Instability and structural change in an aerated system containing egg albumen and invert sugar
Instability and structural change in an aerated system containing egg albumen and invert sugar
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DOI：
10.1016/j.foodhyd.2004.04.020
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发表时间：
2005-01-01
影响因子：
10.7
通讯作者：
Dickinson, E
中科院分区：
文献类型：
--
作者：
Lau, CK;Dickinson, E
本文研究了含2- 6wt%蛋清的不稳定充气糖体系的不稳定机理和动态结构变化。降低浆液相中的转化糖浓度（从82%总固体）产生高得多的膨胀率的泡沫，但其导致增加的不稳定速率。对于具有< 60%糖的样品，可以容易地检测到液体排出。在静置时，观察到在泡沫柱中出现由不同气泡组成的三个单独的层。泡沫半衰期和初始排水率主要由糖含量（粘度效应）和搅打时间（蛋白质聚集效应）控制。通过共聚焦显微镜获得的一系列图像说明了泡沫演化过程中发生的复杂的动态结构变化。不稳定化过程似乎主要涉及大气泡的乳状液分离和不同大小的紧密相邻气泡的乳状液分离的组合。一些老化样品的中间泡沫层的共聚焦显微镜揭示的一个有趣的功能是形成的絮凝均匀的小气泡组成的凝胶状网络。观察到该气泡网络被移动的液体孔渗透，该液体孔允许一些较大的气泡在重力驱动的流体动力学流动的影响下穿过该网络。(C)2004爱思唯尔有限公司保留所有权利。
lnstability mechanisms and dynamic structural changes have been investigated for an unstable aerated sugar system containing 2-6 wt% egg albumen. Reducing the invert sugar concentration in the serum phase (from 82% total solids) produced a foam of much higher overrun, but it led to an increased rate of destabilization. Liquid drainage could be readily detected for samples with < 60% sugar. On standing, three separate layers consisting of different bubble compositions were observed to appear in the foam column. Foam half-life and initial drainage rate were mainly controlled by the sugar content (viscosity effect) and the whipping time (protein aggregation effect). A series of images obtained by confocal microscopy illustrates the complex dynamical structural changes that took place during foam evolution. The destabilization process appeared mainly to involve a combination of creaming of large bubbles and disproportionation of closely neighbouring bubbles of different sizes. An interesting feature revealed by confocal microscopy of the middle foam layer of some aged samples was the formation of a gel-like network composed of flocculated uniform small bubbles. This bubble network was observed to be permeated by mobile liquid pores which allowed some of the larger bubbles to pass through the network under the influence of gravity-driven hydrodynamic flow. (C) 2004 Elsevier Ltd. All rights reserved.