School of Chemical Engineering, University of Birmingham, Edgbaston, B15 2TT, UK.
School of Chemical Engineering, University of Birmingham, Edgbaston, B15 2TT, UK.
J Colloid Interface Sci. 2019 Mar 7;538:165-173. doi: 10.1016/j.jcis.2018.11.091. Epub 2018 Nov 24.
Polysaccharides such as kappa carrageenan are often utilised in fat replacement techniques in the food industry. However, the structural role they can provide within a product is limited by their hydrophilic nature. Hydrophilic particles can be surface-activated by hydrophobic modification e.g. in-situ interaction with a surfactant. This can drastically improve foam stability by providing a structural barrier around bubble interfaces offering protection against disproportionation and coalescence. Hence, it should be possible to bind negatively charged kappa carrageenan particles with a cationic surfactant through electrostatic interaction, in order to alter their surface properties.
Lauric arginate was mixed with kappa carrageenan microgel particles at various concentrations and the potential electrostatic interaction was studied using zeta potential, turbidity and rheological measurements. Mixtures were then aerated and foaming properties explored, in particular the location of the particles.
Lauric arginate was successfully bound to kappa carrageenan microgel particles. Consequently, particles were surface-activated and adsorbed at the air/water interface, as shown by optical and confocal microscopy. Foam half-life peaked at an intermediate surfactant concentration, where there was sufficient surfactant to coat particle surfaces but the concentration was low enough to prevent the formation of large aggregates unable to adsorb at the a/w interfaces.
角叉菜胶等多糖通常被用于食品工业中的脂肪替代技术。然而，由于其亲水性，它们在产品中所能提供的结构作用是有限的。亲水性颗粒可以通过疏水改性（例如，与表面活性剂的原位相互作用）进行表面激活。这可以通过在气泡界面周围提供结构屏障来提供保护，防止歧化和聚结，从而极大地提高泡沫稳定性。因此，应该可以通过静电相互作用将带负电荷的角叉菜胶颗粒与阳离子表面活性剂结合，从而改变其表面性质。
在不同浓度下将月桂酰精氨酸与角叉菜胶微凝胶颗粒混合，并使用zeta 电位、浊度和流变学测量研究潜在的静电相互作用。然后对混合物进行充气，并探索其发泡性能，特别是颗粒的位置。
月桂酰精氨酸成功地与角叉菜胶微凝胶颗粒结合。因此，如光学和共焦显微镜所示，颗粒被表面激活并吸附在气/水界面上。泡沫半衰期在中间表面活性剂浓度处达到峰值，此时有足够的表面活性剂来覆盖颗粒表面，但浓度足够低，以防止形成无法在 a/w 界面吸附的大聚集体。
