José Henrique da Silva Taveira

Função de resposta da alface americana aos níveis de água e adubação nitrogenada

Objetivando-se estudar o efeito das lâminas de agua, doses de nitrogenio e sua interacao sobre os rendimentos produtivo e economico da cultura da alface americana irrigada por gotejamento, conduziu-se um experimento em casa-de-vegetacao localizada na Universidade Federal de Lavras, Minas Gerais, no periodo de setembro a novembro de 2004. O delineamento experimental foi fatorial 4 x 4 em blocos casualizados, sendo que os tratamentos constituiram-se da combinacao de quatro lâminas de irrigacao (W1=91,99; W2=142,79; W3=186,34; W4=237,14 mm) com quatro niveis de adubacao nitrogenada (N0=0; N1=80; N2=160; N3=320 kg ha-1) e com tres repeticoes. Utilizou-se a cultura da alface americana, cultivar Raider, irrigacoes diarias controladas com base na evaporacao de um minitanque (EVm), sendo os tratamentos W1,, W2, W3 e W4, correspondentes a 0,35EVm, 0,70EVm, 1,0EVm e 1,35EVm, respectivamente. A cultura foi instalada no espacamento de 0,30 m x 0,30 m, irrigada por um sistema de irrigacao por gotejamento, com gotejadores autocompensantes de 1,6 L h-1 de vazao, espacados de 0,3 m. Apos a analise dos resultados concluiu-se que a aplicacao de 205,26 mm de agua e de 257,14 kg ha-1 de nitrogenio proporcionou estimar uma produtividade maxima de 26.959,93 kg ha-1 que correspondeu a obtencao do lucro maximo, considerando os precos dos fatores agua (R

Activity of some isoenzymatic systems in stored coffee grains.

0,44 mm-1), nitrogenio (R

Perfis proteicos e desempenho fisiológico de sementes de café submetidas a diferentes métodos de processamento e secagem

2,09 kg-1) e da alface americana (R

Potential markers of coffee genotypes grown in different Brazilian regions: A metabolomics approach

0,80 kg-1). A produtividade fisica maxima de 27.004,49 kg ha-1 foi estimada com 208,03 mm e 290,5 kg ha-1 de nitrogenio. O menor valor medio da produtividade comercial da alface americana (13.814,25 kg ha-1) foi obtido no tratamento onde foi aplicada a menor lâmina de agua (91,99 mm). Essa produtividade e inferior aquela obtida no tratamento com dose 0 kg ha-1 de nitrogenio, cuja produtividade media foi de 19.943,7 kg ha-1.

Fatty acid profiles and parameters of quality of specialty coffees produced in different Brazilian regions

Considering the worldwide consumption of coffee, it is natural that throughout the history many people have dedicated the research to markers that contribute somehow on gauging its quality. This research aimed to evaluate the biochemical performance of arabica coffee during storage. Coffee in beans (natural) and in parchment (pulped) dried in concrete terrace and in dryer with heated air were packed in jute bags and stored in not controlled environmental conditions. Enzymatic activities of superoxide dismutase, catalase, peroxidase, polyphenoloxidase, esterase and lipoxygenase in coffee grains were evaluated at zero, three, six, nine and twelve months by means of electrophoresis. Independently of the drying method, the activity of isoenzymatic complexes highlighted deteriorative processes in stored grains of coffee. The treatments 60/40o C and 60o C used to reduce the water content imposed a greater stress condition, accelerated metabolism of natural coffee in the storage with decreased activity of defense mechanisms due to latent damage in these grains. Natural coffees are more sensible to high drying temperatures and its quality reduces faster than pulped coffee in the storage.

Effect of intermittent drying and storage on parchment coffee quality

The objective of this work was to evaluate the protein profiles and physiological performance of coffee seeds subjected to different drying and processing methods. We evaluated processing by dry and wet routes, the drying methods: natural, on the patio, and artificial at 60oC, or at 60oC until 30% of moisture content and 40oC until 11% (wet basis). After processing and drying, the seeds were evaluated as to their physiological performance and subjected to biochemical analyses with electrophoresis of heat‑resistant LEA (late embryogenesis abundant) proteins and of the enzymes superoxide dismutase, catalase, peroxidase, esterase, polyphenol oxidase, isocitrate dehydrogenase, alcohol dehydrogenase, and malate dehydrogenase. The protein profile of coffee seeds is affected by the processing and drying methods. The coffee processed by wet route has higher tolerance to drying - shown by the higher activity of antioxidative enzymes and better physiological performance - than that processed by dry route. The activity of heat‑resistant proteins and antioxidant enzymes is a promising variable for the differentiation of the quality of coffee subjected to different postharvest management.