水分含量对草莓玻璃化转变温度的影响  

Effect of Water Content on the Glass Transition Temperature of Strawberry

作　　者：叶秀东[1] 周国燕[1] 华泽钊[1] 闫琰[1] 

机构地区：[1]上海理工大学低温医学与食品冷冻研究所,上海200093

出　　处：《食品科学》2006年第11期71-74,共4页Food Science

基　　金：国家自然科学基金(50206013);上海市重点学科建设项目(T0503)

摘　　要：在冻干和低温保存中,玻璃化转变温度是一个非常重要的参数。本文用差示扫描量热仪测量得到不同湿基水分含量的草莓汁的玻璃化转变温度。实验发现水分含量较高时(>50%),草莓发生的是部分玻璃化转变,不同湿基水份含量草莓汁的Tg'基本相同,水分对其的影响较小。而水分含量较低时(<45%),草莓降温时往往出现完全玻璃化转变,不同湿基水分含量草莓的Tg有很大不同,完全玻璃化转变温度随着水分含量的减少而升高,拟合得到Tg随水分变化的公式。Glass-transition temperature is a very important parameter in freeze-drying and cryopreservation. The glasstransition temperature of strawberry with different water content are measured using DSC. It is found that the partial glass transition appears when the water content of strawberry is higher than 50%. The Tg＇ of strawberry with different water content are same and the water content has little influence on it. The complete glass transition appears when the water content is lower than 45%. The water content has great influence on Tg. The Tg increases with the decrease of water content. The function between Tg and the water content is gotten.

关 键 词：玻璃化转变温度 草莓 差示量热扫描 部分玻璃化转变温度 

分 类 号：TS201.7[轻工技术与工程—食品科学]