摘要
【目的】探究干燥方式对细菌纤维素(Bacterial cellulose,BC)复水性能的影响。【方法】采用热风干燥、微波真空干燥和真空冷冻干燥3种干燥方式干燥BC,比较不同干燥方式对BC的溶胀率和复水量的影响,并对BC微观结构进行表征。【结果】不同干燥方式会影响BC结构,引起复水性能变化。与未干燥的BC相比,冷冻干燥的BC复水率达44.79%,复水性能较其他干燥方式好;热风干燥的BC的复水性能次之;微波真空干燥的BC的复水性能最差。电子扫描电镜结果分析表明,冷冻干燥的BC纤维丝排列疏松,较好地保持了BC的表面结构,热风干燥和微波真空干燥的BC纤维排列致密。从复水性能来看,冷冻干燥方法优于2种干燥方法,且在-80℃冷冻后进行冷冻干燥的细菌纤维素的复水性能最好。动力学分析表明,细菌纤维素复水过程遵循Fickian扩散定律,BC的网络结构保持的越完整,材料的扩散系数越高,对应的复水性能也越好。【结论】冷冻干燥的复水性能最好。
【Objective】 Effects of drying methods on rehydration property of bacterial cellulose(BC) were investigated.【 Method】 BC samples dried by means of hot air, microwave under vacuum, and freeze-drying were compared on the swelling and reconstitution rates upon rehydration. A scanning electron microscope(SEM) was used to observe and characterize the BC microstructure.【Result】 The varied dehydration processes affected the microstructure and rehydration of the dried BC. Among the untreated control and treated samples, the freeze-dried BC displayed the highest rehydration rate of44.79%. It was followed by the hot air and the microwave-vacuum dried specimens. The SEM images showed the freeze-drying rendered BC with a loose but well-defined fibrous network, while the other two methods produced a tight structure with clusters. Insofar as hygroscopic property is concerned, freeze-drying BC at-80 ℃ was superior to all other methods. The dynamics of the water adsorption and swelling of BC followed the Fickian diffusion law. A better maintained 3 D structure would have greater diffusion coefficient, and therefore, more efficient water absorption for the dried BC when water was added. 【Conclusion】 The freeze-dried BC could be rehydrated most desirably among all tested samples. The processing technology was recommended for the dehydration.
作者
郑梅霞
肖荣凤
陈梅春
陈燕萍
朱育菁
ZHENG Meixia;XIAO Rongfeng;CHEN Meichun;CHEN Yanping;ZHU Yujing(Institute of Agricultural Bio-resources Research,Fujian Academy of Agricultural Sciences,Fuzhou,Fujian 350003,China)
出处
《福建农业学报》
CAS
CSCD
北大核心
2021年第12期1499-1505,共7页
Fujian Journal of Agricultural Sciences
基金
福建省科技计划公益类专项(2019R1034-7)。
关键词
细菌纤维素
热风干燥
微波真空干燥
真空冷冻干燥
复水
Bacterial cellulose
hot air drying
microwave-vacuum drying
freeze drying
rehydration
