A parametric and microstructural study of the formation of gluten network in mixed flour–water batter

The mechanism of gluten network development is still unclear and remains difficult to study since gluten network formation in bread dough is a rather quick process. In order to better characterize this dynamic event, we slowed down its kinetics by increasing the dough water content. During mixing, performed with a planetary mixer at variable mixing speeds and flour/water ratios, the torque was recorded. Common flours from wheat cultivars Orvantis, Caphorn and Isengrain, similar in composition and Farinograph parameters, were studied.     

Montenegro's skin reactions and antibodies against different Leishmania species in dogs from a visceral leishmaniosis endemic area

In this study, humoral (circulating anti-Leishmania antibodies) and cellular (Montenegro's skin test) immune responses of dogs from an endemic area of visceral leishmaniosis were tested using Leishmania chagasi, Leishmania amazonensis and Leishmania braziliensis antigens. The antibody response was tested in three animal groups, selected according to their anti-L. chagasi antibody activity, as measured by ELISA in the serum: 19 negative (O.D. below 0.30), seven with undefined (O.D. between 0.40 and 0.70) and 12 positive (O.D. above 1.0) ELISA result. In the group of animals with positive ELISA, the antibody activity against L. chagasi antigens (mean O.D.=1.31) was significantly higher (ANOVA, P<0.01) than against L. amazonensis (mean O.D.=0.88) or L. braziliensis (mean O.D.=0.87) antigens. The Montenegro's skin test results obtained with L. chagasi and L. braziliensis antigens showed a fair agreement (kappa=0.309). The same was observed when antigens from L. braziliensis and L. amazonensis were compared (kappa=0.374), whereas a moderate agreement between the results from tests performed with L. chagasi and L. amazonensis antigens was observed (kappa=0.530). The induration areas obtained with L. braziliensis antigen were smaller than those obtained with the other antigens. The data presented herein indicate that the use of antigens from different Leishmania species may interfere with the results of the immunological tests performed in dogs in an endemic area of visceral leishmaniosis.     

The use of some agricultural fertilizers for the mass production of marine algae

Three Brazilian and 9 French agricultural fertilizers were compared with Conway mixture, as nutrient enrichment for supporting the growth of 16 marine algae. Fertilizers containing only nitrogen and phosphorus appeared to be suitable. However, a few algae grew better in all-nutrient-enriched Conway medium. Addition of chelators did not generate better growth. Matrix-free fertilizers were found more convenient in use. A table is given to show the cheapest and/or best nutrient enrichment for each algal strain tested.     

Effect of environmental conditions on the seasonal and inter‐annual variability of small pelagic fish abundance off North‐West Africa: The case of both Senegalese sardinella

The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Niño Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance of sardinella is determined by a strong seasonal pattern and inter‐annual fluctuations. The abundance of S. aurita peaked in spring and in autumn, whereas that of S. maderensis peaked in the warm season (July–September). The trend of the sardinella abundance was significantly correlated with the CUI, especially in autumn and spring. Interannual fluctuations of S. maderensis and S. aurita abundance are, respectively, driven by the precocity and the duration of the upwelling season that is attributed to distinct migration patterns. Both sardinella species also respond with a delay of around 4 years to the winter NAO index and the autumn CUI, and the AMO index, respectively, both related to migration patterns. The wide variations in sardinella biomass are caused by variations in environmental conditions, which should be considered in the implementation of an ecosystem‐based approach in sardinella stocks management.     

Changes in green coffee protein profiles during roasting

To reveal its flavor, coffee has to be roasted. In fact, the green coffee bean contains all ingredients necessary for the later development of coffee flavor. It is now widely accepted that free amino acids and peptides are required for the generation of coffee aroma. However, the mechanisms leading to defined mixtures of free amino acids and peptides remain unknown. Information pertaining to the identification of precursor proteins is also lacking. To answer some of these questions, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used to follow the fate of green coffee proteins. Two conditions were considered: roasting and incubation of green coffee suspensions at 37 degrees C. Coffee beans were observed to acquire the potential to spontaneously release H(2)O(2) upon polymerization of their proteins during roasting. Fragmentation of proteins was also observed. Conversely, H(2)O(2) was found to control polymerization and fragmentation of green coffee proteins in solution at 37 degrees C. Polymerization and fragmentation patterns under the two conditions were comparable. These observations suggest that the two conditions under study triggered, at least to some extent, similar biochemical mechanisms involving autoxidation. Throughout this study, a unique fragmentation cascade involving the 11S coffee storage protein was identified. Generated fragments shared an atypical staining behavior linked to their sensitivity to redox conditions.     

Immunoglobulin E-bearing cells and mast cells in skin biopsies of horses with urticaria

The pathogenesis of equine urticaria is not well understood. In man, urticaria has been associated with immunological and nonimmunological mechanisms leading to the release of various mediators by mast cells. Skin biopsies of 32 horses with a history of urticaria were stained with toluidine blue, a double-labelling method for chymase and tryptase, and immunohistochemistry for immunoglobulin (Ig)E. These horses were compared with horses with pemphigus foliaceus, insect bite hypersensitivity and control horses with healthy skin. Neither formalin fixation time nor biopsy site influenced the staining methods. No chymase-positive cells were found. In all groups of horses, cells staining with toluidine blue and for tryptase and IgE were found in the epidermis and hair follicle papilla and significantly more positively staining cells were observed in the subepidermal dermis compared with the deep dermis. Horses with urticaria had significantly more IgE-bearing cells in the subepidermal dermis than control horses. However, horses with urticaria had significantly fewer toluidine-blue-stained mast cells in both subepidermal and deep dermis compared with the insect bite hypersensitivity and pemphigus foliaceus groups. This study suggests that IgE-mediated reactions play a role in the pathogenesis of urticaria.