Microstructure evolution and partial coalescence in the whipping process of oleofoams stabilized by monoglycerides
Microstructure evolution and partial coalescence in the whipping process of oleofoams stabilized by monoglycerides
复制标题
单酸甘油酯稳定的油泡沫搅打过程中的微观结构演变和部分聚结
DOI：
10.1016/j.foodhyd.2020.106245
复制
发表时间：
2021-03-01
影响因子：
10.7
通讯作者：
Meng, Zong
中科院分区：
文献类型：
--
作者：
Du, Liyang;Jiang, Qinbo;Meng, Zong
Oleofoams是近年来发展迅速的新型脂肪基充气系统。采用不同的甘油单酯（MAG）浓度（3、5、7、9和11重量%）通过搅打油凝胶来结构化油泡沫。随着MAG浓度的增加，泡沫油中气泡排列更紧密，气泡尺寸分布更集中，界面弹性更强。此外，热分析结果表明，需要更多的热量来破坏更强的泡沫结构。因此，泡沫油的宏观和微观特征与MAG浓度密切相关，所有影响都可以通过包裹气泡的增厚晶体层和油相胶凝增强的组合来解释。此外，结晶网络和微观结构的演变提供了一个更直观的理解的泡沫油的发泡过程。结果表明，在搅打过程中，发泡体系中MAG晶体之间发生了部分聚结，界面处的部分聚结使发泡体系具有更强的泡沫结构和更好的发泡性能。然而，过度的搅打导致油泡沫中的部分聚结进一步发展并触发相邻气泡之间的晶体桥接，这部分地破坏了油-空气界面处的刚性三维结构。由于剪切作用下的晶体架桥，气泡间合并成形状不规则的大气泡，导致膨胀率降低，粒径分布不均匀，进而导致泡沫油质量有一定程度的下降。本研究对泡沫油的稳定性进行了更好、更深入的评价。
Oleofoams are novel fat-based aeration systems that have developed rapidly in recent years. Different mono glyceride (MAG) concentrations (3, 5, 7, 9 and 11 wt%) were employed to structure oleofoams through whipping oleogels. More tightly arranged bubbles, more concentrated bubble size distributions and stronger interfacial elasticity in oleofoams could be attributed to increasing MAG concentrations. Moreover, thermal results revealed that more heat were required to damage stronger foam structure. Thus, macro and micro characteristics of oleofoams were closely related to the MAG concentration, and all effects could be explained by a combination of the thickened crystal layer wrapped around bubbles and gelling enhancement in the oil phase. Furthermore, the evolution of crystal networks and microstructure provided a more intuitive understanding on the foaming process of oleofoams. It was clarified that partial coalescence between MAG crystals in oleofoams was happened during the whipping, and the partial coalescence at the interface provided stronger foam structure and desirable foam properties. However, excessive whipping led the partial coalescence in oleofoams to further develop and trigger crystal bridging between adjacent bubbles, which partially damaged rigid three-dimensional structure at the oil-air interface. Due to the crystal bridging under shearing, the merging between bubbles into larger bubbles with irregular shape led to a decrease in the overrun and uneven size distributions, and further, caused a certain degree of decline on the quality of oleofoams. This study allowed us to make a better and deeper assessment to the stability of oleofoams.