DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR PALM OIL DETERMINATION IN MICROCAPSULES PRODUCED BY COMPLEX COACERVATION

The microencapsulation of palm oil may be a mechanism for protecting and promoting the controlled release of its bioactive compounds. To optimize the microencapsulation process, it is necessary to accurately quantify the palm oil present both external and internal to the microcapsules. In this study, we developed and validated a spectrophotometric method to determine the microencapsulation efficiency of palm oil by complex coacervation. We used gelatin and gum arabic (1:1) as wall material in a 5% concentration (w/v) and palm oil in the same concentration. The coacervates were obtained at pH 4.0 ± 0.01, decanted for 24 h, frozen (−40 ºC), and lyophilized for 72 h. Morphological analyzes were then performed. We standardized the extraction of the external palm oil through five successive washes with an organic solvent. We then explored the best method for rupturing the microcapsules. After successive extractions with hexane, we determined the amount of palm oil contained in the microcapsules using a spectrophotometer. The proposed method was shown to be of low cost, fast, and easy to implement. In addition, in the validation step, we confirmed the method to be safe and reliable, as it proved to be specific, accurate, precise, and robust.

DESENVOLVIMENTO DE EXPERIMENTO DIDÁTICO DE ELETROGRAVIMETRIA DE BAIXO CUSTO UTILIZANDO PRINCÍPIOS DA QUÍMICA VERDE

In this paper, we describe the development of low-cost teaching experiments of electrogravimetry for undergraduate students using principles of green chemistry. Copper was electrochemically deposited on brass under an electrical current density of 50 mA cm−2 from acidic solutions containing nitrate anions. Color changes at the brass electrode and of the solution were observed, indicating that the reduction of copper ions had occurred. The deposition efficiency values were between 92.8% and 93.8%, and the electrochemical efficiency values were between 85.6% and 86.5%. There was no significant contribution from parallel reactions. These experimental conditions facilitated the didactic exploration of gravimetric and electrochemical concepts. Following the principles of green chemistry, the experiments produced no toxic substances, all the materials could be recycled, and the energy consumption was the lowest. For this reason, this experiment was considered to be very interesting for didactical purposes.

Uses of natural zeolite in the removal of Pb2+ from contaminated water

In this paper, we carry out a study on the process of sorption of lead in polluted waters usingnatural zeolites, with the objective of analyzing their behavior in the purification of water.Experiments are carried out under static and dynamic conditions to determine the influence of other metal ions, such as: Ca (II), Mg (II), K (I) and Na (I), on this process. We demonstrate that the affinity of Pb (II) with regard to zeolite is higher than that of the ions mentioned above. It allows us to use this material in the capture of lead in residual waters. A lineal model of regression was obtained using a computer program called Eureka which relates the capacity of interchange of zeolite with respect to the concentration of the metal ions present in waters. We also studied the selectivity of zeolite in the process of sorption of Pb (II) compared with other heavy metals like Zn (II) and Cd (II).The results achieved in both cases increase the expectancy about the usage of zeolite as a low cost material for purifing waters.

Potentiometric determination of captopril in pharmaceutical formulations

A simple, precise, rapid and low-cost potentiometric method for captopril determination in pure form and in pharmaceutical preparations is proposed. Captopril present in tablets containing known quantity of drug was potentiometrically titrated in aqueous solution with NaOH using a glass pH electrode, coupled to an autotitrator. No interferences were observed in the presence of common components of the tablets as lactose, microcrystalline cellulose, croscarmellose sodium, starch and magnesium stearate. The analytical results obtained by applying the proposed method compared very favorably with those obtained by the United States Pharmacopoeia Standard procedure. Recovery of captopril from various tablet dosage formulations range from 98.0 to 102.0%.

