Abstract Recently, Pickering emulsions have attracted extensive interests due to their advantages of “surfactant-free” and sustained delivery for bioactives. However, developing natural, biodegradable and food grade nanoparticles as Pickering emulsion stabilizers face new challenges. In this study, zein/gum arabic (GA) complex colloidal nanoparticles (ZGAPs) were prepared with a core-shell structure through hydrogen bonding and electrostatic interactions. The mean size of ZGAPs was larger than that of zein nanoparticles, and the zeta potential reversed from positive to negative, further confirming that GA molecules adsorbed onto the surface of zein nanoparticles. The three-phase contact angle ( θ o/w ) of zein nanoparticles was around 133.75°. After addition of GA, the θ o/w of ZGAPs was adjusted to 88.95° closing to neutral wettability. This result indicated that ZGAPs could be developed as effective Pickering emulsifiers. Confocal laser scanning microscope images evidenced that ZGAPs formed a densely packed layer at the surface of oil droplets, which provided compact barriers of the droplets against coalescence and Ostwald ripening. At constant particle concentrations, the oil volume fraction significantly influenced the droplet sizes and rheological properties of Pickering emulsions. The droplet size and emulsified phase volume fraction of Pickering emulsions were increased with the rise of oil fraction. Consequently, Pickering emulsion gels were successfully fabricated at a higher oil fraction φ ≥ 0.5, which exhibited a long-term storage stability. These findings would provide a potential way of producing Pickering emulsion gels, which showed the advantages of both emulsions and gels, and could become novel and effective delivery systems of bioactives.

中文翻译：

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玉米蛋白/阿拉伯树胶复合胶体纳米粒子稳定的 Pickering 乳液凝胶的表征

摘要 近年来，Pickering 乳液因其“无表面活性剂”和生物活性物质持续传递的优势而引起了广泛的关注。然而，开发天然、可生物降解和食品级纳米粒子作为 Pickering 乳液稳定剂面临新的挑战。在这项研究中，通过氢键和静电相互作用制备了具有核壳结构的玉米醇溶蛋白/阿拉伯树胶 (GA) 复合胶体纳米粒子 (ZGAP)。ZGAPs的平均尺寸大于玉米醇溶蛋白纳米颗粒的平均尺寸，zeta电位从正反转为负，进一步证实了GA分子吸附在玉米醇溶蛋白纳米颗粒表面。玉米醇溶蛋白纳米颗粒的三相接触角 (θo/w) 约为 133.75°。添加 GA 后，ZGAP 的 θ o/w 被调整到 88.95°，接近于中性润湿性。该结果表明 ZGAPs 可以开发为有效的 Pickering 乳化剂。共聚焦激光扫描显微镜图像证明，ZGAPs 在油滴表面形成了一个致密的层，这为油滴提供了防止聚结和 Ostwald 成熟的致密屏障。在恒定颗粒浓度下，油体积分数显着影响 Pickering 乳液的液滴尺寸和流变特性。Pickering乳液的液滴尺寸和乳化相体积分数随着油分的增加而增加。因此，Pickering 乳液凝胶在较高的油分 φ ≥ 0.5 下成功制备，表现出长期储存稳定性。这些发现将提供一种生产 Pickering 乳液凝胶的潜在方法，