Influence of different drying methods on tbe rheological properties of raisins
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Data
2001-01-01
Autores
Telis-Romero, J.
Gabas, A. L.
Rossi, S. J.
Telis, VRN
Título da Revista
ISSN da Revista
Título de Volume
Editor
Isnt Tecnologico Veracruz
Resumo
The rheological parameters of raisins were obtained after three different drying methods: convective, osmo-convective and solar drying. Compression tests were applied to rehydrated samples by using a Texture Analyzer TAXT2i. A mathematical trick was used to determine the stress and area was calculated along the deformation. A power law model could adequately fit stress-true strain curves and parameters; K (measure of stiffness) and n (solid behavior index) were obtained as a function of water activity between 0.755 to 0.432. Results showed that these parameters were strongly dependent on water activity for all drying methods. The constant K, which indicates the resistance against deformation, increased with decreasing water activity. on the other hand, increasing water activity resulted in higher solid behavior indexes, showing a large deviation from the Hookean behavior.
Descrição
Palavras-chave
rheological properties, raisins, osmo-convective, solar drying, compressive test
Como citar
Proceedings of the Second Inter-american Drying Conference. Veracruz 91860: Isnt Tecnologico Veracruz, p. 443-452, 2001.