Caroline E. Mendes

Atividade antioxidante de pimentas do gênero Capsicum

The antioxidant activity was evaluated by the β-Carotene/Linoleic Acid System, DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical assay, to the crude extract (EB) and fractions hexanic (FH), chloroformic (FC), and ethyl acetate (FA) of malagueta peppers (C. frutescens), cambuci (C. baccatum var. pendulum), cumari (C. baccatum var praetermissum), and pepper magali (C. annuum var. annuum). The concentration of total phenolics and capsacinoids present in the peppers was also determined. The results showed that the FC and the FA peppers showed higher concentrations of total phenolics and capsacinoids, and that the cumari pepper was the species with higher concentrations of these compounds. The best antioxidant activity according to the β-Carotene/Linoleico Acid System were obtained for the EB and the FA cambuci pepper, followed by the EB malagueta pepper. According to the DPPH method, the FC and FA showed lower values of EC50, and the cumari and cambuci peppers were the most effective. The results show that cumari, cambuci, and malagueta peppers can be used as natural antioxidant agents in food.

Clastogenic and anticlastogenic effect of the essential oil from Casearia sylvestris Swart

Abstract The essential oil composition obtained from the leaves of Casearia sylvestris has been investigated by GC and GC/MS. Thirty-seven compounds were identified in the oil. The major constituents of which were β-caryophyllene (27.5%) and bicyclogermacrene (24.2%). The clastogenic and anticlastogenic effect of the oil was tested by chromosome aberration in cells of tissue hepatoma of Rattus novergicus. The three different concentrations of C. sylvestris oil showed clastogenic effects. However, in the tests of anticlastogenicity, the same three concentrations showed protective activity when associated with ethyl methanesulfonate (EMS).

Global performance parameters for different pneumatic bioreactors operating with water and glycerol solution: experimental data and CFD simulation.

Global variables play a key role in evaluation of the performance of pneumatic bioreactors and provide criteria to assist in system selection and design. The purpose of this work was to use experimental data and computational fluid dynamics (CFD) simulations to determine the global performance parameters gas holdup (

Chemical composition and multivariate analysis of the volatile oil of Dalbergia frutescens (Vell.) Britton (Fabaceae)

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Oxygen transfer in different pneumatic bioreactors containing viscous Newtonian fluids

α¯G) and volumetric oxygen transfer coefficient (kLa), and conduct an analysis of liquid circulation velocity, for three different geometries of pneumatic bioreactors: bubble column, concentric-tube airlift, and split tube airlift. All the systems had 5 L working volumes and two Newtonian fluids of different viscosities were used in the experiments: distilled water and 10 cP glycerol solution. Considering the high oxygen demand in certain types of aerobic fermentations, the assays were carried out at high flow rates. In the present study, the performances of three pneumatic bioreactors with different geometries and operating with two different Newtonian fluids were compared. A new CFD modeling procedure was implemented, and the simulation results were compared with the experimental data. The findings indicated that the concentric-tube airlift design was the best choice in terms of both gas holdup and volumetric oxygen transfer coefficient. The CFD results for gas holdup were consistent with the experimental data, and indicated that kLa was strongly influenced by bubble diameter and shape.

Hydrodynamics of Newtonian and non-Newtonian liquids in internal-loop airlift reactors

The blackberry drying process was studied using an experimental design with three factors, namely: sample weight (6 to 135 g), drying temperature (30 to 80 °C) and time (16 to 24 h). All samples were grounded and dried accordingly, in a convection oven with air circulation. Moisture and phenolic compounds concentration were chosen as response variables. Results showed small losses of bioactive compounds for the 80 g sample dried at 55 °C for 16 hours. Furthermore, the blackberry flour meets the Brazilian standards to moisture (maximum 15%) and can be classified as a product of high fiber content (24.33±2.88 g/100 g of flour). Bioactive compounds in the flour were quantified using spectrophotometric analysis: total phenolic of 344.94 mg GAE/100 g; total flavonoids of 182.82 Ce mg/100 g; total anthocyanins of 77.93 mg/100 g; monomeric anthocyanins of 82.41 CYD-3-G/100 g; total carotenoids of 0.322 mg/100 g and activity anti-DPPH EC50 21.2 μg/mL. These results show that blackberry flour is rich in bioactive compounds, adding nutritional value to foods and products made with this flour.

Prediction of Oxygen Transfer and Gas Hold-Up in Pneumatic Bioreactors Containing Viscous Newtonian Fluids

The chemical composition of the volatile oil from the leaves of three specimens of D. frutescens, collected over a period of one year, was determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). These essential oils were characterized by the presence of norisoprenoids (β-damascenone, β-ionone, and α-ionone), as well as sesquiterpenes. Multivariate analysis showed that the compounds β-damascenone and β-ionone exerted the greatest influence on spatial and temporal differences in the composition of the oils. Samples obtained from specimens located in the same city showed similar chemical compositions.

ESTIMATIVA DE PARÂMETROS GLOBAIS DE DESEMPENHO EM BIORREATORES PNEUMÁTICOS DE CIRCULAÇÃO INTERNA OPERANDO COM FLUIDO NÃO-NEWTONIANO POR FLUIDODINÂMICA COMPUTACIONAL

The volatile oils of Dalbergia frutescens were obtained by hydrodistillation on a Clevenger-modified apparatus for every month of one year and assessed on GC/MS and GC/FID detectors for qualitative and quantitative analyses. The influence on content of volatile oils was directly proportional to the environmental variables, temperature and cloudiness, and inversely proportional to precipitation. Among the volatile compounds detected, linalool, β-damascenone, α-ionone, geranyl acetone and β-ionone were the main components, of which β-damascenone and β-ionone were found at the highest concentrations.