Electrodes modified with poly(5-amino-1-naphthol)/Prussian blue (poly(5-NH2-1-NAP)/PB) hybrid films are able to electrochemically reduce H2O2 in medium containing an excess of Na+ cations. This is an important advantage for biosensing applications over electrodes in which only conventionally (electro) deposited Prussian blue is present. Consequently, the aim of this work was to examine the application of templates of ordered arrays of colloidal poly(styrene) spheres (800, 450 and 100 nm in diameter) to produce inverse opal structures of poly(5-NH2-1-NAP)/PB hybrid platforms, in an effort to study the influence of the increase in surface area/volume ratio and higher exposition of the mediator active sites on material performance during H2O2 determination employing the different sized porous structures. Moreover, since the accentuated hydrophilic character of poly(5-NH2-1-NAP)/PB also allows H2O2 electrochemical reduction in inner active sites, issues concerning the amount of mediator electrodeposited on the electrode were also reflected in the observed results.

Neste trabalho caracterizou-se a qualidade dos frutos em diferentes pontos de colheita para armazenamento das cultivares de maracujá: BRS Gigante Amarelo, BRS Ouro Vermelho e BRS Sol do Cerrado. Foram avaliados as características físicas dos frutos (aparência, perda de massa, coloração da casca) e os parâmetros químicos do suco (conteúdo de acidez, pH, ácido ascórbico, sólidos solúveis totais, açúcares solúveis totais e açúcares redutores). Utilizou-se uma Amostragem Simples ao Acaso (ASA), com 0,05 de significância e as médias foram comparadas pelo Teste "t" por Intervalo de Confiança. Os frutos colhidos nos estádios iniciais de amadurecimento apresentaram maior perda de massa e alteração da qualidade do suco. Conclui-se que os frutos das diferentes cultivares colhidos na safra de verão (novembro/dezembro) devem ter pelo menos 55% de casca com coloração amarela para proporcionar menor perda de massa, manter a qualidade do suco e aumentar a sua vida útil.

In this study the fruit quality was characterized at different harvest points for storage of varieties of passion fruits: BRS Gigante Amarelo, BRS Ouro Vermelho and BRS Sol do Cerrado. The physical characteristics of fruits (appearance, mass loss and peel color) and chemical parameters of juice (content of acidity, pH, ascorbic acid, total soluble solids, total soluble sugars and reducing sugars) were characterized. The method of Simple Random Sampling (SRS) was applied, with 0.05 level of significance, and means were compared using the "t" Test for Confidence Intervals. Fruits harvested in the early ripening stages showed a higher mass loss as well as the worst juice quality. It was concluded that fruits of different cultivars harvested in summer seasons must present at least 55% of yellow peel color to render the lower mass loss, the best quality of juice and to extend the storage time.