1000 resultados para TOTAL ACIDITY


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Tomatoes are one of the most important vegetable crops grown in Brazil and are among the crops that have one of the highest post-harvest losses indexes in the country. The present work aimed at evaluating impact damage observed in packing lines of fresh tomatoes as well as to determine, under laboratory conditions, quality alterations of tomato fruits submitted to impact damage in different surface types. Critical points evaluation was accomplished using an instrumented sphere. Critical transference points found showed variations in acceleration levels from 30 to 129 G (m s-2). Tests carried out under laboratory conditions showed that padded surfaces reduced up to 31% impact damage. Incidence of severe internal physical damage was evaluated by a subjective scale and increased by 79% on hard surfaces for the highest fall drop. On the other hand, it was observed an effective reduction in physical damage on fruits when padded surfaces were used. When a 10-cm drop was performed, the maximum reduction measured was 10% for hard surfaces and 5% for previously padded surfaces. For quality parameters, it was observed for high drops on hard surfaces, highest values for weight loss, total acidity, lower values for vitamin C and Soluble Solids.

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Multi-pumping flow systems exploit pulsed flows delivered by Solenoid pumps. Their improved performance rely on the enhanced radial mass transport inherent to the pulsed flow, which is a consequence of the establishment of vortices thus a tendency towards turbulent mixing. This paper presents several evidences of turbulent mixing in relation to pulsed flows. such as recorded peak shape, establishment of fluidized beds, exploitation of flow reversal, implementation of relatively slow chemical reactions and/or heating of the reaction medium. In addition, Reynolds number associated with the GO period of a pulsed flow is estimated and photographic images of dispersing samples flowing under laminar regime and pulsed flow conditions are presented. (C) 2009 Elsevier B.V. All rights reserved.

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Since hog raising concentrates a huge amount of swine manure in small areas, it is considered by the environmental government organizations to be one of the most potentially pollutant activities. Therefore the main objective of this research was to evaluate by operational criteria and removal efficiency, the performance of a Anaerobic Baffled Reactor (ABR), working as a biological pre-treatment of swine culture effluents. The physical-chemical analyses carried out were: total COD, BOD(5), total solids (TS), fix (TFS) and volatiles (TVS), temperature, pH, total Kjeldahl nitrogen, phosphorus, total acidity and alkalinity. The ABR unit worked with an average efficiency of 65.2 and 76.2%, respectively, concerning total COD and BOD(5), with a hydraulic retention time (HRT) about 15 hours. The results for volumetric organic loading rate (VOLR), organic loading rate (OLR) and hydraulic loading rate (HLR) were: 4.46 kg BOD m(-3) day(-1); 1.81 kg BOD(5) kg TVS(-1) day(-1) and 1.57 m(3) m(-3) day(-1), respectively. The average efficiency of the whole treatment system for total COD and BOD(5) removal were 66.5 and 77.8%, showing an adequate performance in removing die organic matter from swine wastewater.

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Aim of the study: In a previous study, our group described the gastric protective effect of the hydroalcoholic extract of Brazilian green propolis. The main compounds found in Brazilian green propolis include phenolic acids, such as: caffeic, ferulic, p-coumaric and cinnamic acids. This study was therefore carried out to evaluate the antiulcerogenic property of the main phenolic acids found in Brazilian Green Propolis. Material and methods: The anti-ulcer assays were performed using the following protocols: nonsteroidal-antinflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, and stress-induced ulcer. The effects of the phenolic acids on gastric content volume, pH and total acidity, using the pylorus ligated model, were also evaluated. Results: It was observed that treatment using doses of 50 and 250 mg/kg of caffeic, ferulic, p-coumaric and cinnamic acids and positive controls (omeprazol or cimetidine) significantly diminished the lesion index, the total area of the lesion and the percentage of lesion in comparison with the negative control groups. In addition, the percentage of ulcer inhibition was significantly higher in the groups treated with the different phenolic acids, cimetidine or omeprazol, in all the protocols used, compared with the negative control groups. In the model to determine gastric secretion, using ligated pylorus, treatment with phenolic acids and cimetidine reduced the volume of gastricjuice and total acidity and significantly increased the gastric pH (p < 0.05), compared with the control group, with the exception of the group treated with 50 mg/kg of p-coumaric acid, in which no significant difference was observed, compared with the control. In relation to the acute toxicity, none sign of toxicity was observed when phenolic acids, used in this study, were administered for rats in dose of 2000 mg/kg. Conclusions: In conclusion, the results of this study show that caffeic, ferulic, p-coumaric and cinnamic acids display antiulcer activity. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, commonly known as `Alecrim-do-campo` is widely used in folk medicine to treat inflammation, hepatic disorders and stomach ulcers, and it is the most important botanical source of Southeastern Brazilian propolis, known as green propolis. Its essential oil is composed of non-oxygenated and oxygenated terpenes. In this work, the effects of the essential oil obtained from the aerial parts of R dracunculifolia on gastric ulcers were evaluated. The antiulcer assays were undertaken using the following protocols in rats: nonsteroidal antiinflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, stress-induced ulcer, and determination of gastric secretion using ligated pylorus. The treatment in the doses of 50, 250 and 500 mg/kg of R dracunculifolia essential oil significantly diminished the lesion index, the total lesion area and the percentage of lesions in comparison with both positive and negative control groups. With regard to the model of gastric secretion a reduction of gastric juice volume and total acidity was observed, as well as an increase in the gastric pH. No sign of toxicity was observed in the acute toxicity study. Considering the results, it is suggested that the essential oil of B. dracunculifolia could probably be a good therapeutic agent for the development of new phytotherapeutic medicine for the treatment of gastric ulcer. Copyright (C) 2009 John Wiley & Sons, Ltd.

