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Journal of Thermal Analysis and Calorimetry - Cupuassu (Theobroma grandiflorum Schum.) is a typical Amazonian fruit, whose seed is used as raw material to produce cupulate. The by-product of its...  相似文献   
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Cupuassu (Theobroma grandiflorum Schum.) is a popular Amazonian fruit because of its intense aroma and nutritional value, whose lipid fraction is alternatively used in cosmetics. To preserve active principles and ensure their controlled release, extract was microencapsulated by spray drying. Influence of spray-drying conditions on microencapsulation of cupuassu seed by-product extract was investigated according to a 33-Box Behnken factorial design, selecting inlet temperature, maltodextrin concentration and feed flowrate as independent variables, and total polyphenol and flavonoid contents, antiradical power, yields of drying and microencapsulation as responses. Fitting the results by second-order equations and modelling by Response Surface Methodology allowed predicting optimum conditions. Epicatechin and glycosylated quercetin were the major microencapsulated flavonoids. Microparticles showed satisfactory antiradical power and stability at 5 °C or under simulated gastrointestinal conditions, thus they may be used to formulate new foods or pharmaceuticals.  相似文献   
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Thermogravimetric (TG) techniques and differential scanning calorimetry (DSC) used for the study of pre-formulation or drug–adjuvant compatibility have been gaining importance in Brazil. These techniques are being used for the verification of possible interactions between drugs and adjuvants. Aiming at studying the behavior of a plant extract and its mixture with adjuvants, using these thermoanalytical techniques the plant species Heliotropium indicum L. was used. This plant which is originally from India and has been well acclimatized in Brazil has healing and anti-inflammatory properties. The methodology for obtaining the extract followed the Brazilian Pharmacopoeia methodology. And the incorporation of the extract with adjuvants was through binary mixtures (1:1 w/w). The TG and DSC curves were obtained under nitrogen atmosphere (25 mL min?1) at a heating rate of 5 °C min?1; TG tests were analyzed within a temperature range from 25 to 600 °C and DSC from 25 to 300 °C. The TG curves show good thermal stability of the extract and its mixtures with adjuvants up to 150 °C, except the propylene glycol (PLG). The DSC curves revealed an incompatibility of the extract with methylparaben and PLG mixture.  相似文献   
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The mineralogical characterization and pyrolysis kinetics of raw oil shale from Moroccan Rif region and the corresponding bitumen-free material were investigated using various analytical techniques. The structural analysis results showed the siliceous character of mineral matrix and the presence of complex organic components in both oil shales studied. Non-isothermal pyrolysis kinetic measurements indicated that bitumen-free oil shale exhibits a single behavior pyrolysis in the oil-producing stage as compared to raw oil shale. The activation energies estimated by using isoconversional methods reveal that the pyrolysis reaction occurred by one-step kinetic process. The kinetic parameters, determined from a nonlinear fitting method using various kinetic models g(α) and iterative Kissinger–Akahira–Sunose energy calculations, reveal that the pyrolysis mechanism is well described by the nth order kinetics (Fn), with n = 1.071, for bitumen-free oil shale, and n = 1.550, for kerogen of raw oil shale. The mechanism of the whole pyrolysis process of raw oil shale seems not to be affected by the elimination of bitumen, but only some kinetic changes have been recorded in the reaction order mechanism. The process pyrolysis is represented by independent reactions and consequently considered as parallel processes. Besides, the thermodynamic functions of activated complexes (?S , ?H and ?G ) were also calculated and the pyrolysis is found as non-spontaneous process in agreement with the thermal analysis data.  相似文献   
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Processing of cocoa (Theobroma cacao L.) beans responsible for agricultural exports leads to large amounts of solid waste that were discarded, however, this one presents high contents of metabolites with biological activities. The major objective of this study was to valorise cocoa agroindustrial residue obtained by hydraulic pressing for extract rich in antioxidants. For it, the centesimal composition of residue was investigated, the green extraction was carried out from the residue after, the bioactive compounds, sugar contents and screaming by HPTLC were quantified for extract. The extract has a total polyphenol content of 229.64 mg/g and high antioxidant activity according to ABTS 225.0 μM/g. HTPLC analysis confirmed the presence in the extract, residue of terpenes, sesquiterpenes, flavonoids and antioxidant activity. These results, as a whole, suggest that the extract from the cocoa residue has interesting characteristics to alternative crops with potential industrial uses.  相似文献   
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