Autor(es):
Guiné, Raquel 
; Barroca, Maria João ; Lopes, Paulo ; Silva, Vitor ; Lima, Maria João ; Ferreira, Dulcineia
Data: 2010
Identificador Persistente: http://hdl.handle.net/10400.19/1337
Origem: Repositório Científico do Instituto Politécnico de Viseu
Assunto(s): Pear; Colour
Descrição
Pears of the variety S. Bartolomeu (Pyrus communis L.) have been used over the years in
Portugal to produce a traditional dried pear known as “pera passa”. It is a very much appreciated dried
fruit, despite the drop in the production that has occurred during the past years. The processing
comprehends a solar drying performed at open air, with obvious disadvantages, either concerning the
drying efficiency or the sanitary quality of the final product, taking into account that the products are
exposed to multiple contamination agents. Obviously, these handicaps do not guarantee the
necessary quality and sanitary standards for commercialization. Therefore, in the past years some
work has been done in order to encounter alternative reliable drying methods that can replace the
traditional drying. These include the use of solar stoves, either with forced air convection or with
natural convection, and a drying tunnel with air heated though a solar collector. However, not only the
drying efficiency and economic or sanitary aspects matter in the present case, since this particular
product is very much appreciated for its unique colour. In fact, these pears in particular, when dried by
the traditional method, develop a reddish colour that is not found in other varieties of pears, and this
aspect constitutes one of the quality parameters for their acceptability by the consumers.
The present work aims at comparing the colour of the pears dried by different methods, in order to
evaluate which method allows the obtaining of a final product as much similar as possible to the
traditional one.
