Physicochemical, calorimetric and texture profile characteristics of various gluten-free flours.

It is important to understand how the composition and structure of proteins from other flours differ from proteins in wheat, in order to have a better option to substitute gluten products with gluten-free food products. The aim of this study was the characterization of gluten-free flours and comparison of their rheological and calorimetric properties against wheat flour, for its use as gluten-free alternative. Chemical composition analysis, water solubility index (WSI), water absorption index (WAI), texture and calorimetric profile were determined. The closest WAI to wheat flour (1.45 g gel/g sample) was corn flour (2.41 g gel/g sample), while the WSI of chickpea flour was 5.51% approaching that of wheat flour of 5.88%. The hardness and adhesiveness values closest to wheat (1.65 kgf and 0.03 mJ) were amaranth flour with 0.85 kgf and 0.01 mJ, respectively. The phenolic content and antioxidant capacity were higher in the corn and bean flours with 244.4 mg GAE/100 g, 148 mg GAE/100 g and 190 mg AAE/100 g and 170 mg AAE/100 g, respectively. The combination of these non-conventional flours can be an innovative source of gluten-free formulas.

Electricity generation from Nopal biogas effluent using a surface modified clay cup (cantarito) microbial fuel cell.

A modified clay cup (cantarito) microbial fuel cell (C-MFCs) was designed to digest the biomass effluent from a nopal biogas (NBE). To improve the process, commercial acrylic varnish (AV) was applied to the C-MFCs. The experiment was performed as:Both-C-MFCs, painting of AV on both sides of the clay cup; In-C-MFCs, painting of AV on the internal side, and Out-C-MFCs painting of AV on the external side. The order for the maximum volumetric power densities were Both-C-MFCs (1841.99 mW/m3)>Out-C-MFCs (1023.74 mW/m3) >In-C-MFCs (448.90 mW/m3). The control experiment without applied varnish did not show a stable potential, supporting the idea that the acryloyl group in varnish could favor the performance. Finally, a 4-digits clock was powered with two, Both-C-MFCs connected in series; the microbial diversity in this format was explored and a well-defined bacterial community including members of the phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, Synergistetes and candidate division TM7 was found.