Acúmulo de antocianinas e características físicas e químicas de frutos de laranjas sanguíneas durante o armazenamento a frio

Este trabalho teve como objetivo avaliar o conteúdo de antocianinas no suco e as características físicas e químicas dos frutos de oito variedades de laranjas sanguíneas e de laranja Valência, e, também, verificar os efeitos do armazenamento dos frutos a 10ºC, durante um período de até 60 dias, nos parâmetros avaliados. Os teores de antocianina foram determinados utilizando-se de um método espectrofotométrico, assim como dez características físicas e químicas dos frutos e dos sucos foram avaliadas antes e durante o armazenamento. Todas as variedades de laranja avaliadas apresentaram naturalmente baixos teores ou nenhum teor de antocianina no suco. O armazenamento durante um período de até 60 dias, em baixa temperatura, possibilitou acúmulo significativo de antocianina no suco, porém de maneira desigual nas variedades de laranjas sanguíneas testadas. As variedades Moro foram as que apresentaram suco contendo os maiores teores de antocianina no final do armazenamento. À exceção de duas variedades, Sanguinelli (Marrocos e Polidari), as demais variedades sanguíneas avaliadas podem ser consideradas como semelhantes entre si e adequadas ao consumo. O armazenamento dos frutos a 10ºC, durante o período máximo de 60 dias, alterou significativamente somente as variáveis: largura de frutos, teor de SS, acidez e o rendimento de suco.

Caracterização física e química de frutos de mamey

O mamey (Pouteria sapota) é originário do México e América Central, sendo comum em Cuba, Norte da América do Sul e nas Índias Ocidentais. Porém somente após sua introdução na Flórida passou a ser mais conhecido e procurado, principalmente pelos latino-americanos. Para diversas fruteiras, a distinção entre variedades pode ser realizada com base em características dos frutos, permitindo a diferenciação dessas plantas. Diante disso, realizou-se o presente trabalho, verificando a possibilidade da distinção de plantas de mamey pertencentes à coleção do Banco Ativo de Germoplama, da FCAV, Câmpus de Jaboticabal-SP, através de características físicas e químicas dos frutos. Foram avaliadas: massa (g), comprimento (cm), diâmetro (cm), rendimento de polpa (%), acidez titulável (AT), sólidos solúveis (SS), ácido ascórbico (AA), pH e relação sólidos solúveis/acidez titulável de frutos de treze plantas de mamey. Com base nos resultados obtidos, pode-se concluir que existem diferenças significativas para todas as variáveis avaliadas entre as diferentes plantas de mamey, possibilitando a seleção de matrizes promissoras, para implantação de pomares comerciais.

Estabilidade de agregados de um latossolo vermelho tratado com cama de peru

Recentemente, tem ocorrido um grande aumento na produção de aves, com destaque para a carne de peru, motivado pelo aumento das exportações e a conquista de novos mercados. Como conseqüência, tem sido gerada uma grande quantidade de resíduos orgânicos com potencial impacto sobre o ambiente. A cama de peru constitui-se no principal resíduo dessa atividade avícola, e uma das formas de sua utilização é a sua disposição em solos como condicionador de suas características físicas e químicas. Assim, objetivou-se com este trabalho avaliar o efeito da aplicação da cama de peru na estabilidade de agregados de um Latossolo Vermelho Distrófico típico, sob pastagem de Brachiaria decumbens, localizado em Uberlândia, no Triângulo Mineiro, Minas Gerais. A cama de peru foi aplicada nas dosagens de: 0 (controle), 1.200, 2.400 e 4.800 kg ha-1 e 2.400 kg ha-1 + adubação mineral (36 kg ha-1 N, 60 kg ha-1 K2O e 60 kg ha-1de P2O5). As aplicações foram realizadas em janeiro de 2004 e o solo amostrado em duas épocas distintas (60 e 210 dias após aplicação) nas camadas de 0-20 e 20-40 cm para análise da estabilidade de agregados, avaliada pela percentagem total de agregados, percentagem de agregados maiores que 2mm, menores que 0,25mm e diâmetro médio geométrico (DMG). Não houve efeito das dosagens de cama de peru aplicadas na agregação do solo, entretanto, independentemente da dose aplicada houve um aumento na estabilidade de agregados, ao longo do tempo, notadamente na camada de 0-20 cm.

