Breadmaking performance of protein enriched, gluten-free breads

9 pages, 3 figures, 5 tables.-- Published online 19 February 2008.-- The original publication is available at www.springerlink.comSoybean enriched, rice-based gluten-free breads were designed incorporating a structuring agent (hydroxypropylmethylcellulose, HPMC) and a processing aid (transglutaminase, TG). At dough level the effect of increasing amounts of soybean protein isolate (SPI), HPMC and water was studied in the Mixolab. Mixing and thermal characteristics showed the significant effect induced by water, soybean protein isolate, HPMC and TG, allowing the selection of the appropriate amounts for the breadmaking performance of enriched gluten-free breads. The single addition or in combination of 4% HPMC, 13% soybean and 1% TG produced significant changes in the physical properties of the rice-based gluten-free breads. The presence of SPI blended with rice flour produced a significant decrease in the specific volume of the bread, although this detrimental effect was partially counteracted by its combination with HPMC, decreasing also the crumb hardness. The micrographs of the crumb showed the beneficial effect of the HPMC, obtaining a more open aerated structure. Protein enriched, gluten-free breads can be obtained with a combination of SPI, HPMC and TG.This work was financially supported by Comisión Interministerial de Ciencia y Tecnología Project (MCYT, AGL2005-05192-C04-01) and Consejo Superior de Investigaciones Científicas (CSIC). C. Marco gratefully acknowledges the Ministerio de Educación y Ciencia for her grant.Peer reviewe

A single-crystal neutron and X-ray diffraction study of pezzottaite, Cs(Be2_{2}Li)Al2_{2}Si6_{6}O18_{18}

The chemical composition and the crystal structure of pezzottaite [ideal composition Cs(Be2Li) Al2Si6O18; space group: R3c, a = 15.9615(6) A ° , c = 27.8568(9) A ° ] from the type locality in Ambatovita (central Madagascar) were investigated by electron microprobe analysis in wavelength dispersive mode, thermo-gravimetric analysis, Fourier-transform infrared spectroscopy, single-crystal X-ray (at 298 K) and neutron (at 2.3 K) diffraction. The average chemical formula of the sample of pezzottaite resulted Cs1,Cs2(Cs0.565Rb0.027K0.017)R0.600 Na1,Na2(Na0.101Ca0.024)R0.125Be2.078Li0.922 Al1,Al2(Mg0.002 Mn0.002Fe0.003Al1.978)R1.985 Si1,Si2,Si3(Al0.056Si5.944)R6O18 0.27H2O. The (unpolarized) IR spectrum over the region 3,800–600 cm-1 was collected and a comparison with the absorption bands found in beryl carried out. In particular, two-weak absorption bands ascribable to the fundamental H2O stretching vibrations (i.e. 3,591 and 3,545 cm-1) were observed, despite the mineral being nominally anhydrous. The X-ray and neutron structure refinements showed: (a) a non-significant presence of aluminium, beryllium or lithium at the Si1, Si2 and Si3 sites, (b) the absence (at a significant level) of lithium at the octahedral Al1, Al2 and Al3 sites and (c) a partial lithium/beryllium disordering between tetrahedral Be and Li sites

A comprehensive study of the magnetic properties of the pyroxenes series CaMgSi₂O₆-Co₂Si₂O₆ as a function of Co content

We report a detailed study on the magnetic properties of the pyroxene series M2M1Si2O6, with M2 = Ca and M1 = Mg, where magnesium and then calcium are progressively substituted by cobalt. For cobalt site occupancy larger than 0.7 at the M1 site, a collinear antiferromagnetic phase is detected for T N1 = 12 K with a monodimensional character (i.e. M1 site intra-chain order parallel to c axis). Moreover the magnetization easy axis has been estimated to lie roughly along the [101] direction. Cobalt content ≥ 0.5 at the M2 site (overall content 1.5) determines the formation of a new independent antiferromagnetic order with higher Néel temperatures, involving only the M2 site intra-chain interactions. The incoming M2 site order is accompanied by a lowering of the space symmetry which yields to a weakly ferromagnetic resultant due to spin canted distribution of the magnetic moments either along the M1 or M2 chains. Furthermore, metamagnetic transitions are observed for both M1 and M2 site intra-chain orders at relatively low critical magnetic fields, around 2 T, suggesting that this series of pyroxenes can be used as model system for investigating the fundamental aspects of magnetism in the matter