Spectrophotometric determination of diclofenac in pharmaceutical preparations assisted by microwave oven

In this work, an effective and low-cost method for the determination of sodium or potassium diclofenac is proposed in its pure form and in their pharmaceutical preparations. The method is based on the reaction between diclofenac and tetrachloro-p-benzoquinone (p-chloranil), in methanol medium. This reaction was accelerated by irradiating of reactional mixture with microwave energy (1100 W) during 27 seconds, producing a charge transfer complex with a maximum absorption at 535 nm. The optimal reaction conditions values such as reagent concentration, heating time and stability of the reaction product were determined. Beer's law is obeyed in a concentration range from of 1.25x10-4 to 2.00x10-3 mol l-1 with a correlation coefficient of 0.9993 and molar absorptivity of 0.49 x10³ l mol-1 cm-1. The limit of detection (LOD) was 1.35x10-5 mol l-1 and the limit of quantification (LOQ) was 4.49x10-5 mol l-1. In the presence of the common excipients, such as glucose, lactose, talc, starch, magnesium stearate, sodium sulphite, titanium dioxide, polyethyleneglycol, polyvinylpirrolidone, mannitol and benzilic alcohol no interferences were observed. The analytical results obtained by applying the proposed method compare very favorably with those given by the United States Pharmacopeia standard procedure. Recoveries of diclofenac from various pharmaceutical preparations were within 95.9% to 103.3%, with standard deviations ranging from 0.2% to 1.8%.

Spectrophotometric determination of methyldopa in pharmaceutical formulations

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer's Law is obeyed in a concentration range of 50 - 200 µg ml-1 methyldopa with an excellent correlation coefficient (r = 0.9999). No interference was observed from common excipients in formulations. The results show a simple, accurate, fast and readily applied method to the determination of methyldopa in pharmaceutical products. The analytical results obtained for these products by the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at 95% confidence level.

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis

The combination of two low-cost classical procedures based on titrimetric techniques is presented for the determination of pyridoxine hydrochloride in pharmaceuticals samples. Initially some experiments were carried out aiming to determine both pKa1 and pKa2 values, being those compared to values of literature and theoretical procedures. Commercial samples containing pyridoxine hydrochloride were electrochemically analysed by exploiting their acid-base and precipitation reactions. Potentiometric titrations accomplished the reaction between the ionizable hydrogens present in pyridoxine hydrochloride, being NaOH used as titrant; while the conductimetric method was based on the chemical precipitation between the chloride of pyridoxine hydrochloride molecule and Ag+ ions from de silver nitrate, changing the conductivity of the solution. Both methods were applied to the same commercial samples leading to concordant results when compared by statistical tests (95 and 98% confidence levels). Recoveries ranging from 99.0 to 108.1% were observed, showing no significant interference on the results.

Management of crotalaria and pigeon pea for control of yam nematode diseases

Management of plant-parasitic nematodes with the use of nematicides has not been recommended for small farmers that grow yam in the Northeastern region of Brazil, due to its high cost and residue toxicity. The use of plants with antagonistic effect to nematodes and green manure which improves soil chemical, physical and biological characteristics can be a viable and low cost alternative to control parasitic nematodes. This work aimed to evaluate the effect of crotalaria (Crotalaria juncea) and pigeon pea (Cajanus cajan) plants on the control of yam nematodes. Three experiments were carried out. The first was conducted under in vitro conditions to evaluate the nematostatic and nematicide effect of extracts from fresh and dry matter of the above ground parts of crotalaria, pigeon pea, and the combination of both. The second experiment was carried out under greenhouse conditions to evaluate the effect of soil amendment with crotalaria, pigeon pea, and the combination of both in the infectivity of Scutellonema bradys, using tomato plants as the host plant. The third experiment was conducted under field conditions to evaluate the effect of crotalaria, pigeon pea, and the combination of both, cultivated between yam planting rows and incorporated to soil surface, on yam nematodes. The aqueous extract obtained form fresh matter of crotalaria had a nematicide effect of 100% for S. bradys. Extracts from dry matter of both crotalaria and pigeon pea did not have any nematicide effect, but had a nematostatic effect. Incorporation of crotalaria to soil inhibited infectivity of S. bradys in tomato seedlings. These results showed that planting crotalaria alone or in combination with pigeon pea, between the yam planting rows, is an efficient method for controlling S. bradys and Rotylenchulus reniformis associated with yams. Crotalaria can be used for controlling these plant-parasitic nematodes in soil.