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Understanding the genetic variability of a species is crucial for the progress of a genetic breeding program and requires characterization and evaluation of germplasm. This study aimed to characterize and evaluate 101 tomato subsamples of the Salad group (fresh market) and two commercial controls, one of the Salad group (cv. Fanny) and another of the Santa Cruz group (cv. Santa Clara). Four experiments were conducted in a randomized block design with three replications and five plants per plot. The joint analysis of variance was performed and characteristics with significant complex interaction between control and experiment were excluded. Subsequently, the multicollinearity diagnostic test was carried out and characteristics that contributed to severe multicollinearity were excluded. The relative importance of each characteristics for genetic divergence was calculated by the Singh's method (Singh, 1981), and the less important ones were excluded according to Garcia (1998). Results showed large genetic divergence among the subsamples for morphological, agronomic and organoleptic characteristics, indicating potential for genetic improvement. The characteristics total soluble solids, mean number of good fruits per plant, endocarp thickness, mean mass of marketable fruit per plant, total acidity, mean number of unmarketable fruit per plant, internode diameter, internode length, main stem thickness and leaf width contributed little to the genetic divergence between the subsamples and may be excluded in future studies.

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Urea is the most consumed nitrogen fertilizer in the world. However, its agronomic and economic efficiency is reduced by the volatilization of NH3, which can reach 78 % of the applied nitrogen. The coating of urea granules with acidic compounds obtained by charcoal oxidation has the potential to reduce the volatilization, due to the acidic character, the high buffering capacity and CEC. This work aimed to evaluate the effect of HNO3-oxidized carbon on the control of NH3 volatilization. These compounds were obtained by oxidation of Eucalyptus grandis charcoal, produced at charring temperatures of 350 and 450 ºC, with 4.5 mol L-1 HNO3. The charcoal was oxidized by solubilization in acidic or alkaline medium, similar to the procedure of soil organic matter fractionation (CHox350 and CHox450). CHox was characterized by C, H, O, N contents and their respective atomic relations, by the ratio E4 (absorbance 465 nm) by E6 (absorbance 665 nm), and by active acidity and total acidity (CEC). The inhibitory effect of CHox on the urease activity of Canavalia ensiformis was assessed in vitro. The NH3 volatilization from urea was evaluated with and without coating of oxidized charcoal (U-CHox350 or U-CHox450) in a closed system with continuous air flow. The pH of both CHox was near 2.0, but the total acidity of CHox350 was higher, 72 % of which was attributed to carboxylic groups. The variation in the ionization constants of CHox350 was also greater. The low E4/E6 ratios characterize the high stability of the compounds in CHox. CHox did not inhibit the urease activity in vitro, although the maximum volatilization peak from U-CHox450 and U-CHox350 occurred 24 h after that observed for uncoated urea. The lowest volatilization rate was observed for U-CHox350 as well as a 43 % lower total amount of NH3 volatilized than from uncoated urea.

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In the present work, the physical and chemical characteristics in three stages of maturation of sapota (Manilkara zapota L.P. Royen) fruit were studied as well as its post-harvest behavior during storage at ambient and refrigerated conditions. With the advance of maturation, the concentration of the reducing sugars increased while the total acidity and tannin contents decreased. The fruits which did not have their pedicel removed during the post-harvest presented the storage time superior when compared with the fruits having their pedicels removed. The fruits stored under refrigeration had higher weight retention as compared to the fruits stored under ambient conditions.

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This work aims determinate the evaluation of the quality of 'Nanicão' banana, submitted to two conditions of storage temperature and three different kinds of package, using the technique of the Analysis of Principal Components (ACP), as a basis for an Analysis of Variance. The fruits used were 'Nanicão' bananas, at ripening degree 3, that is, more green than yellow. The packages tested were: "Torito" wood boxes, load capacity: 18 kg; "½ box" wood boxes, load capacity: 13 kg; and cardboard boxes, load capacity: 18 kg. The temperatures assessed were: room temperature (control); and (13±1ºC), with humidity controlled to 90±2,5%. Fruits were discarded when a sensory analysis determined they had become unfit for consumption. Peel coloration, percentages of imperfection, fresh mass, total acidity, pH, total soluble solids and percentages of sucrose were assessed. A completely randomized design with a 2-factorial treatment structure (packing X temperature) was used. The obtained data were analyzed through a multivariate analysis known as Principal Components Analysis, using S-plus 4.2. The conclusion was that the best packages to preserve the fruit were the ½ box ones, which proves that it is necessary to reduce the number of fruits per package to allow better ventilation and decreases mechanical injuries and ensure quality for more time.

