Roos Yrjö H
School of Food and Nutritional Sciences, University College Cork, T12 YK8AF Cork, Ireland.
Foods. 2021 Feb 18;10(2):447. doi: 10.3390/foods10020447.
Noncrystalline, freeze-concentrated structures are formed during food freezing. Such freeze-concentrated food materials often exhibit crystallization and recrystallization phenomena which can be related to the state of solutes and water. State diagrams are important tools in mapping the physical state and time-dependent properties of frozen materials at various storage temperatures. Transition of simple solutions, such as sucrose, can be used to describe vitrification and ice melting in freeze-concentrated materials. A maximally freeze-concentrated material often shows glass transition at T'. Ice melting occurs at temperatures above T' These transitions at temperatures above T' can be used to estimate crystallization and recrystallization phenomena and their rates in frozen foods. Furthermore, frozen food deterioration accelerates above T' and particularly as a result of temperature fluctuations during frozen food distribution and storage.
食品冷冻过程中会形成非晶态的冷冻浓缩结构。这种冷冻浓缩的食品材料常常表现出结晶和重结晶现象，这些现象可能与溶质和水的状态有关。状态图是描绘冷冻材料在不同储存温度下的物理状态和随时间变化特性的重要工具。诸如蔗糖等简单溶液的转变可用于描述冷冻浓缩材料中的玻璃化转变和冰融化。最大冷冻浓缩材料通常在T'处出现玻璃化转变。冰融化发生在高于T'的温度下。这些高于T'温度下的转变可用于估计冷冻食品中的结晶和重结晶现象及其速率。此外，冷冻食品在高于T'时变质加速，特别是在冷冻食品分销和储存期间温度波动的情况下。