Genetic transformation of Eucalyptus camaldulensis by agrobalistic method

Eucalyptus stands in the setting of worldwide forestry due to its adaptability, rapid growth, production of high-quality and low cost of wood pulp fibers. The eucalyptus convetional breeding is impaired mainlly by the long life cycle making the genetic transformation systems an important tool for this purpose. However, this system requires in vitro eficient protocols for plant induction, regeneration and seletion, that allow to obtain transgenic plants from the transformed cell groups. The aim of this work was to evaluate the callus formation and to optimize the leaves and callus genetic transformation protocol by using the Agrobacterium tumefaciens system. Concerning callus formation, two different culture media were evaluated: MS medium supplemented with auxin, cytokinin (M1) and the MS medium with reduced nitrogen concentration and supplemented with auxin, cytokinin coconut water (M2). To establish the leave genetic transformation, those were exposed to agrobiolistics technique (gene gun), to tissue injury, and A. tumesfasciens EHA 105 contening the vetor pCambia 3301 (35S::GUS::NOS), for gene transference and to establish the callus transformation thoses were exposed only to A. tumefasciens. For both experiments, the influence of different infection periods was evaluated. The M2 medium provided the best values for callus sizea and fresh and dry weight. The leaves genetic transformation using the agrobiolistics technique was effective, the gus gene transient expression could be observed. No significant differences were obtained in the infection periods (4, 6 and 8 minutes). The callus genetic transformation with A. tumefaciens also promotend the gus gene transient expression on the callus co-cultiveted for 15 e 30 minutes. The transformed callus was transfered to a regeneration and selection medium and transformed plants were obtained.

Using aster multispectral imagery for mapping woody invasive species in pico da vara natural reserve (Azores Islands, Portugal)

This paper aims to assess the effectiveness of ASTER imagery to support the mapping of Pittosporum undulatum, an invasive woody species, in Pico da Vara Natural Reserve (S. Miguel Island, Archipelago of the Azores, Portugal). This assessment was done by applying K-Nearest Neighbor (KNN), Support Vector Machine (SVM) and Maximum Likelihood (MLC) pixel-based supervised classifications to 4 different geographic and remote sensing datasets constituted by the Visible, Near-Infrared (VNIR) and Short Wave Infrared (SWIR) of the ASTER sensor and by digital cartography associated to orography (altitude and "distance to water streams") of which the spatial distribution of Pittosporum undulatum directly depends. Overall, most performed classifications showed a strong agreement and high accuracy. At targeted species level, the two higher classification accuracies were obtained when applying MLC and KNN to the VNIR bands coupled with auxiliary geographic information use. Results improved significantly by including ecology and occurrence information of species (altitude and distance to water streams) in the classification scheme. These results show that the use of ASTER sensor VNIR spectral bands, when coupled to relevant ancillary GIS data, can constitute an effective and low cost approach for the evaluation and continuous assessment of Pittosporum undulatum woodland propagation and distribution within Protected Areas of the Azores Islands.

BIOMASS SUPPLY CHAIN ANALYSIS WITH DENSIFIED WASTE

ABSTRACT The possibility to vary the energy matrix, thus reducing the dependency on fossil fuels, has amplified the acceptance of biomass as an alternative fuel. Despite being a cheap and renewable option and the fact that Brazil is a major producer of waste from agriculture and forestry activities, the use of these materials has barriers due to its low density and low energetic efficiency, which can raise the costs of its utilization. Biomass densification has drawn attention due to its advantage in comparison to in natura biomass due to its better physical and combustion characteristics. The objective of this paper is to evaluate the impact of biomass densification in distribution and transport costs. To reach this objective, a mathematical model was used to represent decisions at a supply chain that coordinates the purchase and sale of forestry and wood waste. The model can evaluate the options to deliver biomass through the supply chain combining demand meeting and low cost. Results point to the possibility of an economy of 60% in transport cost and a reduction of 63% in the required quantity of trucks when densified waste is used. However, costs related to the densifying process lead to an increase of total supply costs of at least 37,8% in comparison to in natura waste. Summing up, the viability of biomass briquettes industry requires a cheaper densification process.