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There is a lack of information about fertilization of pineapple grown in the State of São Paulo, Brazil. So a field experiment with pineapple 'Smooth Cayenne' was carried out to study the effects of NPK rates on yield and fruit quality. The trial was located on an Alfisol in the central part of the State of São Paulo (Agudos county). The experimental design was an incomplete NPK factorial, with 32 treatments set up in two blocks. The P was applied only at planting, at the rates of 0; 80; 160 and 320 kg/ha of P2 0(5), as superphosphate. The N and K2O rates were 0; 175; 350, and 700 kg/ha, applied as urea and potassium chloride, respectively, divided in four applications during the growth period. Response functions were adjusted to yield or to fruit characteristics in order to estimate the nutrient rates required to reach maximum values. The results showed quadratic effects of N and K on yield and a maximum of 72 t/ha of fresh fruit was attained with rates of 498 and 394 kg/ha, respectively of N and K2O. In order to reach the maximum fruit size, and to improve the percentage of first class fruit (mass greater than 2.6 kg), were necessary rates of N and K respectively 11 and 43 % higher than those for maximum yield. No effect of P rates was observed on pineapple plant growth, despite the low availability of this nutrient in the soil. The effect of N rates was negative on total soluble solids and total acidity while the opposite occurred with K, which increased also the content of vitamin C. High yield and fruit size were closely related to N and K concentrations in the leaves.

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The objective of research was to analyse the potential of Normalized Difference Vegetation Index (NDVI) maps from satellite images, yield maps and grapevine fertility and load variables to delineate zones with different wine grape properties for selective harvesting. Two vineyard blocks located in NE Spain (Cabernet Sauvignon and Syrah) were analysed. The NDVI was computed from a Quickbird-2 multi-spectral image at veraison (July 2005). Yield data was acquired by means of a yield monitor during September 2005. Other variables, such as the number of buds, number of shoots, number of wine grape clusters and weight of 100 berries were sampled in a 10 rows × 5 vines pattern and used as input variables, in combination with the NDVI, to define the clusters as alternative to yield maps. Two days prior to the harvesting, grape samples were taken. The analysed variables were probable alcoholic degree, pH of the juice, total acidity, total phenolics, colour, anthocyanins and tannins. The input variables, alone or in combination, were clustered (2 and 3 Clusters) by using the ISODATA algorithm, and an analysis of variance and a multiple rang test were performed. The results show that the zones derived from the NDVI maps are more effective to differentiate grape maturity and quality variables than the zones derived from the yield maps. The inclusion of other grapevine fertility and load variables did not improve the results.

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En este trabajo se presenta un protocolo para la zonificación intraparcelaria de la viña con la finalidad de vendimia selectiva. Se basa en la adquisición de una imagen multiespectral detallada en el momento del envero, a partir de la cual se obtiene el índice de vegetación de la diferencia normalizada (NDVI). Este índice se clasifica en áreas de vigor alto y bajo mediante un proceso de clasificación no supervisada (algoritmo ISODATA). Las zonas resultantes se generalizan y se transfieren al monitor de cosecha de una máquina vendimiadora para realizar la recolección selectiva. La uva recolectada según este protocolo en parcelas control ha mostrado diferenciación en cuanto a parámetros de calidad como el pH, la acidez total, el contenido de polifenoles y el color. La imagen multiespectral utilizada fue adquirida por el satélite Quickbird-2. Los datos de calidad de la uva fueron muestreados según una malla regular de 5 filas por 10 cepas, procediendo a un test estadístico de rangos múltiples para analizar la separación de medias de las variables analizadas en cada zona de NDVI.

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The acidity determinations method of humic acids (HA) content was developed by Schnitzer and Gupta and is a very well known procedure. Nevertheless, care is necessary to prevent measure errors due to non-controlled BaCO3 production, during the filtration and titration of HA total acidity. To overcome this problem, we developed in our laboratory a simple filtration and titration system for the determination of HA acidity under inert atmosphere. This system enables a better reproducibility and accuracy of total, carboxylic and phenolic acidity measures than those by Schnitzer and Gupta method.

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Samples of new insulating mineral oil, after contact with bauxite, were analyzed by visible spectrophotometry, impedance spectroscopy and their total acidity index was measured. The results of these analyses were compared to samples of new insulating mineral oil, which had not been in contact with bauxite. The comparison demonstrated that the bauxite didn't reduce the insulating capacity of the mineral oil and thus could be used to treat the oil in situ during the operation of an electric transformer.

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The production of cashew apple wine has the purpose of minimizing the wastage in the Brazilian cashew production. Knowing that the cashew apple fermentation produces a good cashew wine, a study of alcoholic fermentation kinetics of the cashew apple and the physico-chemical characterization of the product were made. The cashew wine was produced in an stirred batch reactor. The results of the physico-chemical analysis of volatiles, residual sugars, total acidity and pH of cashew wine showed that their concentrations were within the standard limits established by the Brazilian legislation for fruit wines.