André Jablonski

Characterisation and stability evaluation of bixin nanocapsules

The aim of this study was to produce bixin nanocapsules by the interfacial deposition of preformed poly-ε-caprolactone (PCL). PCL (250 mg), capric/caprylic triglyceride (400 μL), sorbitan monostearate (95 mg) and bixin were dissolved in a mixture of acetone (60 mL) and ethanol (7.5 mL) under stirring (40 °C). This organic solution was added to the aqueous solution (130 mL) containing Tween 80 (195 mg). The size distributions in the formulations with bixin concentration from 11 to 100 μg/mL were evaluated periodically during 3 weeks of storage at ambient temperature. The optimal formulation (bixin concentration of 16.92±0.16 μg/mL) was characterised in terms of particle size distribution, zeta potential, bixin content and encapsulation efficiency, and showed a volume-weighted mean diameter (D4,3) of 195±27 nm, around 100% of encapsulation efficiency and the nanocapsules were considered physically stable during 119 days of storage at ambient temperature.

Effect of cooking on the concentration of bioactive compounds in broccoli (Brassica oleracea var. Avenger) and cauliflower (Brassica oleracea var. Alphina F1) grown in an organic system.

Brassica vegetables have been shown to have antioxidant capacities due to the presence of carotenoids, flavonoids and vitamins. This study evaluates the influence of different processing conditions (boiling, steaming, microwaving and sous vide) on the stability of flavonoids, carotenoids and vitamin A in broccoli and cauliflower inflorescences grown in an organic system. Results indicated that sous vide processing resulted in greater antioxidant capacity and that all processes contributed in some way to an increased content of antioxidant compounds in both cauliflower and broccoli.

Patulin in food: state-of-the-art and analytical trends

Patulin is a mycotoxin produced by several fungal species of the genera Penicillium and Aspergillus, found on several fruit species and, remarkably, in apples and apple products. Patulin has a broad spectrum of toxicity, including carcinogenicity and teratogenicity in animals. Due to the stability of the molecule, considerable amounts of patulin still remain in apple products after processing. This paper reviews different analytical methods for patulin determination and methods to reduce levels of patulin in apple products as well.

Desulfurization kinetics of coal combustion gases

Desulfurization of the gases from coal combustion was studied, using limestone (marble) as the sorbent in a fluidized-bed reactor. The kinetic parameter, k, was measured by analyzing the reduction in SO2 emissions in relation to time when a batch of limestone was introduced directly into the combustor chamber. The influence of sorbent composition and particle size was also studied. The CaO content in the limestone was more important than the MgO content. Sorbent particle size showed a strong influence on the reaction time and efficiency of desulfurization. The results of this work prove that marble type is very important in the choice of sorbent for a desulfurization process. A magnesian limestone showed a better performance than a dolomite. Therefore, the magnesian limestone is more efficient for a shorter particle residence time, which is characteristic of the bubbling fluidized bed.

Determinação do 5-hidroximetilfurfural em méis utilizando cromatografia eletrocinética capilar micelar

In this work, the occurrence of HMF (5-hydroxymethylfurfural) in honey marketed in Porto Alegre – RS was investigated using Micellar Electrokinetic Capillary Chromatography. The HMF, which is the product of the fructose condensation, is an indicator of honey quality and conservation. Eleven types of honey commercialized in Porto Alegre were analyzed, and all of them contained HMF in a range from 0.191 to 6.206 mg.kg –1 . In order to quantify the HMF present in the samples, the technique of standard addition was employed. The recovery was 98% and the detection limit was 0.025 mg.kg –1 . The allowed limit of HMF in honey, according to the Brazilian Legislation, is 60 mg.kg –1

Desenvolvimento das raízes do azevém cultivado em solução nutritiva completa, adicionada de substâncias húmicas, sob condições de casa de vegetação

This work was carried out under greenhouse conditions, in 1997, at Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul (UFRGS). A split plot randomized complete block experimental design was used, with six replications, to evaluate root lengths, average radius, roots surface and dry matter of roots with the objective to evaluate the effect of humic compounds addition in the development of ryegrass roots. Ryegrass forage was grown in pots with irrigated sand with four levels of humic compounds added to a complete nutritive solution with four-doses of humic compounds (0, 10, 20 and 30-mg/liter). The humic compounds were extracted from the charcoals of the Capane (Palermo CE-4,200 and Palermo CE-4,700), Leao (Leao CE-5,200) and Candiota (Candiota superior layer, Candiota inferior layer, CE-3,300 and Candiota CE-4,700) mines. For all variables, the statistical analyses showed significance for the interaction dose x raw material effects. Results demonstrated that humic compounds promoted roots development, increasing: a) roots length at 100,87%; b) roots weight at 49,23% and c) 68% of the roots surface. The humic compounds influence ryegrass roots development and that these substances from different raw materials distinctly act on the parameters of the four variables analyzed.

