Effect of salts on the properties of aqueous sugar systems, in relation to biomaterial stabilization. 1. Water sorption behavior and ice crystallization/melting
Effect of salts on the properties of aqueous sugar systems, in relation to biomaterial stabilization. 1. Water sorption behavior and ice crystallization/melting
复制标题
DOI：
10.1006/cryo.2001.2345
复制
发表时间：
2001-11-01
期刊：
影响因子：
2.7
通讯作者：
Buera, MP
中科院分区：
文献类型：
--
作者：
Mazzobre, MF;Longinotti, MP;Buera, MP
海藻糖和蔗糖是在极端条件下保护生物的两种糖，它们与盐的混合物被用来制备过冷或冷冻干燥的玻璃系统。本工作的目的是探索不同的盐对水的吸附、玻璃化转变温度(T_I)以及在含水的糖体系中冰的形成和融化的影响。在糖-盐混合物中，根据各纯组分的吸水率，吸水率高于预期。在水的质量分数降低(w小于或等于0.4)的体系中，盐延迟了水的结晶，这可能是由于离子-水相互作用所致。在w>；0.6的体系中，水的结晶可以用已知的溶质的综合性质来解释，盐的存在降低了最大浓缩基质的玻璃化转变温度(T-g‘)。然而，系统的实际T1值没有被修改。因此，盐对冰的吸附行为和形成的影响可能反映了在分子水平上发生的动态水-盐-糖相互作用，并且与存在的阳离子的电荷/质量比有关，而不影响超分子或宏观性质。(C)2001年埃尔塞维尔科学公司(美国)。
Trehalose and sucrose, two sugars that are involved in the protection of living organisms under extreme conditions, and their mixtures with salts were employed to prepare supercooled or freeze-dried glassy systems. The objective of the present work was to explore the effects of different salts on water sorption, glass transition temperature (T,), and formation and melting of ice in aqueous sugar systems. In the sugar-salt mixtures, water adsorption was higher than expected on the basis of the water uptake by each pure component. In systems with a reduced mass fraction of water (w less than or equal to 0.4), salts delayed water crystallization, probably due to ion-water interactions. In systems where w > 0.6, water crystallization could be explained by the known colligative properties of the solutes, The glass transition temperature of the maximally concentrated matrix (T-g') was decreased by the presence of salts. However, the actual T, values of the systems were not modified. Thus, the effect of salts on sorption behavior and formation of ice may reflect dynamic water-salt-sugar interactions which take place at a molecular level and are related to the charge/mass ratio of the cation present without affecting supramolecular or macroscopic properties. (C) 2001 Elsevier Science (USA).