The influence of solution viscosities and surface tension on calcium-alginate microbead formation using dripping technique
The influence of solution viscosities and surface tension on calcium-alginate microbead formation using dripping technique
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DOI：
10.1016/j.foodhyd.2016.06.029
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发表时间：
2017-01-01
影响因子：
10.7
通讯作者：
Poncelet, Denis
中科院分区：
文献类型：
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作者：
Davarci, Fatma;Turan, Deniz;Poncelet, Denis
目前，人们对使用海藻酸钙微球或珠粒包封生物活性成分的兴趣越来越大。钙在藻酸盐液滴中的扩散引起离子凝胶化和它们向水凝胶珠的转化。本研究的主要目的是调查海藻酸盐和氯化钙溶液的物理性质对海藻酸盐液滴形成和渗透到凝胶浴中，海藻酸钙珠的大小和形状的影响。采用高速摄像技术研究了熔滴在钙浴中的形成和熔滴的渗透过程。通过改变藻酸盐浓度（从10至30 g/L）来改变藻酸盐溶液的粘度，并且通过使用不同的水/甘油混合物（0-90%的甘油）来改变浴的粘度以制备CaCl 2溶液。在0.01 e1 g/L范围内，加入不同浓度的表面活性剂（Tween 20）可降低CaCl 2溶液的表面张力。液滴以眼泪形状从尖端脱离。在所有测试条件下，液滴在脱离后不到15 ms内达到球形，并且距离尖端不到25 mm。当动能足够高以打破钙浴的表面阻力并且液滴粘度足够高以避免变形时，获得球形珠粒。海藻酸钠液滴的渗透深度主要受CaCl 2溶液的粘度和表面张力的影响。随着CaCl_2溶液粘度和表面张力的增加，球形度降低，形状发生变形。表面活性剂的加入增强了渗透，并防止海藻酸钙珠的形状变形。(C)2016由Elsevier Ltd.出版
Currently, there is a growing interest for encapsulation of bioactive ingredients using calcium alginate microspheres or beads. Diffusion of the Ca in the alginate droplets provokes an ionic gelation and their conversion to hydrogel beads. The main objective of this study is to investigate the influence of physical properties of alginate and CaCl2 solutions on alginate droplet formation and penetration into gelling bath, in size and shape of Ca-alginate beads. The droplet formation and penetration in the calcium bath was investigated using a high-speed video recording. Viscosity of alginate solution was modified by changing the alginate concentration (from 10 to 30 g/L) and the viscosity of the bath was modified by using different water/glycerol mixes (0-90% of glycerol) to prepare the CaCl2 solution. Surface tension of CaCl2 solution is reduced by adding different concentrations of surfactants (Tween 20) in a range of 0.01 e1 g/L. Droplets detach from the tip with a tear shape. In all conditions tested, the droplets reach a spherical shape in less than 15 ms after detachment and less than 25 mm from the tip. Spherical beads are obtained when the kinetic energy is high enough to break the surface resistance of the calcium bath and droplet viscosity high enough to avoid deformations. Penetration depth of alginate droplets were mainly affected by viscosity and surface tension of CaCl2 solution. When viscosity and surface tension of CaCl2 solution increases, sphericity decrease and shape deformations are observed. The surfactant addition enhanced penetration and prevented shape deformations of Ca-alginate beads. (C) 2016 Published by Elsevier Ltd.