Hydroethanolic extracts from different genotypes of açaí (Euterpe oleracea) presented antioxidant potential and protected human neuron-like cells (SH-SY5Y)

Fruit breeding programs have resulted in bioactive compounds increase and health effects. Thus, this study aimed to evaluate the antioxidant activity and neuroprotective effects of the hydroethanolic extracts from six açaí (Euterpe oleracea) genotypes using ABTS, deoxyribose, and glutathione oxidation assays, as well as, SH-SY5Y cells insulted with H2O2. L22P13 genotype showed the highest total content of anthocyanins, while L06P13 showed a high content of total carotenoids. However, the genotypes showed no difference in the antioxidant activity by ABTS and deoxyribose assays. The hydroethanolic extracts from different genotypes of açaí showed a protective effect (13-62%) on SH-SY5Y cells insulted by H2O2 at a concentration of 50μg/mL by DCFH-DA assay. Except L04P16, no genotypes showed cytotoxicity in the SRB assay. These results indicate that açaí genotypes have antioxidant effect against reactive species generated in SH-SY5Y cells, suggesting a neuroprotective effect of the hydroethanolic extracts from these fruits.

Estudo das partículas totais em suspensão e metais associados em áreas urbanas

This work aims at the study of the air quality determination regarding the total suspended particles (TSP) and the associated metals in the counties of Charqueadas and Sapucaia do Sul at the state of Rio Grande do Sul. The TSP samples were collected using high volume samplers and the analysis of the metallic elements was accomplished through ICP-AES. The results revealed that the TSP concentrations, found in the two studied regions, have exceded the current air quality patterns established by the Brazilian Legislation. They also revealed high levels of several of the elements being attributed to the presence of anthropogenic sources. The correlation between meteorological data (speed and wind direction) and TSP concentrations were significant and revealed strong influence in particle dispersion.

The behavior of heavy metals in the process of desulfurization of Brazilian coal combustion gases by the addition of limestone

The concentrations of heavy metals in two kinds of Brazilian coals at 100° C (acid digestion) and at 850° C were studied (ashes the obtained in muffle furnace with and without addition of limestone). Data were analyzed by flame atomic absorption, using the air acetylene flame. For Pb, Zn, Ni, Mn and Cu the metal concentration obtained the acid digestion were higher than metal concentration were obtained in tests in the muffle furnace. This behavior observed in the muffle furnace occurs because these metals are fixed in stable sulfated compounds in the ashes, which are difficult to dissociate at flame temperature, and also due to the volatile character of the metals, mainly Pb and Zn. There was a constant concentration in the ashes in of Cr the acid digestion and muffle furnace tests. Results from tests using an XRD apparatus indicated, he formation of sulfated compounds in the ashes for both. coals. The analysis using microprobe electronic showed retention of metals like Ni, Mn, Cu, Fe, Ti and Ca. For both coals, the low mobility of most of the metals studied occured due to the alkaline pH of sulfated ashes. These metals in the ash from coal combustion in fluidized bed reactor were also studied and showed similar results, enabling a scale-up to pilot scale.

STABILITY-INDICATING CZE METHOD AND STRESS DEGRADATION STUDIES OF NITAZOXANIDE

A new, simple, and effective stability-indicating CZE method was developed and validated for the determination of nitazoxanide in pharmaceutical formulations, using nimesulide as an internal standard. The optimum separation was carried out on a fused silica capillary (48.5 cm × 75 μm i.d., effective length 40 cm) maintained at 25°C, and a running electrolyte containing sodium acetate buffer (pH 5.2; 30 mM)-acetonitrile (80:20, v/v). The injections of the samples were performed using the pressure mode at 50 mbar for 5 s, with detection at 360 nm using a photo-diode array detector. The method was suitably validated for specificity, linearity, precision, accuracy, limit of detection and quantitation, and robustness. The high sensitivity of the method was proven with the limit of detection (0.05 μg mL−1) and quantitation (0.2 μg mL−1). The stability-indicating capability of the method was proven using stress conditions (acid and basic hydrolysis, oxidation, and photolysis). The proposed method was successfully applied for the determination of nitazoxanide in coated tablets and oral suspension powder.