摘要
为了获得预冻及其预处理条件对冻干罗非鱼片性能的影响规律,以新鲜罗非鱼为原料,进行了不同的预冻速度和不同的冻干预处理试剂浸渍处理对冻干罗非鱼片的干燥过程和干燥品质的影响试验,获得了不同预冻处理条件下的冻干曲线和干燥温升速率曲线,并以剩余含水率,水分活度,复水率和色泽等指标进行比较分析。结果表明:预冻速度会影响罗非鱼的升华干燥时间,且预冻速度越小,物料随着温度的变化表现越平缓。在本实验条件下,对残余含水率要求不太高的罗非鱼片来说,1.5 cm/h预冻速度获得的干品综合指标较优;其次,以蔗糖/山梨醇,柠檬酸钠和海藻糖三种预处理试剂及其不同浓度进行预处理试验的结果表明,经柠檬酸钠预处理后可以有效提高样品的冻干速率,且以10%柠檬酸钠预处理效果最好,样品含水率为5.63%,其水分活度为0.3917,复水率为46.71%,而海藻糖对冻干样品具有一定的保护作用,获得样品最高复水率为51.33%,最大白度值为79.64%。
The impacts of the pre-treatment conditions, including the pre-freezing rate, immersion solutions, and freezing temperature, on vacuum freeze-drying of Tilapia fillets were experimentally studied by evaluating its lyophiliza- tioncharacteristics, such as the moisture content, water activity, rehydration ratio, color and luster. The results show that the pre-freezing rate significantly affects the vacuum sublimation-drying time of Tilapia fillets. For example, a lower pre-freez- ing rate results in a smaller temperature fluctuation. Under mild requirement on the moisture content of vacuum freeze- dried Tilapia fillets, the compromised conditions include： a pro-freezing rate of 1.5 cm./h, and a mixed solution of sor- bitol, sucrose, sodiumcitrate（ 10% ）, and trehalose. The moisture content, water activity, and rehydration ratio were found to be 5.63 %, 0. 3917, and 46.71%, respectively. With protection of trehalose, the highest rehydration ratio and maximum whiteness were measured to be 51.33 % and 79.64%, respectively.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第6期559-564,共6页
Chinese Journal of Vacuum Science and Technology
基金
广东省海洋渔业科技推广专项(A201001C05)
广东海洋大学自然科学基金项目(1212329)
关键词
罗非鱼
真空冷冻干燥
预冻速度
预处理试剂
水分活度
含水率
Tilapia fish, Vacuum freeze drying, Prefreezing speed, Pretreatment reagents, Water activity, Moisture content
作者简介
Tel：13692419580；E-mail：limin2080@163．com
