applications and uses depending on the extraction conditions used

Characterization of Plum Procyanidins by Thiolytic Depolymerization

The phenolic compounds of ?Green Gage? (GG) plums (Prunus domestica L.), ?Rainha Cla?udia Verde?, from a ?protected designation of origin? (PDO), in Portugal, were quantified in both flesh and skin tissues of plums collected in two different orchards (GG-V and GG-C). Analyzes of phenolic compounds were also performed on another GG European plum obtained in France (GG-F) and two other French plums, ?Mirabelle? (M) and ?Golden Japan? (GJ). Thiolysis was used for the first time in the analysis of plum phenolic compounds. This methodology showed that the flesh and skin contain a large proportion of flavan-3-ols, which account, respectively, for 92 and 85% in GJ, 61 and 44% in GG-V, 62 and 48% in GG-C, 54 and 27% in M, and 45 and 37% in GG-F. Terminal units of procyanidins observed in plums are mainly (+)-catechin (54?77% of all terminal units in flesh and 57?81% in skin). The GJ plums showed a phenolic composition different from all of the others, with a lower content of chlorogenic acid isomers and the presence of A-type procyanidins as dimers and terminal residues of polymerized forms. The average degree of polymerization (DPn) of plum procyanidins was higher in the flesh (5?9 units) than in the skin (4?6 units). Procyanidin B7 was observed in the flesh of all GG plums and in the skin of the Portuguese ones. Principal component analysis of the phenolic composition of the flesh and skin of these plums obtained after thiolysis allowed their distinction according to the variety and origin, opening the possibility of the use of phenolic composition for variety/origin identification

The elaboration of indices to assess biological water quality. A case study

Here we tested the application of a nodal analysis for the elaboration of biotic indices for particular stressing conditions. The work was carried out in an intermittent Mediterranean stream where superficial flow was absent during summer. The river was perturbed by an effluent with high pH, sulphates, nitrates and conductivity. "Summer" and "winter" samples were treated separately. We first identified groups of sites differing in taxonomical composition by cluster analysis. Then we tested whether groups of sites also differed in their abiotic characteristics. In the following step, groups of cooccurring taxa were also identified by cluster analysis. The indicator value of a taxa group was measured by fidelity measurements for site groups. Indicator taxa were incorporated in a water quality table. The biotic index in the water quality table clearly discriminated impacted from reference sites in the two following years and was correlated with the first axis of a correspondence analysis biplot which also discriminated impacted from clean sites. We suggest that nodal analysis can be a reliable technique for the identification of bioindicators and the elaboration of biotic indices.http://www.sciencedirect.com/science/article/B6V73-3SX5H1V-F/1/2ddcd6137e173976c270b458bbb4c99

The elaboration of indices to assess biological water quality. A case study

Here we tested the application of a nodal analysis for the elaboration of biotic indices for particular stressing conditions. The work was carried out in an intermittent Mediterranean stream where superficial flow was absent during summer. The river was perturbed by an effluent with high pH, sulphates, nitrates and conductivity. "Summer" and "winter" samples were treated separately. We first identified groups of sites differing in taxonomical composition by cluster analysis. Then we tested whether groups of sites also differed in their abiotic characteristics. In the following step, groups of cooccurring taxa were also identified by cluster analysis. The indicator value of a taxa group was measured by fidelity measurements for site groups. Indicator taxa were incorporated in a water quality table. The biotic index in the water quality table clearly discriminated impacted from reference sites in the two following years and was correlated with the first axis of a correspondence analysis biplot which also discriminated impacted from clean sites. We suggest that nodal analysis can be a reliable technique for the identification of bioindicators and the elaboration of biotic indices.http://www.sciencedirect.com/science/article/B6V73-3SX5H1V-F/1/2ddcd6137e173976c270b458bbb4c99

A Challenging Abdominal Pain

info:eu-repo/semantics/publishedVersio

Caracterização dos polissacarídeos das paredes celulares da grainha de uva com vista à valorização do óleo por aplicação de enzimas exógenas

ISBN 972-9372-29-