Desempenho e características de carcaça de novilhos suplementados no período das águas

Avaliaram-se os efeitos da suplementação concentrada de novilhos, durante o período das águas, sobre o desempenho e características da carcaça. Foram utilizados 49 novilhos mestiços, mantidos em pastagem de Brachiaria decumbens. O experimento foi conduzido em três períodos experimentais, segundo um delineamento inteiramente casualizado. Foram fornecidos sal mineral (SAL), suplementos à base de milho e farelo de soja, com 20% PB, em níveis de 1,0 e 2,0 kg/dia (MFS1 e MFS2), e suplementos à base de farelo de trigo e farelo de soja, com 20% PB, em níveis de 1,0 e 2,0 kg/dia (FTFS1 e FTFS2), fornecidos diariamente. Não foram encontradas diferenças entre os tratamentos sobre ganho de peso médio diário (GMD) e ganho total (GDP Total). Os GMD foram: 0,887; 0,936; 1,047; 0,943; e 1,012 kg/animal/dia, respectivamente, para os tratamentos SAL, MFS1, MFS2, FTFS1 e FTFS2. Os animais submetidos aos diferentes tratamentos não exibiram diferenças nas características físicas e químicas da carcaça. Não houve diferenças quanto ao rendimento de carcaça dos novilhos dos diferentes tratamentos, que foi, em média, de 52,19%.

The planktonic community in tropical interdunal ponds (Lencois Maranhenses National Park, Maranhao State, Brazil).

The aim of this study was to characterize the LenYois Maranhenses ponds (Maranhao State, Brazil) with respect to morphometry and physical and chemical aspects of the water body, in particular, the planktonic community. LenYois Maranhenses is a tropical coastal region with sand dunes and numerous interdunal ponds, most of them temporary. Ten ponds were studied, and a nictemeral variation was carried out. They have similar physical and chemical characteristics (high temperature - 27.5 to 32.0 [degree]C, acid pH - 4.9 to 6.2, low values of dissolved nutrients, chloride - 0.75 to 1.00 mg.L[long dash]1, and electric conductivity - 18.8 to 33.2 [mu]S.cm[long dash]1, and light penetration up to the sediment). With respect to the plankton, it is likely that the different histories of colonization, the formation of the ponds, and the initial organisms, affect the species richness, density and dominance observed. The lakes were classified as polymitic and oligotrophic.

Efeito da salinidade e do esgoto orgânico sobre a comunidade zooplanctônica, com ênfase nos copépodes, do estuário do rio Itanhaém, Estado de São Paulo

The objective of this work is to analyze the effects of salinity and wastewater on the zooplankton community of the Itanhaém river estuary, São Paulo state. Samples of zooplankton as well as physical and chemical variables of water were collected in four sites, located between the coastal line and the superior part of the estuary, including a secondary channel where wastewater is thrown without previous treatment. The samples were collected in low and high tide in winter and summer. Results showed that the estuary presents a temporal and spatial variation of physical and chemical characteristics, especially salinity, in function of the tide and seasonal variation of rain. The high values of salinity occurred in winter and high tide. Zooplankton community was adapted to the dynamic of salinity, and marine and estuarine species occurred in the low part of the estuary in winter. Although the Itanhaém river estuary has the same temporal and spatial dynamic of other estuaries, the values of salinity are low when compared with others located in the southern coast of São Paulo. Consequently, mainly oligohaline and fresh water species constitute the zooplankton community. These characteristics are due to the great drainage area of the Itanhaém river basin. The waste water modified physical and chemical characteristics of water that now presents higher concentrations of nutrients, higher values of suspended matter and lower concentrations of oxygen. It was observed a positive relation between the density of nauplii of copepods and organic pollution in this estuary.

Organização das assembléias de peixes em riachos da bacia do rio Iguatemi, Estado do Mato Grosso do Sul

Aiming to describe the patterns of the fish assemblages organization in streams of the Iguatemi River basin we sampled streams with seine nets and sieves from November/1999 to August/2000. We collected 567 individuals distributed in 24 species. We detected statistically significant influence of the streams characteristics upon species diversity. The species composition was hardly explained by the physical and chemical characteristics of the streams. Then we detected significant influence of the fish ecomorphology in the species occurrence (Mantel r = -0.34; P = 0.04), but not in the distribution of its abundance (Mantel r = -0.21; P = 0.07). We verified through the species co-occurrence index (C-score) that its composition in the studied streams is stochastic.

Uso de métodos químicos para obtener polvos cerámicos del sistema (Sn, Ti)O2

The (Sn,Ti)O2, system has a great interest due to its technological applications such as gas sensor and varistor. Although the thermodynamic properties and the kinetics of spinoidal decomposition in this system have been extensively studied, the general properties and applications of SnO2 - TiO2 binary compositions have been not investigated yet in depth. On the other hand, little work has been done to optimize the synthesis methods to obtain (Sn,Ti)O2 cerallmic powders, with pre - determinate physical and chemical characteristics. In this work the ceramic powders has been obtained by coprecipitation and polymeric precursor (Pechini) methods. The different physical chemistry phenomena that occurred during the synthesis were discussed. The (Sn,Ti)O2, ceramic powders were characterized with X- ray diffraction (XRD), thermal analysis (DTA/TG) and scanning electron microscopy (SEM). The knowledge about of steps and variables of synthesis process acquired with development of this work, we permited to obtain (Sn, Ti)O2, nanometers particles to low temperatures: to 450°C for coprecipitation method and to 600°C for Pechini method. The spinodal decomposition that ocurr to 900°C was discussed also.

