【作者】 李青； 马璐璐； 苏恩谊； 万芝力； 杨晓泉；

【Author】 Qing Li;Lulu Ma;Enyi Su;Zhili Wan;Xiaoquan Yang;Laboratory of Food Proteins and Colloids, School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology;

【机构】 植物蛋白与胶体研究中心广东省天然产物绿色加工与产品安全重点实验室华南理工大学食品科学与工程学院；

【摘要】 常用食品级起泡剂如蛋白质、小分子表面活性剂起泡性能有限,无法实现超稳态且具备环境刺激响应性的智能泡沫材料的制备。本文首次发现天然甜味剂皂苷甘草酸(Glycyrrhizic acid,GA)可作为起泡稳定剂,用于制造一种兼具超稳定性、热刺激响应性和良好加工性的新型多功能食品级泡沫。这种"超级泡沫"的产生是基于GA纳米纤维在气-水界面及连续水相中的多维空间可控自组装而实现的。小角度X射线散射结合显微镜成像结果表明,天然GA纳米纤维可快速吸附在气泡表面形成多层界面膜网络,同时连续相中的GA纤维通过氢键作用组装成高粘弹性的3D水凝胶网络。多维纤维网络的形成赋予了泡沫体系卓越的稳定性,纤维泡沫经数月甚至数年放置后仍可保持稳定且无排液(Liquid drainage)诱导的相分离现象出现。然而,加热(温度高于55-60°C)可引起纤维网络结构的融化裂解,使该超稳态泡沫快速失稳;因此,通过简单地改变环境温度,GA纤维泡沫可实现在稳态与非稳态之间的快速可逆切换,这主要是基于泡沫内部超分子GA纤维水凝胶网络的热可逆凝胶-溶胶相变行为而实现的。本文报道的由天然GA纤维制备的水基泡沫是一种兼具超稳定性、刺激响应性和可加工性的多功能软物质材料,其制备工艺绿色、简单,易于实现规模化生产,符合当今社会对环境友好、可持续发展的要求,这使得该泡沫材料在食品、药品及化妆品领域具有广阔的应用前景。更多还原

【Abstract】 A new class of food-grade foams that are ultrastable, thermostimulable, and processable can be created simply by using the naturally occurring saponin glycyrrhizic acid(GA) as the sole stabilizer. The creation of this "superfoam" is based on the spatially controllable self-assembly of supramolecular GA nanofibril hydrogelators at the air–water interface and in the continuous phase. The rapid adsorption of GA nanofibrils at the bubble surface, forming a multilayer interfacial network, combined with the formation of viscoelastic fibrillar hydrogel networks in the continuous phase, enables the foams having ultrastability over months or years without the water drainage induced phase separation, which have been evidenced using small angle X-ray scattering and microscopy techniques. Such ultrastable foams can be rapidly destabilized on demand by heating, which induces the melting of the fibrillar networks. These thermoresponsive foams can be reversibly switched between stable and unstable by simply changing the temperature, based on the reversible gel–sol phase transition of the supramolecular hydrogel inside the foam. This is the first finding of a natural edible surfactant system that foams very well and can be used solely to make advanced foams with the qualities of simplicity, ultrastability, stimulability, and processability, which make them viable for many sustainable applications.更多还原