Isotermas de sorção de umidade de abóbora (Cucurbita moschata) fresca e branqueada

Moisture desorption isotherms of fresh and heat blanched pumpkins (Cucurbita moschata) were determined at three temperatures (30, 50 and 70 °C), using the standard, static-gravimetric method. The GAB, Oswin, BET, Halsey, and Henderson models were tested and, with the exception of the Henderson model...

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Detalhes bibliográficos
Autores: Molina Filho, Lucídio [UNESP], Gonçalves, Ana Karla Rebes [UNESP], Mauro, Maria Aparecida [UNESP], Frascareli, Elen Cristina [UNESP]
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2011
País:Brasil
Recursos:Universidade Estadual Paulista (UNESP)
Repositório:Repositório Institucional da UNESP
Idioma:inglês
português
OAI Identifier:oai:repositorio.unesp.br:11449/226577
Acesso em linha:http://dx.doi.org/10.1590/S0101-20612011000300025
http://hdl.handle.net/11449/226577
Access Level:Acceso aberto
Palavra-chave:Blanching
Desorption isotherms
GAB model
Isosteric heat
Pumpkin
Descrição
Resumo:Moisture desorption isotherms of fresh and heat blanched pumpkins (Cucurbita moschata) were determined at three temperatures (30, 50 and 70 °C), using the standard, static-gravimetric method. The GAB, Oswin, BET, Halsey, and Henderson models were tested and, with the exception of the Henderson model, showed satisfactory fits to the experimental data. The GAB model was used to analyze the fitting ability to describe the isotherm type. The shape of the desorption isotherms of fresh and blanched pumpkin at 30 and 50 °C was intermediate to types II and III, and at 70 °C it was of type II for the blanched pumpkin and close to type II for the fresh sample. The influence of blanching on the decrease in equilibrium moisture was very small compared to the fresh samples and it was related to the loss of soluble solids during the pre-treatment. The isosteric heat of sorption measures indicated that a larger amount of heat was required to remove the water from the fresh samples than from the blanched ones.