Reología Aplicada, Tecnología de Coloides, Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, c/P. García González, 1, E41012, Sevilla, Spain.
Reología Aplicada, Tecnología de Coloides, Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, c/P. García González, 1, E41012, Sevilla, Spain.
Colloids Surf B Biointerfaces. 2019 Jan 1;173:486-492. doi: 10.1016/j.colsurfb.2018.10.024. Epub 2018 Oct 10.
In the present work aqueous-based emulsions formulated with bio-based solvents and surfactants were studied. The droplet size distribution, rheology and physical stability of rosemary essential oil/water emulsions formulated with an emulsifier derived from wheat waste (alkyl polypentoside) were investigated as a function of the dispersed phase concentration (10-50 wt%) by means of laser diffraction, multiple light scattering and rheology measurements. Subsequently, processing variables, such as the pressure and the number of microfluidization passes, were studied to the best formulation (20 wt% rosemary oil). The laser diffraction technique revealed that monodispersed submicron emulsions were obtained for oil phase concentrations below 20 wt%. All emulsions showed Newtonian behavior, except for the emulsion containing 50 wt% oil, which exhibited shear-thinning properties. Moreover, the main destabilization mechanism of all the emulsions was creaming. The combination of techniques used demonstrated that the emulsion containing 20 wt% rosemary essential oil (REO) and prepared by microfluidization at 2500 psi (17.2 MPa) exhibited the longest physical stability and the smallest droplet size after 3passes. This research is a contribution to sustainable development not only by using chemicals derived from renewable raw materials but also by achieving stable emulsions with a low surfactant/oil mass ratio.
本工作研究了基于生物基溶剂和表面活性剂的水基乳液。通过激光衍射、多角度光散射和流变学测量，研究了由小麦废物衍生的乳化剂（烷基多糖苷）配制的迷迭香油/水乳液在分散相浓度（10-50wt%）下的粒径分布、流变学和物理稳定性。随后，研究了加工变量，如压力和微射流通过次数，以优化最佳配方（20wt%迷迭香油）。激光衍射技术表明，对于油相浓度低于 20wt%的乳液，可以得到单分散的亚微米乳液。所有乳液均表现出牛顿行为，除了含有 50wt%油的乳液外，该乳液表现出剪切稀化特性。此外，所有乳液的主要失稳机制均为乳析。所用技术的组合表明，在 2500psi（17.2MPa）下通过微射流制备的含有 20wt%迷迭香油的乳液在经过 3 次通过后具有最长的物理稳定性和最小的粒径。这项研究不仅通过使用源自可再生原料的化学品为可持续发展做出了贡献，而且还通过实现低表面活性剂/油质量比的稳定乳液做出了贡献。