Preliminary selection of acerola genotypes in Brazil

Introduction. Breeding studies for acerola (Malpighia glabra) improvement aim at obtaining plants that produce fruits with uniform chemical and physical attributes, including high levels of vitamin C, which can provision the market with fresh fruit and frozen pulp. High variability in fruit quality is observed in Brazilian acerola crops, especially those propagated by seeds. In this context, the objective of our research was to evaluate the physical and chemical characteristics of Brazilian acerola genotype fruits. Materials and methods. Sixteen acerola genotypes were studied in Jaboticabal, São Paulo State, Brazil. A completely randomized design with sixteen treatments and six replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quality, such as width, length, weight, pulp percentage, soluble solids (SS), titratable acidity (TA), [SS / TA] ratio and vitamin C content, were evaluated in fruits of the acerola genotypes. The results were submitted to variance analyses, the Tukey test and cluster analysis. Results and discussion. There was a statistical difference between the acerola genotypes studied. Three of them stood out as natural sources of vitamin C. In spite of fruit size, two acerola genotypes were found to have potential for fresh fruit production. In a general form, genotypes that presented a high [SS / TA] ratio had low vitamin C content. Conclusion. The acerola genotypes studied in Jaboticabal presented high variability, forming eleven groups in relation to fruit quality parameters. © 2007 Cirad/EDP Sciences All rights reserved.

Phytoplankton primary productivity in an urban eutrophic reservoir (São Paulo, Brazil)

The aim of this study was to analyze temporal ..d vertical variation of the biomass and of phytoplankton primary productivity in an urban eutrophic reservoir, in relation to the physical and chemical characteristics of the water. The physical and chemical variables of the water were defined in the limnetic region of the reservoir, at depths of 0.0; 0.5; 1.0; 2.0; 3.0 and 4.0 meters. Three samples were taken to define both the physical and chemical variables, concomitantly with the biomass (chlorophyll-a and phaeophytin) and phytoplankton primary productivity (C-14 method). Based on data obtained on differences in depth of the mixture zone and the euphotic zone, it is hypothesised that, depending on the time of the year, phytoplankton is conditioned by differences in the light and nutrient regimes, which change according to the constant loads of nutrients thrown into the system. The highest concentration of chlorophyll-a in the photic zone of the limnetic region was observed in November 2000 (1,197.3 mg Chl L -1) and the lowest in November 1999 (94.0 mg ChI L -1), whereas the profiles of primary activity of phytoplankton presented the highest rates on the surface of the water column, with values varying from 84.7 (May 2000) to 1,376.7mg C m -3 h -1 (December 2000). Annual primary productivity was calculated at 1,567.0gC m -2y -1, considered euproductive. The primary productivity profiles reported in this study are typical of aquatic eutrophic systems, rich in plankton and with low light penetration. It can be stated that Garças Lake is a system that suffers from anthropogenic impact, through receiving large loads of organic pollution, reflecting on the physical and chemical characteristics of the water and on the high values of biomass and primary phytoplankton activity. © National Institute of Ecology, New Delhi.

Restoration of a degraded area using soil tillage systems in Campinas, São Paulo, Brazil

In Brazil the intensive agriculture use, mainly pasture, is the main cause of the presence of extensive areas of degraded lands. This study aimed to assess the impact of different soil management practices in a pasture degraded area used as garbage disposal. The experiment was performed at the Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas - UNICAMP, in Campinas, state of São Paulo, Brazil, from 1990 to 1996. This area has undergone a process of recovery through removal of trash deposited on the surface, in 1985, levelling of soil, followed by application of limestone, subsoiling, planting of legumes (Crotalaria juncea) and crop rotation (soybean and maize). Since 1990 only popcorn maize was grown and established plots managed with different soil tillage systems, including harrow, chisel plow, moldboard plow, no tillage, disk plow and revolving hoe. One plot was planted exclusively with guinea grass (Panicum maximum) to serve as a reference for minimum loss of soil and another grown on a downhill direction to correspond to the expected maximum erosion. There were differences in sediment loss, nutrient loss and productivity of the popcorn maize in the period analyzed. The chisel plow and no tillage treatments caused the slightest loss of soil and nutrients, compared to other tillage systems. The results show that the soil management systems influenced the physical and chemical characteristics of soil, allowing an economical and environmental recovery of the area, providing the conditions for grain agricultural production.

Efeitos de óleos nas características físicas e químicas da calda de aplicação e na ação da atrazina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de resíduos vegetais de milheto (Pennisetum americanum) e da calagem em algumas propriedades físicas de um nitossolo vermelho em sistema de semeadura direta

Pós-graduação em Agronomia (Agricultura) - FCA

Síntese e caracterização de partículas de poli(álcool vinílico) utilizadas em aplicações biomédicas: contribuição da análise fractal e entropia de Shannon

Pós-graduação em Biofísica Molecular - IBILCE

Poliuretana contendo corante azóico e espaçador tipo bis-carbonato como material para fabricação de filmes nanoestruturados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)