O objetivo deste trabalho foi avaliar os perfis proteicos e o desempenho fisiológico de sementes de café submetidas a diferentes métodos de processamento e secagem. Foram avaliados os processamentos por via seca e úmida, e as secagens natural, em terreiro, e artificial a 60ºC, ou a 60ºC até 30% de umidade e 40ºC até teor final de 11% (base úmida). Após serem processadas e secadas, as sementes foram avaliadas quanto ao desempenho fisiológico e submetidas a análises bioquímicas, por meio da eletroforese de proteínas resistentes ao calor LEA ("late embryogenesis abundant") e das enzimas superóxido dismutase, catalase, peroxidase, esterase, polifenoloxidase, isocitrato desidrogenase, álcool desidrogenase e malato desidrogenase. O perfil proteico de sementes de café é afetado pelo método de processamento e de secagem. Os cafés processados por via úmida apresentam maior tolerância à secagem - revelada pela maior atividade de enzimas antioxidativas e pelo melhor desempenho fisiológico - do que os processados por via seca. A atividade de proteínas resistentes ao calor e de enzimas antioxidantes é variável promissora para diferenciar a qualidade dos cafés submetidos a diferentes manejos pós-colheita.
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.
The ability of antioxidant compounds in vegetables to prevent disease is important for the pharmaceutical and food industries. In addition, water stress can enhance the existing antioxidant capacity of plants. As such, this study aimed to assess the effect of different irrigation depths and selenium application on the postharvest characteristics of cauliflower. A randomized block design was used in a 3 x 2 factorial scheme, with four repetitions. The first factor consisted of three irrigation depths with regulated deficit irrigation (RDI): severe (50% ETc) and moderate RDI (75% ETc) and complete irrigation (100% ETc), performed after inflorescence initiation, and the second of foliar spraying of selenium (with and without the element). Selenium application increased cauliflower yield under moderate RDI and no water/drought stress. Moderate RDI was the most effective strategy for maintaining yield and increasing the antioxidant capacity and phenolic compound content of cauliflower. Foliar spraying of selenium raised total polyphenol content under drought stress. Severe RDI extended the shelf life of cauliflower florets.
Water deficit in cauliflower cultivation may impair its development and yield. This study aimed to analyze the agronomic performance of cauliflower grown in a protected environment, under different water conditions and silicon (Si) doses. The experiment was arranged in a randomized block design, in a 3 x 4 factorial scheme, with three levels of water replacement [40, 70 and 100 % of the evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four replications. Leaf (SPAD index, area, fresh and dry weight), stem (diameter, height, fresh and dry weight) and inflorescence (diameter, fresh weight, dry weight, water content and commercial classification) characteristics were evaluated. The replacement of 40 % of the ETc showed lower results for the SPAD index in the phases II and III, leaf area, leaf and stem fresh weight and inflorescence diameter. The 70 % replacement cultivation showed a yield similar to that of the 100 % of the ETc. The use of Si was beneficial for the productive performance of the cauliflower at all levels of water replacement.
The objective of this work was to determine the accumulation of silicon in the plant components of cauliflower (Brassica oleracea var. botrytis) grown with different levels of water replacement and rates of Si. The experimental design was a randomized complete block with three water replacement conditions (40, 70, and 100% evapotranspiration), four Si rates (0, 50, 100, and 150 kg ha-1), and four replicates. Daily evapotranspiration was determined with constant water table lysimeters, with water replacement by a drip system. As a source of Si, silicon oxide was applied three times in the crop cycle - at the initial, intermediate, and final development stages of the plant. At the end of the cycle, samples of plant tissue (root, stem, leaves, and inflorescence) and soil were collected to determine Si by spectrometry. The Si content in the soil was not influenced by water replacement, only by silicate fertilization. The silicon applied to the soil increased the content of the element in the plant components, especially in the roots. Water replacement influences the accumulation of Si in cauliflower plant tissues, with lower amounts of the element under water deficit conditions.