Department of Chemical Engineering, Manhattan College, Riverdale, New York, USA.
Int J Cosmet Sci. 2022 Feb;44(1):30-41. doi: 10.1111/ics.12752. Epub 2021 Dec 5.
In this study, the biopolymers whey protein and chitosan were used to create a thermoresponsive emulsion. The impact of the inclusion of chitosan and inclusion of specific oils on the rheological properties and response to temperature were investigated by a stepwise build-up from simple solutions to oil-in-water (O/W) emulsions. Whey protein (WP) concentration and chitosan concentration were varied. The results may help develop strategies for incorporating thermoresponsive materials in stable and high-performing formulations for use in cosmetics.
Solutions of whey protein concentrate (WPC) by itself, chitosan by itself and the combination of the two at various concentrations were tested with flow sweeps, temperature sweeps and frequency sweeps. Then, three different oils of jojoba, avocado and silicone were included to form emulsions and the tests were repeated to determine flow behaviour, response to temperature and structure.
By comparing 15 wt. % and 20 wt. % WP solutions, it was found that 15 wt. % WP could provide good viscosities and modulus at a lower amount of material used. The solution composed of 15 wt. % WP, and 0.5 wt. % chitosan was found to have the greatest structural response to temperature compared to solutions with 1.0 wt. % and 1.5 wt. % chitosan. Compared to the addition of 10 wt. % silicone and 10 wt. % avocado oil to form emulsions, the addition of 10 wt. % jojoba oil further strengthened the gel network the most. The final emulsion with pigment added had improved viscosity and thermoresponsive behaviour. The WP and chitosan emulsions were shear thinning, elastically dominated and behaved as classical gels. The behaviour of the emulsions was dependent upon the hydrophobic interactions between the protein and the oil and the electrostatic interactions between the protein and the chitosan.
An emulsion composed of 15 wt. % WP, 10 wt. % jojoba oil and 0.5 wt. % chitosan solution was found to have the greatest structural response to temperature. This study of an O/W emulsion containing whey protein concentrate and chitosan demonstrated that different oils and conditions can be used to tune thermoresponsive and rheological behaviour.
在这项研究中，使用乳清蛋白和壳聚糖这两种生物聚合物来制备温敏乳液。通过从简单溶液逐步构建至水包油（O/W）乳液，研究了壳聚糖的包含和特定油的包含对流变性能和温度响应的影响。乳清蛋白（WP）浓度和壳聚糖浓度均有所变化。研究结果可能有助于制定策略，将温敏材料纳入稳定且性能优良的化妆品制剂中。
单独测试乳清蛋白浓缩物（WPC）、壳聚糖自身及其在不同浓度下的组合溶液，进行流变性扫频、温度扫频和频率扫频。然后，加入三种不同的油（霍霍巴油、鳄梨油和硅油）形成乳液，并重复进行测试以确定流动行为、温度响应和结构。
通过比较 15wt%和 20wt%的 WP 溶液，发现 15wt%的 WP 可以在使用较少材料的情况下提供良好的粘度和模量。与含有 1.0wt%和 1.5wt%壳聚糖的溶液相比，由 15wt%的 WP 和 0.5wt%的壳聚糖组成的溶液对温度的结构响应最大。与添加 10wt%硅油和 10wt%鳄梨油形成乳液相比，添加 10wt%霍霍巴油对凝胶网络的增强作用最大。添加颜料的最终乳液具有改善的粘度和温敏性。WP 和壳聚糖乳液呈剪切稀化、弹性主导且表现为典型的凝胶。乳液的行为取决于蛋白质与油之间的疏水性相互作用以及蛋白质与壳聚糖之间的静电相互作用。
发现由 15wt%WP、10wt%霍霍巴油和 0.5wt%壳聚糖溶液组成的乳液对温度的结构响应最大。这项含有乳清蛋白浓缩物和壳聚糖的 O/W 乳液的研究表明，可以使用不同的油和条件来调节温敏性和流变行为。
