DESENVOLVIMENTO DE METODOLOGIAS PARA MELHORAR A QUALIDADE DE HORTOFRUTÍCOLAS CONGELADOS: NOVOS PRÉ- -TRATAMENTOS E EFEITOS DE ABUSOS DE TEMPERATURA NA CADEIA DE DISTRIBUIÇÃO

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Modelling kinetics of watercress (Nasturtium officinale) colour changes due to heat and thermosonication treatments

Publication . Cruz, R. M. S.; Vieira, M. M. C.; Silva, C. L. M.

Watercress (Nasturtium officinale) colour changes due to blanching by heat and a combined treatment of heat/ultrasound (thermosonication) were studied in thetemperature range of 82.5 to 92.5 °C. The application of thermosonication was intended to enable less severe blanching treatments and, therefore, improve the quality of the blanched product. The thermosonication blanching processes promoted changes of the green colour (an parameter) at a higher rate (P < 0.05), when compared with the heat blanching processes. No significant differences (P > 0.05) were detected between heat and thermosonication blanching processes in terms of the colour parameters Ln, bn and TCD changes.In both treatments, a fractional first order model fitted well the experimental data for Ln, an and bn (RH2 = 0.99; RTs2 = 0.99) and TCD (RH2 = 0.92; RTs2 = 0.96) colour parameters. The chlorophylls content showed no significant differences (P > 0.05) between thermally treated and thermosonicated watercress samples. The present findings will help to evaluate the effectiveness of thermosonication as a novel process to replace the classical heat treatment.

2007-06Artigo científico

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Parallel implementation of a learning algorithm for multilayer perceptrons using transputers

Publication . Ruano, Antonio; Jones, D. I.; Fleming, P. J.

In this paper the parallelization of a new learning algorithm for multilayer perceptrons, specifically targeted for nonlinear function approximation purposes, is discussed. Each major step of the algorithm is parallelized, a special emphasis being put in the most computationally intensive task, a least-squares solution of linear systems of equations.

1992Documento de conferência

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Entidade financiadora

Fundação para a Ciência e a Tecnologia

Número da atribuição

SFRH/BD/9172/2002