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| Alves,Ricardo; Reis,Thaís Vitória da Silva; Silva,Luis Carlos Cides da; Storpírtis,Silvia; Mercuri,Lucildes Pita; Matos,Jivaldo do Rosário. |
| The thermal behavior of two polymorphic forms of rifampicin was studied by DSC and TG/DTG. The thermoanalytical results clearly showed the differences between the two crystalline forms. Polymorph I was the most thermally stable form, the DSC curve showed no fusion for this species and the thermal decomposition process occurred around 245 ºC. The DSC curve of polymorph II showed two consecutive events, an endothermic event (Tpeak = 193.9 ºC) and one exothermic event (Tpeak = 209.4 ºC), due to a melting process followed by recrystallization, which was attributed to the conversion of form II to form I. Isothermal and non-isothermal thermogravimetric methods were used to determine the kinetic parameters of the thermal decomposition process. For non-isothermal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rifampicin; Tuberculosis; Thermal analysis; Thermal decomposition; Kinetic analysis. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000200022 |
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| JAIMEZ-ORDAZ,Judith; PÉREZ-FLORES,Jesús Guadalupe; CASTAÑEDA-OVANDO,Araceli; GONZÁLEZ-OLIVARES,Luis Guillermo; AÑORVE-MORGA,Javier; CONTRERAS-LÓPEZ,Elizabeth. |
| Abstract In food systems, lipid oxidation is one of the most important factors affecting food quality, nutrition, safety, color and consumer acceptance. The objective of this study was to determine the kinetic parameters of lipid oxidation and its influence in the shelf life of third generation (3G) snacks stored in three types of packaging (polyethylene, polypropylene + Kraft paper, and polyethylene + polypropylene) at 25 °C and 40 °C. The peroxide value was the quality parameter selected and monitored for a 60 day period using a spectrophotometric technique. Based on the Arrhenius equation and activated complex theory, reaction rate constants (k), activation energies (Ea), Q10 factors, activation enthalpies (∆H‡), and activation entropies (∆S‡ ) for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Shelf life; 3G snacks; Peroxide value; Packaging materials; Kinetic analysis. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612019000500136 |
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