Microwave and convective dehydration of ethanol treated and frozen apple - Physical properties and drying kinetics

TY - JOUR

T1 - Microwave and convective dehydration of ethanol treated and frozen apple - Physical properties and drying kinetics

AU - Funebo, Tomas

AU - Ahrné, Lília

AU - Prothon, Frédéric

AU - Kidman, Siw

AU - Langton, Maud

AU - Skjöldebrand, Christina

PY - 2002

Y1 - 2002

N2 - The objective of this study was to examine how the drying kinetics and physical properties of apples are affected by pre-treatment with 95% ethanol or freezing at -18 °C before microwave-assisted air dehydration at 50, 60 and 70 °C. Microwave heating was used to obtain these temperatures in the centre of the apple cubes. After dehydration the shrinkage and rehydration capacity were measured. The texture of dehydrated and rehydrated samples was analysed with a puncture test in a texture analyser. Samples were also analysed with confocal laser scanning microscopy to determine the correlation between physical and microstructural properties. Diffusivity in the different dehydration processes was calculated. Ethanol-treated apples showed both high rehydration and high effective rehydration capacity compared with the other samples. Freezing before dehydration increased the diffusivity and reduced the firmness of rehydrated apples compared with no pre-treatment.

AB - The objective of this study was to examine how the drying kinetics and physical properties of apples are affected by pre-treatment with 95% ethanol or freezing at -18 °C before microwave-assisted air dehydration at 50, 60 and 70 °C. Microwave heating was used to obtain these temperatures in the centre of the apple cubes. After dehydration the shrinkage and rehydration capacity were measured. The texture of dehydrated and rehydrated samples was analysed with a puncture test in a texture analyser. Samples were also analysed with confocal laser scanning microscopy to determine the correlation between physical and microstructural properties. Diffusivity in the different dehydration processes was calculated. Ethanol-treated apples showed both high rehydration and high effective rehydration capacity compared with the other samples. Freezing before dehydration increased the diffusivity and reduced the firmness of rehydrated apples compared with no pre-treatment.

KW - Drying

KW - Effective rehydration

KW - Microstructure

KW - Rehydration

KW - Texture

U2 - 10.1046/j.1365-2621.2002.00592.x

DO - 10.1046/j.1365-2621.2002.00592.x

M3 - Journal article

AN - SCOPUS:0036331167

SN - 1365-2621

VL - 37

SP - 603

EP - 614

JO - International Journal of Food Science and Technology

JF - International Journal of Food Science and Technology

IS - 6

ER -