No abstract

“Natural” amines in plants, endogenous constituents of tissues, are involved in different physiological processes such as fruit development and senescence. Their levels can vary depending on variety, ripening, and storage conditions. Moreover, microbial contamination results in the increase of the “biogenic” amine content of fruits and vegetables. Electrochemical biosensors for the determination of the amine content in fruits have been assembled using diamine oxidase and polyamine oxidase covalently immobilized onto polymeric membranes. Both enzymes in the presence of their substrates produced H2O2 that was detected at a platinum electrode polarized at +650 mV versus Ag/AgCl. The best analytical conditions for the two enzyme electrodes have been optimized. The main positive effect of packaging fresh fruits with polymeric films is the provision of a barrier to the gas diffusion; the reduced O2 and increased CO2 concentrations slow the respiration rate. The films also allow the maintenance of high relative humidity with reduction of water loss. To investigate the postharvest life of apricots and sweet cherries in modified atmosphere storage at 0 °C, the concentration of amines in fruits packaged using different polymeric films was monitored. Keywords: Modified atmosphere packaging (MAP); polymeric film; electrochemical biosensor; amine; diamine oxidase; polyamine oxidase; sweet cherry; apricot fruit; postharvest

Consumo hídrico e coeficiente de cultura para o híbrido DKB 390 Consumo hídrico e coeficiente de cultura para o híbrido DKB 390 Consumo hídrico e coeficiente de cultura para o híbrido DKB 390 Consumo hídrico e coeficiente de cultura para o híbrido DKB 390 RESUMO. O objetivo deste trabalho é caracterizar o consumo hídrico do genótipo DKB 390 em condições adequadas de irrigação, tanto para situações de suprimento suficiente quanto para subótimo de nitrogênio. Valores de coeficiente de cultura são também apresentados para diferentes fases, para o primeiro caso, no intuito de prover subsídios teóricos para orçamento de água à cultura e para o manejo da irrigação durante o ciclo. Um experimento de campo foi conduzido durante a estação principal de cultivo, avaliando-se biomassa, área foliar, umidade do solo, dados climatológicos e transmitância de luz, permitindo derivar o balanço hídrico, o consumo hídrico e a eficiência de uso da água. O genótipo mencionado requer por volta de 600 mm para a obtenção de elevadas produções e apresenta menor eficiência de uso da água quando submetido a níveis subótimos de adubação nitrogenada.Palavras-chave: Zea mays, evapotranspiração, nitrogênio, biomassa, Kc, milho.ABSTRACT. Water use and crop coefficient for hybrid DKB 390. This work aims to characterize the water use of maize hybrid DKB 390 under suitable conditions of irrigation for both sufficient and below-optimal situations of nitrogen supply. Crop coefficient values for different stages are also presented as a result, in order to provide the basis for crop water budget and management throughout the cycle. A field experiment was carried out during the main season, in which biomass, soil moisture, leaf area, climate data and light transmittance were evaluated. These have allowed deriving water balance, use and efficiency. The mentioned genotype requires around 600 mm for high yield targets, being less efficient when led under below-optimal nitrogen fertilization.

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Describes a new process (Poly-Protein) for obtaining leaf protein concentrates from alfalfa juice by means of polyelectrolytes. Working conditions and the chemical composition of the products are reported. In particular 50L of juice, obtained by pressing 100 kg of fresh alfalfa, gave 1.6 kg of dry green LPC. The product so obtained has a high protein content and is particularly valuable for its several prospective uses in the feed industry.