Estudo dos efeitos da radiação ultravioleta nas propriedades termogravimétricas de amido de mandioca oxidado por hipoclorito de sódio.

Resumo

TG-DTA and DSC investigations of ''pinhão'' starch modified by calcium hypochlorite and UV light.

Starches, when in its native forms, usually do not have the characteristics required for industrial processing. ''Pinhão'', a seed from the Araucaria angustifolia tree, has starch as main presenting as a great alternative source of starch. Samples of native ''pinhão'' starch were treated with standard calcium hypochlorite solutions (0.1, 0.2 and 0.5 mol L-1) and exposed for one hour under UV light. The modification process applied altered the thermal behavior of the ''pinhão'' starch as the TGA-DTA and DSC results presented.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru

Induced effects of oxidation with potassium permanganate in the modification of corn starch.

CBRATEC

Thermal and rheological behavior of native and modified starch Araucaria angustifolia (pinhão).

Araucaria angustifolia is known in Brazil as Paraná Pine is endangered due to reckless extraction. The preservation and maintenance of the culture could be stimulated by use derivative products like the starch from its seeds (pinhão). In this work were studied samples of unmodified and modified pinhão starch. The hydrogen peroxide (H2O2) were used in the concentrations 0.1, 0.2 and 0.3 mol.L-1 (a, b, c) and simultaneously exposed in ultraviolet rays (λ = 256 nm) for one hour. One sample (N) was maintained as received for comparisons of the analysis results. The samples were analyzed by the thermoanalytical techniques: thermogravimetry and differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC); and by the rheological analysis: Rapid Viscoamylographic Analysis (RVA). The TGA showed an increase on the stability values form the (N) sample to the modified ones. The DSC showed a strong decrease on the gelatinization enthalpy with increasing of the H2O2 concentrations solutions valued for the modified samples. The RVA results presented that the Setback reduced with the treatment that used hydrogen peroxide in a higher concentration. The obtained results showed that the modification method applied altered the thermal behavior of the pinhão starch.CBRATEC

Caracterização de grande número de amostras de madeira de pinus visando aplicação em seleção genômica ampla.

Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos

Simultaneous TG-DTA and DSC techniques on pinhão starch double modified.

The “pinhão” is the seed of Araucaria angustifolia (known as Paraná pine). This specie is in danger due to reckless exploration. Thus, the development of new applications could motivate its preservation. Samples of native “pinhão” starch were oxidized with standard NaClO solutions (0.1, 0.2 and 0.5 mol L-1) and exposed for one hour under UV light (UVC radiation with ? = 256 nm). The TG curves showed similar behavior. The oxidative modification caused a decrease in the gelatinization enthalpy (DSC).Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru

Effect of treatment with hcl/alcoholic in the modification of corn starch.

Corn is the cereal most produced in the world. Corn starches were modified by HCl 0.1 mol L-1 in alcoholic and aqueous solutions. Three mass losses can be observed in the degradation process using TG-DTG curve. The native and treated starches samples don't show differences in the stability region. With DSC curves were observed lower values of the ΔH of gelatinization of the modified starch by HCl in the alcoholic solutions. The modifications using alcoholic solutions demonstrated a good alternative to obtain modifies starches.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru