Effect of fructooligosaccharides on the physicochemical properties of sour cassava starch and baking quality of gluten-free cheese bread

The present research was undertaken to explore the influence of fructooligosaccharides (FOS) on the functional and thermal properties of sour cassava starch and the quality characteristics of gluten-free (GF) cheese bread. Fructooligosaccharides were used to replace sour cassava starch at substitution level of 9% (SF1), 17% (SF2), and 29% (SF3). The functional and thermal properties of the starch-FOS mixtures were determined by the water absorption index (WAI), water solubility index (WSI), pasting profile analysis, thermal transition temperatures and enthalpy of gelatinization. Moreover, the GF cheese breads with starch-FOS mixtures were analyzed for height, diameter, weight, specific volume and dough moisture content. The sample with the highest FOS content (SF3) presented the lowest WAI (1.44), peak (62.4 rapid visco units (RVU), breakdown (53.4 RVU), final (13.8 RVU), and setback (4.9 RVU) viscosities, dough moisture content (31.7%), and enthalpy of gelatinization (9.5 J/g) and the highest WSI (29.4%) and pasting temperature (69.1 degrees C). The height, diameter and specific volume of GF cheese bread samples made from sour cassava starch were 3.14 cm, 6.35 cm, and 1.49 cm(3)/g, respectively. The SF1 mixture samples resulted in a 3.01 cm height, 6.34 cm diameter, and 1.55 cm(3)/g specific volume. According to Brazilian food labeling regulations, the latter product cannot be categorized as a good source of fiber because the minimum level of fiber per portion was not reached.

Thermal and structural study of glasses in the binary system TeO2-Pb(PO3)(2)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermal Characteristics of Lignin Residue from Industrial Processes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prediction of the combustion process in fluidized bed based on physical-chemical properties of biomass particles and their hydrodynamic behaviors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological, thermal and physicochemical characteristics of small granules starch from Mirabilis jalapa L

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Third-order nonlinearities and other properties of molybdenum lead-pyrophosphate glass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Graded meshes in bio-thermal problems with transmission-line modeling method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physico-chemical properties of starches isolated from potato cultivars grown in soils with different phosphorus availability

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermal and spectroscopic studies of the antioxidant food additive propyl gallate

Literature mentions propyl gallate (PG) as a non-toxic synthetic antioxidant that can be used as a food additive due to its high tolerance to heat. It is important to understand the thermal properties and to identify the decomposition products of this substance, since it has been reported to be thermally stable at temperatures as high as 300 °C. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry-photovisual (DSC-photovisual), coupled thermogravimetry-infrared spectroscopy (TG-FTIR) analyses and spectroscopic techniques were used to study the food additive PG. The TG-DTA curves, which were performed with the aid of DSC-photovisual, provided information concerning the thermal stability and decomposition profiles of the compound. From the TG-FTIR coupled techniques, it was possible to identify n-propanol as a possible volatile compound released during the thermal decomposition of the antioxidant. A complete spectroscopic characterization in the ultraviolet, visible, near and middle infrared regions was performed in order to understand the spectroscopic properties of PG.

Toward an understanding of intermediate- and short-range defects in ZnO single crystals. A combined experimental and theoretical study

A joint use of experimental and theoretical techniques allows us to understand the key role of intermediate- and short-range defects in the structural and electronic properties of ZnO single crystals obtained by means of both conventional hydrothermal and microwave-hydrothermal synthesis methods. X-ray diffraction, Raman spectra, photoluminescence, scanning electronic and transmission electron microscopies were used to characterize the thermal properties, crystalline and optical features of the obtained nano and microwires ZnO structures. In addition, these properties were further investigated by means of two periodic models, crystalline and disordered ZnO wurtzite structure, and first principles calculations based on density functional theory at the B3LYP level. The theoretical results indicate that the key factor controlling the electronic behavior can be associated with a symmetry breaking process, creating localized electronic levels above the valence band.

Efeitos da história térmica nas propriedades do polímero pet: um experimento para ensino de análise térmica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photopyroelectric spectroscopy of polyaniline films

Photopyroelectric spectroscopy (PPES), in the 400 < lambda < 900 nm wavelength range, was used to study thermal properties of differently doped polyaniline (PAN) films. The photopyroelectric intensity signal V-n(lambda) and its phase F-n(lambda) were independently measured, as well as the intensity V-n(f) and the phase F-n(f) (f being the chopping frequency) for a given A of the saturation part of the PPES spectrum. Equations of both the intensity and the phase of the PPES signal, taking into account the thermal and the optical characteristics of the PAN films and the pyroelectric detector, were used to fit the experimental results. From the fittings we obtained, with great accuracy, the values of thermal conductivity k and thermal diffusivity coefficient a of PAN films of different doping degrees. It was observed that, in contrast with the strong doping-dependence of the electrical conductivity, the thermal parameters of PAN films remained practically unchanged under doping. This apparent discrepancy is explained by the granular metal model of doped PAN. (C) 2000 John Wiley & Sons, Inc.

Undoped and calcium doped borate glass system for thermoluminescent dosimeter

Borate glasses present an absorption coefficient very close to that of human tissue. This fact makes some borates ideal materials to develop medical and environmental dosimeters. Glass compositions with calcium tetraborate (CaB4O7) and calcium metaborate (CaB2O4), such as the xCaB(4)O(7) - (100-x)CaB2O4 System (0 <= x <= 100 wt%) were obtained by the traditional melting/quenching method. A phenomenon widely known as the 'boron anomaly' was observed in our thermal analysis measurements, as indicated by the increase of T, and the appearance of a maximum value in the composition with 40 wt% of CaB2O4. The Dy doped and Li co-doped 80CaB(4)O(7)-20CaB(2)O(4) (Wt%) glass samples were studied by the thermoluminescence technique. The addition of Dy improved the signal sensitivity in about three times with respect to the undoped glass sample. The addition of Li as a co-dopant in this glass caused a shift to a lower temperature of about 20 degrees C in the main glow peak. The structural analysis of the 80CaB(4)O(7)-20CaB(2)O(4) (wt%) undoped and doped samples were studied through infrared absorption. We have noted an increase in the coordination number of the boron atoms from 3 to 4, i.e., the conversion of the BO3 triangular structural units into BO4 tetrahedra. (c) 2006 Elsevier B.V. All rights reserved.

NON-ISOTHERMAL STUDIES on CRYSTALLIZATION KINETICS of TELLURITE 20Li(2)O-80TeO(2) GLASS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Continuous and gradual photo-activation methods: influence on degree of conversion and crosslink density of composite resins

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)