Nanoemulsions of Acai Oil: Physicochemical Characterization for the Topical Delivery of Antifungal Drugs

Nanoemulsion-based acai oil was obtained by the phase inversion method using two nonionic surfactants, Ceteareth-20 (Brij™ CS20) and polyoxyethylene-hydrogenated castor oil (Croduret™ 50), with the concentration of each surfactant varying from 7 to 10 %. The formulation with 10 % Brij CS20 presented the best values for droplet size, zeta potential, and polydispersity index (PDI). Ketoconazole was incorporated into this formulation, with an encapsulation efficiency of 98.31 % and equally good zeta potential, droplet size, and PDI, and spherical shape when observed by transmission electron microscopy. Overall, nanoemulsions of acai oil proved to be a good vehicle for imidazole antifungals such as ketoconazole.     

Biogenic amines assessment during different stages of the canning process of skipjack tuna (Katsuwonus pelamis)

The present research focused on the biogenic amines (BAs) formation in skipjack tuna (Katsuwonus pelamis) throughout the whole canning process. In agreement with its wide employment on this species, on‐board brine immersion freezing (BIF) was tested as post‐mortem processing. The study included fish samples corresponding to different stages of the canning process such as frozen, thawed, cooked and canned; after cooking, two kinds of tuna muscles were considered, that is, whole fillets (main product) and grated muscle (off‐product arising from small pieces). For the BAs (tryptamine, putrescine, cadaverine, histamine, spermidine and spermine) assessment, an HPLC‐DAD method was developed and validated in skipjack tuna samples, in agreement with different parameters such as suitability, linearity, limits of detection and quantification, precision, accuracy and robustness. Tuna submitted on‐board to BIF procedure provided low levels of spermine and spermidine (up to 27.6 mg kg^?1), while contents on the remaining BAs maintained below the limit of detection. Throughout the different stages of the canning process, skipjack tuna showed a low formation of most BAs; interestingly, histamine content was found below 10.6 mg kg^?1 level. The highest values were obtained for spermidine, these related to cooked grated tuna (from 22.6 to 66.7 mg kg^?1) and canned grated tuna (from 70.6 to 104.4 mg kg^?1). Values for pH assessment in all kinds of tuna samples corroborated the results obtained for BAs determination. BIF procedure proved to be an amenable post‐mortem processing to guarantee the quality of canned skipjack tuna.     

Effects of gastrointestinal digestion models in vitro on phenolic compounds and antioxidant activity of juçara (Euterpe edulis)

This study evaluated the effects of different gastrointestinal digestion models in vitro on the bioaccessibility of phenolics and antioxidant activity in juçara frozen pulp. In the sequence, method 3 was applied to juçara fruit in three different stages of maturation (vitrin – reddish fruits, mature – purple fruits, tuíra – deep purple fruits). In the method applied, the final pH adopted was 5.0, in order to avoid interference in the assay used to determine the antioxidant activity, and BHT was used to prevent excessive oxidation in the system. In this method, higher values for antioxidant activity were obtained (3574.95–3719.10 μmol L^?1 Trolox 100 g^?1 pulp) compared with the other two methods tested (1969.14–3034.74 μmol L^?1 Trolox 100 g^?1 pulp). In relation to juçara fruit, the mature stage was found to be ideal for processing, showing generally higher values of the bioaccessibility for phenolics and antioxidant activity compared to other maturation stages.     

A conceptual model for project management of exploration and production in the oil and gas industry: The case of a Brazilian company

The objective of this study was to obtain a better understanding of factors that influence Exploration and Production (E&P) project management success and corporate financial performance. The study follows structural equation modeling (SEM) methodology to achieve greater understanding of the intricate network of relationships between variables involved in E&P project management. A comprehensive theoretical framework was needed to formulate the conceptual basis of research. Observation of the real world and practical experiences were also important. To that end, we conducted a case study in a large Brazilian oil company. Field research was essential because of the lack of similar studies in the oil and gas sector. The model developed is a theoretical construct known as a structural and measurement model (set of latent variables, observed variables and hypotheses, depicted in a path diagram). This model contributes significantly to the company because it is a global representation of the main factors for improving E&P project management. However, the findings should be interpreted with caution because adjustment and validation of the theoretical model were not performed.     

Chemical composition and antioxidant activity of Gaylussacia brasiliensis (camarinha) grown in Brazil

This paper presents the centesimal and mineral composition, fatty acid profile of the lipidic fraction, phenolic and anthocyanin contents, and antioxidant activity of Gaylussacia brasiliensis fruit. The results indicated the following composition: moisture (81.30%), lipids (0.62%), proteins (0.56%), carbohydrates (10.74%), dietary fiber (6.53%), and ash (0.25%). The main elements comprising the mineral composition were K, Mg, Ca, and Fe. The fatty acid composition was characterized by a high content of polyunsaturated fatty acids (62.2%) and a high PUFA/SFA ratio (2.92). The G. brasiliensis fruit contained considerable amounts of phenolics (492.87 mgAG/100 g) and anthocyanins (240.43 mg/100 g), which contribute to its high antioxidant activity. This study highlights the potential of this fruit as an important source of both nutritional and bioactive compounds available in the native Brazilian flora.     

Quantitative determination of the phenolic antioxidants using voltammetric techniques

Synthetic antioxidants, such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ), show sensitivity to voltammetric waves. The waves of these antioxidants, however, are seriously overlapped and it is difficult to determine them simultaneously. The influence of different parameters (working electrode, supporting electrolyte, pH, voltammetric technique) was evaluated in a quantitative simultaneous determination of three antioxidants in alcoholic mixtures and real sample foods. Glassy carbon (GC) and platinum (Pt) working electrodes were investigated as mediators of oxireduction reactions. Two supporting electrolytes were investigated: Britton-Robinson 0.1 mol l⁻¹ buffer (pH 2.0) and HCl 0.1 mol l⁻¹ (pH 2.0) both with 2 g l⁻¹ (p/v) of methanol. In this paper, voltammetric conditions for the analysis of up to three-component mixtures of antioxidant present at levels: 2.0-100.0 mg l⁻¹ for BHA, 4.0-100.0 mg l⁻¹ for TBHQ and 2.0-20.0 mg l⁻¹ for BHT at GC in HCl 0.1 mol l⁻¹ and 8.0-120.0, 10.0-130.0 and 4.0-30.0 mg l⁻¹ for BHA, TBHQ and BHT, respectively, at Pt in the same supporting electrolyte. The results show that for real food samples, the parameters investigated were satisfactory for quantitative determination using square wave voltammetry (SWV) without chemometric approaches and without suffering overlapping problems.