期刊名称：Croatian Journal of Food Science and Technology
印刷版ISSN：1847-3466
出版年度：2009
卷号：1
期号：1
页码：15-23
出版社：Prehrambeno-tehnološki fakultet Osijek
摘要：The aim of this work was to investigate the influence of heating shelf temperature on selected physical properties of freeze-dried strawberries. Frozen strawberries were freeze-dried at heating shelf temperature of 10, 30, 50 and 70°C for 24 hours. Rehydration, adsorption rate and sorption isotherms were determined for freeze-dried strawberries. With increase the temperature of heating shelves in the range 10-50°C, rehydration capacity was increased. After 30 minutes of the rehydration process there was a decrease in water content, which is probably connected with changes in structure. Sorption isotherms were included to II isotherms type and have a sigmoidal shape characteristic for most food products. For the mathematical description Peleg’s model was used. For freeze-dried strawberries obtained in the range from 10 to 50°C isotherms have the same courses. Increase of temperature to 70°C resulted in obtaining the lowest water content in the water activity range from 0.113 to 0.648. There is a statistically significant influence of temperature of heating shelf on water vapour sorption for freeze-dried strawberries. For fruit freeze-dried in 30°C there was the highest water vapour sorption rate.
关键词：strawberries; freeze-drying; water sorption; kinetic; rehydration
