Thermoanalytical study of inner and outer residue of coffee harvest

The better use of agricultural residues is expected, when they are mostly disposed of improperly and it is often burned in the natural environment. This study of the thermal decomposition of residues was performed from the coffee crop for energy purposes and in this case was used thermal analysis techniques for such assessment. the TG/DTG and DSC curves showed that the thermal decomposition occurs in four consecutive events and it is predominantly exothermic. the first mass loss evidenced in TG/DTG curves has an endothermic peak in DSC curve, which it can be associated with the water liberation of the material. This first thermal event also can be related to the liberation of volatile compounds present in the sample, which is also corroborated by the endothermic peak. the other events of mass loss are related with the thermal decomposition of the material. This decomposition has an exothermic behavior, which is positively applied to the main aim of this scientific research: the coffee straw use like biomass energy font. the thermoanalytical techniques were satisfactory in the characterization of this material.IPEN CNEN SP, BR-05508000 São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniv São Paulo, Inst Chem, São Paulo, BrazilFederal University of São Paulo, Campus Diadema, São Paulo, BrazilWeb of Scienc

Stability evaluation of tocopheryl acetate and ascorbyl tetraisopalmitate in isolation and incorporated in cosmetic formulations using thermal analysis

In view of the increase in the number of cosmetic preparations containing antioxidant vitamins, chiefly, due to their action in preventing the process of skin aging, there is a need to develop pre-formulation studies and to validate analytical methods in order to obtain high quality products. Thus, the objective of this research was to evaluate and compare the thermal behavior of tocopheryl acetate and ascorbyl tetraisopalmitate as raw materials, and incorporated into a base cream. Thermogravimetry (TG / DTG) and differential scanning calorimetry (DSC) were used for this purpose. Both vitamins were found to be stable up to 250ºC. The base cream (placebo) and the sample (base cream containing the vitamins) presented different weight loss. Thermal analysis has shown itself to be an excellent tool for the characterization of these vitamins and can be used in routine analysis for quality control of this type of cosmetic formulation.<br>Considerando o potencial antioxidante das vitaminas utilizadas em produtos cosméticos, seu uso na prevenção do processo de envelhecimento da pele e a necessidade de estudos de pré-formulação que garantam o desenvolvimento de cosméticos de qualidade, foi objetivo deste trabalho avaliar e comparar o comportamento térmico dos ativos acetato de tocoferila e tetraisopalmitato de ascorbila, matérias-primas, isoladamente e incorporados em creme base. As técnicas termogravimetria/termogravimetria derivada (TG/DTG) e calorimetria exploratória diferencial (DSC) foram utilizadas para tal finalidade. Verificou-se que as vitaminas mantiveram-se estáveis até a temperatura de, aproximadamente, 250 ºC, observando-se diferença na perda de massa entre o creme base e o creme base associado às vitaminas. Assim sendo, a análise térmica mostrou-se como excelente ferramenta para caracterização das vitaminas e do creme base, podendo ser empregada em análises de rotina no controle de qualidade deste tipo de formulação cosmética

Characterization and evaluation of free and nanostructured ursolic acid incorporated in cosmetic formulation using thermal analysis

The ursolic acid (UA) increases the skin's barrier function and acts in epidermal differentiation of keratinocytes in the epidermis, promoting cell renewal. Besides the mentioned properties UA also has antioxidant, antimicrobial, and anti-irritant functions to cosmetic formulations. Thus, it is necessary formulation studies to insure the development of quality cosmetic products containing this active, increasing its antioxidant potential within nanoparticles. This study aims to characterize and evaluate the thermal behavior of UA in free and nanostructured forms, and both incorporated into a cosmetic base formulation, using thermogravimetry and differential scanning calorimetry. Through the study were observed that free UA, in the embedded nanoparticles and in base formulation exhibited different behavior in similar thermal profile and relative to the presence of UA. the UA remained stable to a temperature of 250 A degrees C and the technique has been shown to be effective for characterizing UA, evaluate water content, and stability of the formulation base.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Fac Pharmaceut Sci, Dept Pharm, USP SP, BR-05508900 São Paulo, BrazilUniv São Paulo, Dept Fundamental Chem, Inst Chem, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Exact & Earth Sci, Fac Chem, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Exact & Earth Sci, Fac Chem, BR-09972270 Diadema, SP, BrazilWeb of Scienc