School of Food Science and Technology, Jiangnan University, Wuxi, 214122, P. R. China.
Future Food (Bai Ma) Research Institute, No. 111 Baima Road, Nanjing, 210000, P. R. China.
Food Funct. 2022 Aug 30;13(17):8860-8870. doi: 10.1039/d2fo01670b.
Aerated emulsions have widespread applications in the food industry. However, the poor stability of aerated emulsions remains a major challenge due to their inherent thermodynamic instability. Herein, a novel strategy to improve the foam stability of aerated emulsions using natural waxes was developed. Natural waxes including beeswax (BW), candelilla wax (CLW), carnauba wax (CW) and rice bran wax (RW), the bio-based and sustainable materials, displayed a high efficiency in improving the interfacial behavior, structural properties and foam stabilization of aerated emulsions. Compared with emulsions containing pure palm kernel stearin (PKS), the presence of waxes enhances the elastic modulus (') of air-liquid interfacial films and the viscosity () of the continuous phase. Interestingly, cryo-scanning electron microscopy (cryo-SEM) images revealed that the fat droplet shape was controlled by waxes. These were related to that waxes were conducive to the formation of larger and rigid fat crystals in fat droplets and facilitated effective piercing of the interface, promoting the fat coalescence. Waxes promoted the formation of partial coalescence in the plateau borders and the interface of the aerated emulsions, thus improving the foam stability. Furthermore, whipping experiments showed that the addition of 1.0-2.0 wt% waxes resulted in a shorter optimum whipping time and a higher overrun of aerated emulsions. The microstructure images showed that aerated emulsions with waxes displayed more numerous and uniform air bubbles. Finally, rheology experiments strongly supported that waxes strengthened the interface and network structure of aerated emulsions. Our observations revealed the mechanism of interaction between the natural wax-tuned interfacial behavior and the structure of aerated emulsions.
充气乳液在食品工业中有广泛的应用。然而，由于其内在的热力学不稳定性，充气乳液的稳定性差仍然是一个主要挑战。本文开发了一种使用天然蜡来提高充气乳液泡沫稳定性的新策略。包括蜂蜡 (BW)、坎地里拉蜡 (CLW)、巴西棕榈蜡 (CW) 和米糠蜡 (RW) 在内的天然蜡，作为生物基和可持续的材料，在提高充气乳液的界面行为、结构性能和泡沫稳定性方面显示出了很高的效率。与含有纯棕榈仁硬脂精 (PKS) 的乳液相比，蜡的存在提高了气液界面膜的弹性模量 (') 和连续相的粘度 ()。有趣的是，冷冻扫描电子显微镜 (cryo-SEM) 图像表明，蜡控制了脂肪滴的形状。这与蜡有利于在脂肪滴中形成更大和刚性的脂肪晶体以及有利于有效地刺穿界面、促进脂肪聚结有关。蜡促进了充气乳液的平台边界和界面处的部分聚结，从而提高了泡沫稳定性。此外，搅打实验表明，添加 1.0-2.0wt%的蜡会导致充气乳液的最佳搅打时间缩短，膨胀率提高。微观结构图像表明，含有蜡的充气乳液具有更多数量和更均匀的气泡。最后，流变学实验强烈支持蜡增强了充气乳液的界面和网络结构。我们的观察结果揭示了天然蜡调节的界面行为与充气乳液结构之间相互作用的机制。
