College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China.
Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Food Res Int. 2022 Jul;157:111451. doi: 10.1016/j.foodres.2022.111451. Epub 2022 Jun 2.
Zein nanoparticles are commonly used as colloidal emulsifiers to form and stabilize Pickering emulsions. However, the strong surface hydrophobicity of zein nanoparticles limits their widespread application. In this study, composite colloidal emulsifiers were fabricated from zein, sodium caseinate (NaCas), and epigallocatechin gallate (EGCG). Initially, NaCas-EGCG conjugates were formed using either an alkaline or enzymatic method. The enzymatic method led to conjugates containing more EGCG and with a higher thermal stability and surface hydrophilicity. Colloidal emulsifiers were prepared using an antisolvent precipitation method that involved titrating an ethanolic zein solution into an aqueous NaCas-EGCG conjugate solution. The potential application of these emulsifiers for forming and stabilizing high internal phase emulsions (HIPEs) was then explored. The emulsification properties of the zein nanoparticles were improved after they were complexed with NaCas-EGCG conjugates. Pickering HIPEs containing closely packed polygon oil droplets were formed from the colloidal emulsifiers, even at low particle concentrations (0.3% w/v). Overall, our results show that the functional performance of zein nanoparticles can be improved by complexing them with NaCas-EGCG conjugates. The novel colloidal emulsifiers developed in this study may therefore have useful applications in the food and other industries.
玉米醇溶蛋白纳米颗粒通常被用作胶体乳化剂，以形成和稳定 Pickering 乳液。然而，玉米醇溶蛋白纳米颗粒的强表面疏水性限制了其广泛应用。在本研究中，从玉米醇溶蛋白、酪蛋白酸钠（NaCas）和表没食子儿茶素没食子酸酯（EGCG）制备了复合胶体乳化剂。最初，使用碱性或酶法形成 NaCas-EGCG 缀合物。酶法导致含有更多 EGCG 的缀合物，且具有更高的热稳定性和表面亲水性。使用抗溶剂沉淀法制备胶体乳化剂，该方法涉及将乙醇玉米醇溶蛋白溶液滴定到含有 NaCas-EGCG 缀合物的水溶液中。然后探索了这些乳化剂在形成和稳定高内相比乳液（HIPE）中的潜在应用。玉米醇溶蛋白纳米颗粒与 NaCas-EGCG 缀合物复合后，其乳化性能得到改善。即使在低颗粒浓度（0.3%w/v）下，也可以从胶体乳化剂中形成具有紧密堆积多边形油滴的 Pickering HIPE。总的来说，我们的结果表明，通过与 NaCas-EGCG 缀合物复合，可以改善玉米醇溶蛋白纳米颗粒的功能性能。因此，本研究中开发的新型胶体乳化剂在食品和其他行业可能具有有用的应用。