Swine effluent treatment using anaerobic digestion at different loading rates

The industrial swine production is characterized by generation of significant effluent amounts that require treatment. The most adopted practices by Brazilian swine farmers have been wastewater storage in lagoons and its subsequent use as a biofertilizer. Nutrient accumulation in soil and water creates the need for an effective management of these residues. The anaerobic digestion process is an important alternative and low-cost treatment for organic matter reduction. However, its efficiency is limited by the digester capacity of solid degradation, especially at low hydraulic retention times. Thus, the present study aimed to verify the behavior of an upflow anaerobic digester by increasing the organic loading rate. This was accomplished in three stages using, as a parameter, volatile solids at 0.5; 1.0 and 1.5 kgVS m-3 d-1, respectively. This digester model proved to be quite robust and effective in swine manure treatment, achieving high efficiency of volatile solid removal at all stages of the study (stage 1: 61.38%; stage 2: 55.18%; and stage 3: 43.18%). Biogas production was directly related to the increasing organic load, reaching 0.14, 0.85, and 0.86 Nm³ kgVS-1add., respectively, with no significant difference (p<0.05) of biogas methane concentration among the studied stages (73.7, 75.0, and 77.9%).

Portable flow board for storage of fruits and vegetables in mini-chambers with controlled atmosphere

ABSTRACT A portable flow board system was developed in the present study with the aim to facilitate lab-scale experiments of controlled atmosphere (CA) with fruits and vegetables. This sturdy flow board combines ease fabrication, low cost and gas economy. Its functionality is provided by manifolds and gas mixers. Each gaseous component is supplied by a gas cylinder through a differential valve of adjusted pressure control, generally at 6 kPa, and forced through 13 standardized restrictors coupled to each manifold output. Controlled atmospheres are then formed with one, two or three gases in 13 gas mixers affixed to the flow board base, which are further conducted through flexible tubes to storage mini-chambers that can also be used to study metabolic consumption and production of gaseous components. The restrictors used in the flow gaseous components were manufactured from microhematocrit test-type capillary glass tubes following the hot forming method under continuous air flow. The portable flow board showed to be low cost and simple post-harvest equipment that allows preparing controlled atmospheres in open systems with stable composition and flow, in a manner similar to traditional flow boards with control of gas escape by barostats.

IDENTIFICATION OF SUITABLE AREAS FOR IRRIGATED RICE CROPPING USING MODIS IMAGES AND HAND MODEL

ABSTRACT One of the most relevant activities of Brazilian economy is agriculture. Among the main crops in Brazil, rice is one of high relevance. The state of Rio Grande do Sul, in Southern Brazil, is responsible for 68.7% of domestic production (IBGE, 2013). The goal of this study was to develop a low-cost methodology with a regional scope to identify suitable areas for irrigated rice cropping in this state, using spectro-temporal behavior of vegetation index by means of MODIS images and HAND model. The rice-cropped area of this study was the southern half of the State. Using the HAND model, flood areas were mapped to identify irrigated rice cultivation. We used multi-temporal images of vegetation index from MODIS sensor, covering the period from August 2001 to May 2012. To assess the results, we used data collected in the fields and cropped area information from IBGE. The results showed that the proposed methodology was satisfactory, with Kappa 0.92 and global accuracy of 98.18%. As result, MODIS sensor data and flood areas delineation by means of HAND model generated the estimate irrigated rice area for the area of study.

Nova técnica de alimentação enteral em fístulas esôfago-jejunais

BACKGROUND: A new procedure for the treatment of esophageal fistula, mainly associated to the ebb esophagojejunal in patients submitted to the total gastrectomy and reconstruction with loop jejunal Rouxen-Y anastomosis is present. METHODS: The method is based in the use of "probe standard enteral prolongated with drain to laminate adapted in extremity", which results in advanced positioning inside the jejunum, making the administration of enteral nutrition possible and impeding ebb esophagojejunal. RESULTS: The authors discuss the theoretical advantages of the procedure and they suggest that the treatment of esofagic fistula with probe prolonged enteral would be suitable in the treatment of the fistula esophagojejunal by preventing the ebb esophagojejunal, which would result in smaller period of duration of the fistula esophagojejunal and it would prevent the high mortality rate. CONCLUSIONS: Preliminary studies demonstrated that this is a technically easy, low cost procedure through the endoscopic use. A prospective evaluation for morbility and mortality related to the method is needed.